Neuropsychological clustering highlights cognitive differences in young people presenting with depressive symptoms

Standalone Performance Validity Tests May Be Differentially Related to Measures of Working Memory, Processing Speed, and Verbal Memory in Patients With Multiple Sclerosis

Cognitive functioning may account for minimal levels (i.e., 5%-14%) of variance of performance validity test (PVT) scores in clinical examinees. The present study extended this research twofold: (a) by determining the variance cognitive functioning explains within three distinct PVTs (b) in a sample of patients with multiple sclerosis (pwMS). Seventy-five pwMS (Mage = 48.50, 70.6% female, 80.9% White) completed the Victoria Symptom Validity Test (VSVT), Word Choice Test (WCT), Dot Counting Test (DCT), and three objective measures of working memory, processing speed, and verbal memory as part of clinical neuropsychological assessment. Regression analyses in credible groups (ns ranged from 54 to 63) indicated that cognitive functioning explained 24% to 38% of the variance in logarithmically transformed PVT variables. Variance from cognitive testing differed across PVTs: verbal memory significantly influenced both VSVT and WCT scores; working memory influenced VSVT and DCT scores; and processing speed influenced DCT scores. The WCT appeared least related to cognitive functioning of the included PVTs. Alternative plausible explanations, including the apparent domain/modality specificity hypothesis of PVTs versus the potential sensitivity of these PVTs to neurocognitive dysfunction in pwMS were discussed. Continued psychometric investigations into factors affecting performance validity, especially in multiple sclerosis, are warranted.

The abnormal brain activation pattern of adolescents with major depressive disorder based on working memory tasks: A fNIRS study

OBJECTIVE

Although studies have confirmed that working memory (WM) is impaired among adults with major depressive disorder (MDD), generalizing these neurocognitive impairments to adolescents with MDD would be tenuous. Therefore, separate studies for adolescents with MDD are needed. Relatively little is known about the neural processes associated with WM dysfunction in adolescents with MDD. Thus, we examined whether adolescents with MDD have abnormal brain activation patterns compared to healthy controls (HC) during WM tasks and whether it was possible to distinguish adolescents with MDD and HC based on mean oxy-hemoglobin (Oxy-Hb) changes.

METHOD

A total of 87 adolescents with MDD and 63 HC were recruited. Functional near-infrared spectroscopy (fNIRS) was performed to monitor the concentrations of Oxy-Hb in the frontotemporal lobe while participants performed three WM tasks in order to examine WM impairments in adolescents with depression.

RESULTS

The mean changes in Oxy-Hb concentrations in the left prefrontal cortex and right prefrontal cortex were higher among HC than among patients during the encoding and maintenance phase under each WM-load task. Machine learning was used to distinguish adolescents with MDD and HC based on Oxy-Hb changes, with a moderate area under the curve of 0.84.

CONCLUSIONS

This study revealed WM defects in adolescents with MDD compared to HC based on mean Oxy-Hb changes, which can be valuable for distinguishing adolescents with MDD from HC.

Prevalence of cognitive impairments and strengths in the early course of psychosis and depression

BACKGROUND

Studies investigating cognitive impairments in psychosis and depression have typically compared the average performance of the clinical group against healthy controls (HC), and do not report on the actual prevalence of cognitive impairments or strengths within these clinical groups. This information is essential so that clinical services can provide adequate resources to supporting cognitive functioning. Thus, we investigated this prevalence in individuals in the early course of psychosis or depression.

METHODS

A comprehensive cognitive test battery comprising 12 tests was completed by 1286 individuals aged 15-41 (mean age 25.07, s.d. 5.88) from the PRONIA study at baseline: HC (N = 454), clinical high risk for psychosis (CHR; N = 270), recent-onset depression (ROD; N = 267), and recent-onset psychosis (ROP; N = 295). Z-scores were calculated to estimate the prevalence of moderate or severe deficits or strengths (>2 s.d. or 1-2 s.d. below or above HC, respectively) for each cognitive test.

RESULTS

Impairment in at least two cognitive tests was as follows: ROP (88.3% moderately, 45.1% severely impaired), CHR (71.2% moderately, 22.4% severely impaired), ROD (61.6% moderately, 16.2% severely impaired). Across clinical groups, impairments were most prevalent in tests of working memory, processing speed, and verbal learning. Above average performance (>1 s.d.) in at least two tests was present for 40.5% ROD, 36.1% CHR, 16.1% ROP, and was >2 SDs in 1.8% ROD, 1.4% CHR, and 0% ROP.

CONCLUSIONS

These findings suggest that interventions should be tailored to the individual, with working memory, processing speed, and verbal learning likely to be important transdiagnostic targets.

A transdiagnostic view on MDD and ADHD: shared cognitive characteristics?

BACKGROUND

Major Depressive disorder (MDD) and Attention Deficit Hyperactivity Disorder (ADHD) are prevalent mental disorders that often co-occur. There is overlap in symptomatology between MDD and ADHD that complicates diagnostics and treatment selection. Hence, to aid diagnostics of single and comorbid disorders, we aimed to examine the discriminative power of common symptom measures and cognitive dysfunction to differentiate between participants diagnosed with MDD, ADHD, ADHD and comorbid MDD and without a mental disorder.

METHODS

Four diagnosed groups were compared: MDD (n = 103), ADHD (n = 78), comorbid MDD + ADHD (n = 29), healthy controls (HC; n = 123). We examined between-group differences and discriminative functions of clinically validated self-report symptom questionnaires, as well as task-based and self-report measures of cognitive dysfunction.

RESULTS

Based on the between group comparisons, all patient groups were characterized by clinically relevant levels of ADHD-symptomatology, executive dysfunction, and diminished cognitive performances in the domain of attention; even the MDD-only group. In addition, based on self-reported symptoms of MDD, ADHD, and executive dysfunction, discriminant function analysis classified all HC correctly (100%) and patients diagnosed with ADHD or MDD relatively well (resp. 85% and 82%). Comorbid MDD + ADHD was poorly differentiated from single MDD or ADHD by the commonly used self-report symptom questionnaires for MDD and ADHD (0% correct predictions), which substantially improved by incorporating the questionnaire on executive functioning (42% correct predictions).

CONCLUSIONS

In both MDD and ADHD, clinical levels of attentional and executive dysfunction were found, while these clinical groups differed in cognitive flexibility, initiating, inhibition and meta-cognition. Comorbid MDD + ADHD was poorly distinguishable from non-comorbid MDD and ADHD based on self-reported symptoms of depression and ADHD. Addition of subjective executive function in the discrimination models resulted in increased discriminative power. Our findings indicate that executive functioning measure can improve the diagnostic process of ADHD and MDD.

Atypical Functional Network Properties and Associated Dimensions of Child Psychopathology During Rest and Task Performance

Background

When brain networks deviate from typical development, this is thought to contribute to varying forms of psychopathology. However, research has been limited by the reliance on discrete diagnostic categories that overlook the potential for psychological comorbidity and the dimensional nature of symptoms.

Methods

This study examined the topology of functional networks in association with 4 bifactor-defined psychopathology dimensions-general psychopathology, internalizing symptoms, conduct problems, and attention-deficit/hyperactivity disorder symptoms-via the Child Behavior Checklist in a sample of 3568 children from the ABCD (Adolescent Brain Cognitive Development) Study. Local and global graph theory metrics were calculated at rest and during tasks of reward processing, inhibition, and working memory.

Results

Greater attention-deficit/hyperactivity disorder symptoms were associated with reduced modularity across rest and tasks as well as reduced local efficiency in motor networks at rest. Results survived sensitivity analyses for medication and socioeconomic status. Greater conduct problem symptoms were associated with reduced modularity on working memory and reward processing tasks; however, these results did not persist after sensitivity analyses. General psychopathology and internalizing symptoms showed no significant network associations.

Conclusions

Our findings suggest reduced efficiency in topology in those with greater attention-deficit/hyperactivity disorder symptoms across 4 critical cognitive states, with conduct problems also showing network deficits, although less consistently. This may suggest that modularity deficits are a neurobiological marker of externalizing behavior in children. Such specificity has not been demonstrated before using graph theory metrics and has the potential to redefine our understanding of network deficits in children with psychopathology symptoms.

Association of Major Depressive Disorder with remotely administered measures of cognition and subjective report of cognitive difficulties across the adult age spectrum

BACKGROUND

Major depressive disorder (MDD) has increasing prevalence with age. Both objective measures of cognitive dysfunction and subjective report of cognitive difficulties related to MDD are often thought to worsen with increasing age. However, few studies have directly evaluated these characteristics across the adult lifespan.

METHODS

Participants included 23,594 adults completing objective and subjective measures of cognition on an online research registry. Linear regression including interactions of age group with depression was used to evaluate the association of self-reported MDD with measures of cognition in three age groups: 21-40 years; 41-60 years; 61+ years.

RESULTS

MDD (n = 2127) demonstrated poorer objective cognitive performance and greater subjective ratings of cognitive difficulties across all domains assessed compared to non-depressed individuals (ND; n = 21,467). Significant interactions of age group and MDD status with objective and subjective measures of cognition were observed for both middle age and older adults when compared to young adults but few significant differences between middle-aged and older adults were evident.

LIMITATIONS

This study relied on self-report of MDD diagnosis, utilized remotely administered and unsupervised measures of cognition, and the sample was not diverse.

CONCLUSIONS

The magnitude of association between MDD and cognitive correlates appears to plateau in middle age. Our results suggest that increased rates of dementia are not due to greater cognitive consequence of MDD in older adults and that age effects, and not greater effects of depression, may lead to increased diagnosis of MDD based on subjective report of cognitive symptoms.

Data-driven cognitive phenotypes in subjects with bipolar disorder and their clinical markers of severity

BACKGROUND

Subjects with bipolar disorder (BD) show heterogeneous cognitive profile and that not necessarily the disease will lead to unfavorable clinical outcomes. We aimed to identify clinical markers of severity among cognitive clusters in individuals with BD through data-driven methods.

METHODS

We recruited 167 outpatients with BD and 100 unaffected volunteers from Brazil and Spain that underwent a neuropsychological assessment. Cognitive functions assessed were inhibitory control, processing speed, cognitive flexibility, verbal fluency, working memory, short- and long-term verbal memory. We performed hierarchical cluster analysis and discriminant function analysis to determine and confirm cognitive clusters, respectively. Then, we used classification and regression tree (CART) algorithm to determine clinical and sociodemographic variables of the previously defined cognitive clusters.

RESULTS

We identified three neuropsychological subgroups in individuals with BD: intact (35.3%), selectively impaired (34.7%), and severely impaired individuals (29.9%). The most important predictors of cognitive subgroups were years of education, the number of hospitalizations, and age, respectively. The model with CART algorithm showed sensitivity 45.8%, specificity 78.4%, balanced accuracy 62.1%, and the area under the ROC curve was 0.61. Of 10 attributes included in the model, only three variables were able to separate cognitive clusters in BD individuals: years of education, number of hospitalizations, and age.

CONCLUSION

These results corroborate with recent findings of neuropsychological heterogeneity in BD, and suggest an overlapping between premorbid and morbid aspects that influence distinct cognitive courses of the disease.

Neurobiology Youth Follow-up Study: protocol to establish a longitudinal and prospective research database using multimodal assessments for current and past mental health treatment-seeking young people within an early intervention service

INTRODUCTION

Approximately 75% of major mental illness occurs before the age of 25 years. Despite this, our capacity to provide effective, early and personalised interventions is limited by insufficient evidence for characterising early-stage, and less specific, presentations of major mental disorders in youth populations. This article describes the protocol for setting up a large-scale database that will collect longitudinal, prospective data that incorporate clinical, social and occupational function, neuropsychological, circadian, metabolic, family history and genetic metrics. By collecting data in a research-purposed, standardised manner, the 'Neurobiology Youth Follow-up Study' should improve identification, characterisation and profiling of youth attending mental healthcare, to better inform diagnosis and treatment at critical time points. The overall goal is enhanced long-term clinical and functional outcomes.

METHODS AND ANALYSIS

This longitudinal clinical cohort study will invite participation from youth (12-30 years) who seek help for mental health-related issues at an early intervention service (headspace Camperdown) and linked services. Participants will be prospectively tracked over 3 years with a series of standardised multimodal assessments at baseline, 6, 12, 24 and 36 months. Evaluations will include: (1) clinician-administered and self-report assessments determining clinical stage, pathophysiological pathways to illness, diagnosis, symptomatology, social and occupational function; (2) neuropsychological profile; (3) sleep-wake patterns and circadian rhythms; (4) metabolic markers and (5) genetics. These data will be used to: (1) model the impact of demographic, phenomenological and treatment variables, on clinical and functional outcomes; (2) map neurobiological profiles and changes onto a transdiagnostic clinical stage and pathophysiological mechanisms framework.

ETHICS AND DISSEMINATION

This study protocol has been approved by the Human Research Ethics Committee of the Sydney Local Health District (2020/ETH01272, protocol V.1.3, 14 October 2020). Research findings will be disseminated through peer-reviewed journals and presentations at scientific conferences and to user and advocacy groups. Participant data will be de-identified.

Habitual versus affective motivations in obsessive-compulsive disorder and alcohol use disorder

OBJECTIVE

To (1) confirm whether the Habit, Reward, and Fear Scale is able to generate a 3-factor solution in a population of obsessive-compulsive disorder and alcohol use disorder (AUD) patients; (2) compare these clinical groups in their habit, reward, and fear motivations; and (3) investigate whether homogenous subgroups can be identified to resolve heterogeneity within and across disorders based on the motivations driving ritualistic and drinking behaviors.

METHODS

One hundred and thirty-four obsessive-compulsive disorder (n = 76) or AUD (n = 58) patients were assessed with a battery of scales including the Habit, Reward, and Fear Scale, the Yale-Brown Obsessive-Compulsive Scale, the Alcohol Dependence Scale, the Behavioral Inhibition/Activation System Scale, and the Urgency, (lack of ) Premeditation, (lack of ) Perseverance, Sensation Seeking, and Positive Urgency Impulsive Behavior Scale.

RESULTS

A 3-factor solution reflecting habit, reward, and fear subscores explained 56.6% of the total variance of the Habit, Reward, and Fear Scale. Although the habit and fear subscores were significantly higher in obsessive-compulsive disorder (OCD) and the reward subscores were significantly greater in AUD patients, a cluster analysis identified that the 3 clusters were each characterized by differing proportions of OCD and AUD patients.

CONCLUSIONS

While affective (reward- and fear-driven) and nonaffective (habitual) motivations for repetitive behaviors seem dissociable from each other, it is possible to identify subgroups in a transdiagnostic manner based on motivations that do not match perfectly motivations that usually described in OCD and AUD patients.

Neurocognitive and functional heterogeneity in depressed youth

Depression is a common psychiatric illness that often begins in youth, and is sometimes associated with cognitive deficits. However, there is significant variability in cognitive dysfunction, likely reflecting biological heterogeneity. We sought to identify neurocognitive subtypes and their neurofunctional signatures in a large cross-sectional sample of depressed youth. Participants were drawn from the Philadelphia Neurodevelopmental Cohort, including 712 youth with a lifetime history of a major depressive episode and 712 typically developing (TD) youth matched on age and sex. A subset (MDD n = 368, TD n = 200) also completed neuroimaging. Cognition was assessed with the Penn Computerized Neurocognitive Battery. A recently developed semi-supervised machine learning algorithm was used to delineate neurocognitive subtypes. Subtypes were evaluated for differences in both clinical psychopathology and brain activation during an n-back working memory fMRI task. We identified three neurocognitive subtypes in the depressed group. Subtype 1 was high-performing (high accuracy, moderate speed), Subtype 2 was cognitively impaired (low accuracy, slow speed), and Subtype 3 was impulsive (low accuracy, fast speed). While subtypes did not differ in clinical psychopathology, they diverged in their activation profiles in regions critical for executive function, which mirrored differences in cognition. Taken together, these data suggest disparate mechanisms of cognitive vulnerability and resilience in depressed youth, which may inform the identification of biomarkers for prognosis and treatment response.

Neurocognitive functioning predicts suicidal behaviour in young people with affective disorders

BACKGROUND

Neurocognitive impairment is recognised as a risk factor for suicidal behaviour in adults. The current study aims to determine whether neurocognitive deficits also predict ongoing or emergent suicidal behaviour in young people with affective disorders.

METHODS

Participants were aged 12-30 years and presented to early intervention youth mental health clinics between 2008 and 2018. In addition to clinical assessment a standardised neurocognitive assessment was conducted at baseline. Clinical data was extracted from subsequent visits using a standardised proforma.

RESULTS

Of the 635 participants who met inclusion criteria (mean age 19.6 years, 59% female, average follow up 476 days) 104 (16%) reported suicidal behaviour during care. In 5 of the 10 neurocognitive domains tested (cognitive flexibility, processing speed, working memory, verbal memory and visuospatial memory) those with suicidal behaviour during care were superior to clinical controls. Better general neurocognitive function remained a significant predictor (OR=1.94, 95% CI 1.29- 2.94) of suicidal behaviour in care after controlling for other risk factors.

LIMITATIONS

The neurocognitive battery used was designed for use with affective and psychotic disorders and may not have detected some deficits more specific to suicidal behaviour.

CONCLUSION

Contrary to expectations, better neurocognitive functioning predicts suicidal behaviour during care in young people with affective disorders. While other populations with suicidal behaviour, such as adults with affective disorders or young people with psychotic disorders, tend to experience neurocognitive deficits which may limit their capacity to engage in some interventions, this does not appear to be the case for young people with affective disorders.

A Novel Approach for Cognitive Clustering of Parkinsonisms through Affinity Propagation

Cluster analysis is widely applied in the neuropsychological field for exploring patterns in cognitive profiles, but traditional hierarchical and non-hierarchical approaches could be often poorly effective or even inapplicable on certain type of data. Moreover, these traditional approaches need the initial specification of the number of clusters, based on a priori knowledge not always owned. For this reason, we proposed a novel method for cognitive clustering through the affinity propagation (AP) algorithm. In particular, we applied the AP clustering on the regression residuals of the Mini Mental State Examination scores—a commonly used screening tool for cognitive impairment—of a cohort of 49 Parkinson’s disease, 48 Progressive Supranuclear Palsy and 44 healthy control participants. We found four clusters, where two clusters (68 and 30 participants) showed almost intact cognitive performance, one cluster had a moderate cognitive impairment (34 participants), and the last cluster had a more extensive cognitive deficit (8 participants). The findings showed, for the first time, an intra- and inter-diagnostic heterogeneity in the cognitive profile of Parkinsonisms patients. Our novel method of unsupervised learning could represent a reliable tool for supporting the neuropsychologists in understanding the natural structure of the cognitive performance in the neurodegenerative diseases.

Protocol for a young adult mental health (Uspace) cohort: personalising multidimensional care in young people admitted to hospital

INTRODUCTION

Currently, the literature on personalised and measurement-based mental healthcare is inadequate with major gaps in the development and evaluation of 21st century service models. Clinical presentations of mental ill health in young people are heterogeneous, and clinical and functional outcomes are often suboptimal. Thus, treatments provided in a person-centred and responsive fashion are critical to meet the unique needs of young people and improve individual outcomes. Personalised care also requires concurrent assessment of factors relating to outcomes and underlying neurobiology. This study builds on a completed feasibility study and will be the first to incorporate clinical, cognitive, circadian, metabolic and hormonal profiling with personalised and measurement-based care in a cohort of young people admitted to hospital.

METHODS AND ANALYSIS

This prospective, transdiagnostic, observational study will be offered to all young people between the ages of 16 and 30 years admitted to the inpatient unit of the participating centre. In total, 400 participants will be recruited. On admission to hospital, young people will undergo clinical and diagnostic assessment, cognitive testing, self-report questionnaires, metabolic and hormonal data collection, and anthropomorphic measurements. Participants will wear an actigraphy watch for at least 1 week during admission to measure circadian patterns and sleep-wake cycles. A feedback session between clinician and participant will occur after clinical and other laboratory assessments to tailor individual treatment plans, explain the ongoing process of measurement-based care, and provide participant and family education. Associations between cognitive impairments, disturbed sleep-wake behaviours, circadian rhythms, clinical symptoms and functional impairments will be evaluated to improve the understanding of parameters affecting clinical outcomes.

ETHICS AND DISSEMINATION

This study protocol was approved by the Human Research Ethics Committees of the University of Sydney (HREC USYD 2015/867) and St Vincent's Hospital (HREC SVH 17/045). This study will be published on completion in a peer-reviewed journal.

The Mediated Moderation Model of Depressive Symptoms, Alcohol Use, and Consequences: The Protective Role of Executive Function

Heavy episodic drinking (HED) and negative drinking consequences represent prevalent and serious health concerns for college students. Depressive symptoms may elevate students' risk for engaging in HED and experiencing negative consequences, but levels of risk may vary by executive function (EF) capabilities. Growing evidence suggests that EF deficits are associated with comorbid depressive symptoms and alcohol misuse. Nevertheless, little is known about unique and shared risks that depressive symptoms and EF may interactively pose for HED and negative drinking consequences. Methods: To address these gaps, the study assessed depressive symptoms, multiple domains of EF via multimethod approach, HED, and negative drinking consequences in a sample of 446 undergraduate students. Mediated moderation models were conducted to examine associations between depressive symptoms and alcohol use behaviors and modulating roles of EF. Results: Depressive symptoms, poor planning, and self-reported executive dysfunction were significantly associated with HED and negative drinking consequences. HED mediated the effect of depressive symptoms and executive dysfunction on negative consequences. A significant interaction indicated that better EF (i.e. low or average self-reported executive dysfunction) may buffer the risk depressive symptoms present for negative drinking consequences. Conclusions: The current findings suggest that among college students, risk and resilience factors for HED and negative drinking consequences may vary. Effective EF capabilities may be especially helpful for reducing students' risk for more serious drinking consequences.

Expanding the search for emerging mental ill health to safeguard student potential and vocational success in high school: A narrative review

AIM

Young people experiencing mental ill health are more likely than their healthy aged peers to drop out of high school. This can result in social exclusion and vocational derailment. Identifying young people at risk and taking action before an illness is established or school dropout occurs is an important goal. This study aimed to examine evidence for the risk markers and at risk mental states of the clinical staging model (stage 0-1b) and whether these risk states and early symptoms impact school participation and academic attainment.

METHOD

This narrative review assembles research from both the psychiatry and education literature. It examines stage 0 to stage 1b of the clinical staging model and links the risk states and early symptoms to evidence about the academic success of young people in high school.

RESULTS

In accordance with the clinical staging model and evidence from education literature, childhood trauma and parental mental illness can impact school engagement and academic progress. Sleep disturbance can result in academic failure. Undifferentiated depression and anxiety can increase the risk for school dropout. Subthreshold psychosis and hypomanic states are associated with functional impairment and high rates of Not in Employment, Education, or Training (NEET) but are not recognized in the education literature.

CONCLUSION

Risk markers for emerging mental ill health can be identified in education research and demonstrate an impact on a student's success in high school. Clear referral protocols need to be embedded into school life to reduce risk of progression to later stages of illness and support school participation and success.

Predictors of cognitive impairment in treatment-resistant depression

BACKGROUND

Cognitive impairment is a well-recognized symptom of major depressive disorder; however, contributing factors are not fully characterized. The present study examined the neurocognitive profiles and predictors of cognitive impairment in patients with treatment-resistant depression (TRD).

METHODS

Moderate to severely depressed TRD patients were compared to matched healthy volunteers (HV) in verbal learning and recall and executive functions. Based on cognitive scores, cluster analysis was performed to identify subsets within the TRD sample. Predictors of cognitive impairment were also investigated.

RESULTS

TRD patients showed worse performance in tests assessing verbal memory, executive attentional shifting, and inhibitory control. The cluster analysis revealed two groups: a cognitively impaired (CI) group that showed a generalized deficit across cognitive domains, and a relatively cognitively intact group that performed better than CI in all domains except attentional shifting. A logistic binomial regression of the two groups revealed three significant contributing risk factors for CI: 1) older age, 2) lower premorbid IQ, and 3) benzodiazepine use. Cognitive impairment and benzodiazepine use were associated with worse functioning.

CONCLUSIONS

Significant cognitive impairment is present in TRD and is associated with worse functioning. Age, lower premorbid IQ, and benzodiazepine use increased the likelihood of generalized cognitive impairment in TRD patients. The detrimental effect of benzodiazepine on cognitive impairment is independent of anxiety symptoms. Further research is needed to characterize the timeline of cognitive impairment in depression.

Exploring the complex inter-relations between internalising symptoms, executive functioning and alcohol use in young adults

OBJECTIVE

Globally, the prevalence of hazardous drinking peaks in young adulthood, and there is mixed evidence on whether internalising symptoms and executive functioning deficits are associated with this increased risk. This study tested whether internalising symptoms in interaction with executive functioning deficits are associated with high alcohol use disorder symptoms in emerging adulthood, via drinking motives to cope with negative affect and alcohol consumption.

METHOD

An Australian sample of 155 young adults aged 17 to 24 years (M = 20.97, SD = 2.40) provided self-report data on internalising symptom severity and alcohol-related outcomes (n = 155), and neuropsychological data measuring executive functioning (n = 104). Confirmatory factor analyses were conducted to identify two latent variables representing internalising symptoms and executive functions. A series of latent moderated structural equation models and a latent mediated moderation structural equation model examined the inter-relations between internalising symptoms, executive functions and alcohol measures.

RESULTS

High levels of internalising symptoms in interaction with executive functioning deficits were associated with strong drinking motives to cope with negative affect, high past month alcohol consumption and greater alcohol use disorder symptoms. Drinking motives to cope with negative affect and alcohol consumption mediated the relationship between the internalising symptoms and executive functioning latent interaction term with alcohol use disorder symptoms.

CONCLUSIONS

This research highlights greater executive functioning resources are associated with low desires to drink hazardous amounts of alcohol as a maladaptive way to cope with negative feelings among young people. It therefore may be useful to target executive functioning ability alongside internalising symptomology in alcohol prevention and intervention initiatives.

Using Two-Step Cluster Analysis and Latent Class Cluster Analysis to Classify the Cognitive Heterogeneity of Cross-Diagnostic Psychiatric Inpatients

The heterogeneity of cognitive profiles among psychiatric patients has been reported to carry significant clinical information. However, how to best characterize such cognitive heterogeneity is still a matter of debate. Despite being well suited for clinical data, cluster analysis techniques, like the Two-Step and the Latent Class, received little to no attention in the literature. The present study aimed to test the validity of the cluster solutions obtained with Two-Step and Latent Class cluster analysis on the cognitive profile of a cross-diagnostic sample of 387 psychiatric inpatients. Two-Step and Latent Class cluster analysis produced similar and reliable solutions. The overall results reported that it is possible to group all psychiatric inpatients into Low and High Cognitive Profiles, with a higher degree of cognitive heterogeneity in schizophrenia and bipolar disorder patients than in depressive disorders and personality disorder patients.

Neurocognitive heterogeneity across the spectrum of psychopathology: need for improved approaches to deficit detection and intervention

Neurocognition is one of the strongest predictors of clinical and functional outcomes across the spectrum of psychopathology, yet there remains a dearth of unified neurocognitive nosology and available neurocognition-targeted interventions. Neurocognitive deficits manifest in a transdiagnostic manner, with no psychiatric disorder uniquely affiliated with one specific deficit. In fact, recent research has identified that essentially all investigated disorders are comprised of 3-4 neurocognitive profiles. This within-disorder neurocognitive heterogeneity has hampered the development of novel, neurocognition-targeted interventions, as only a portion of patients with any given disorder possess neurocognitive deficits that would warrant neurocognitive intervention. The development of criteria and terminology to characterize these neurocognitive deficit syndromes would provide clinicians with the opportunity to more systematically identify and treat their patients and provide researchers the opportunity to develop neurocognition-targeted interventions for patients. This perspective will summarize recent work and discuss possible approaches for neurocognition-focused diagnosis and treatment in psychiatry.

Transdiagnostic neurocognitive subgroups and functional course in young people with emerging mental disorders: a cohort study

BACKGROUND

Neurocognitive impairments robustly predict functional outcome. However, heterogeneity in neurocognition is common within diagnostic groups, and data-driven analyses reveal homogeneous neurocognitive subgroups cutting across diagnostic boundaries.

AIMS

To determine whether data-driven neurocognitive subgroups of young people with emerging mental disorders are associated with 3-year functional course.

METHOD

Model-based cluster analysis was applied to neurocognitive test scores across nine domains from 629 young people accessing mental health clinics. Cluster groups were compared on demographic, clinical and substance-use measures. Mixed-effects models explored associations between cluster-group membership and socio-occupational functioning (using the Social and Occupational Functioning Assessment Scale) over 3 years, adjusted for gender, premorbid IQ, level of education, depressive, positive, negative and manic symptoms, and diagnosis of a primary psychotic disorder.

RESULTS

Cluster analysis of neurocognitive test scores derived three subgroups described as 'normal range' (n = 243, 38.6%), 'intermediate impairment' (n = 252, 40.1%), and 'global impairment' (n = 134, 21.3%). The major mental disorder categories (depressive, anxiety, bipolar, psychotic and other) were represented in each neurocognitive subgroup. The global impairment subgroup had lower functioning for 3 years of follow-up; however, neither the global impairment (B = 0.26, 95% CI -0.67 to 1.20; P = 0.581) or intermediate impairment (B = 0.46, 95% CI -0.26 to 1.19; P = 0.211) subgroups differed from the normal range subgroup in their rate of change in functioning over time.

CONCLUSIONS

Neurocognitive impairment may follow a continuum of severity across the major syndrome-based mental disorders, with data-driven neurocognitive subgroups predictive of functional course. Of note, the global impairment subgroup had longstanding functional impairment despite continuing engagement with clinical services.

Right care, first time: a highly personalised and measurement-based care model to manage youth mental health

Mood and psychotic syndromes most often emerge during adolescence and young adulthood, a period characterised by major physical and social change. Consequently, the effects of adolescent-onset mood and psychotic syndromes can have long term consequences. A key clinical challenge for youth mental health is to develop and test new systems that align with current evidence for comorbid presentations and underlying neurobiology, and are useful for predicting outcomes and guiding decisions regarding the provision of appropriate and effective care. Our highly personalised and measurement-based care model includes three core concepts: ▶ A multidimensional assessment and outcomes framework that includes: social and occupational function; self-harm, suicidal thoughts and behaviour; alcohol or other substance misuse; physical health; and illness trajectory. ▶ Clinical stage. ▶ Three common illness subtypes (psychosis, anxious depression, bipolar spectrum) based on proposed pathophysiological mechanisms (neurodevelopmental, hyperarousal, circadian). The model explicitly aims to prevent progression to more complex and severe forms of illness and is better aligned to contemporary models of the patterns of emergence of psychopathology. Inherent within this highly personalised approach is the incorporation of other evidence-based processes, including real-time measurement-based care as well as utilisation of multidisciplinary teams of health professionals. Data-driven local system modelling and personalised health information technologies provide crucial infrastructure support to these processes for better access to, and higher quality, mental health care for young people. CHAPTER 1: MULTIDIMENSIONAL OUTCOMES IN YOUTH MENTAL HEALTH CARE: WHAT MATTERS AND WHY?: Mood and psychotic syndromes present one of the most serious public health challenges that we face in the 21st century. Factors including prevalence, age of onset, and chronicity contribute to substantial burden and secondary risks such as alcohol or other substance misuse. Mood and psychotic syndromes most often emerge during adolescence and young adulthood, a period characterised by major physical and social change; thus, effects can have long term consequences. We propose five key domains which make up a multidimensional outcomes framework that aims to address the specific needs of young people presenting to health services with emerging mental illness. These include social and occupational function; self-harm, suicidal thoughts and behaviours; alcohol or other substance misuse; physical health; and illness type, stage and trajectory. Impairment and concurrent morbidity are well established in young people by the time they present for mental health care. Despite this, services and health professionals tend to focus on only one aspect of the presentation - illness type, stage and trajectory - and are often at odds with the preferences of young people and their families. There is a need to address the disconnect between mental health, physical health and social services and interventions, to ensure that youth mental health care focuses on the outcomes that matter to young people. CHAPTER 2: COMBINING CLINICAL STAGE AND PATHOPHYSIOLOGICAL MECHANISMS TO UNDERSTAND ILLNESS TRAJECTORIES IN YOUNG PEOPLE WITH EMERGING MOOD AND PSYCHOTIC SYNDROMES: Traditional diagnostic classification systems for mental disorders map poorly onto the early stages of illness experienced by young people, and purport categorical distinctions that are not readily supported by research into genetic, environmental and neurobiological risk factors. Consequently, a key clinical challenge in youth mental health is to develop and test new classification systems that align with current evidence on comorbid presentations, are consistent with current understanding of underlying neurobiology, and provide utility for predicting outcomes and guiding decisions regarding the provision of appropriate and effective care. This chapter outlines a transdiagnostic framework for classifying common adolescent-onset mood and psychotic syndromes, combining two independent but complementary dimensions: clinical staging, and three proposed pathophysiological mechanisms. Clinical staging reflects the progression of mental disorders and is in line with the concept used in general medicine, where more advanced stages are associated with a poorer prognosis and a need for more intensive interventions with a higher risk-to-benefit ratio. The three proposed pathophysiological mechanisms are neurodevelopmental abnormalities, hyperarousal and circadian dysfunction, which, over time, have illness trajectories (or pathways) to psychosis, anxious depression and bipolar spectrum disorders, respectively. The transdiagnostic framework has been evaluated in young people presenting to youth mental health clinics of the University of Sydney's Brain and Mind Centre, alongside a range of clinical and objective measures. Our research to date provides support for this framework, and we are now exploring its application to the development of more personalised models of care. CHAPTER 3: A COMPREHENSIVE ASSESSMENT FRAMEWORK FOR YOUTH MENTAL HEALTH: GUIDING HIGHLY PERSONALISED AND MEASUREMENT-BASED CARE USING MULTIDIMENSIONAL AND OBJECTIVE MEASURES: There is an urgent need for improved care for young people with mental health problems, in particular those with subthreshold mental disorders that are not sufficiently severe to meet traditional diagnostic criteria. New comprehensive assessment frameworks are needed to capture the biopsychosocial profile of a young person to drive highly personalised and measurement-based mental health care. We present a range of multidimensional measures involving five key domains: social and occupational function; self-harm, suicidal thoughts and behaviours; alcohol or other substance misuse; physical health; and illness type, stage and trajectory. Objective measures include: neuropsychological function; sleep-wake behaviours and circadian rhythms; metabolic and immune markers; and brain structure and function. The recommended multidimensional measures facilitate the development of a comprehensive clinical picture. The objective measures help to further develop informative and novel insights into underlying pathophysiological mechanisms and illness trajectories to guide personalised care plans. A panel of specific multidimensional and objective measures are recommended as standard clinical practice, while others are recommended secondarily to provide deeper insights with the aim of revealing alternative clinical paths for targeted interventions and treatments matched to the clinical stage and proposed pathophysiological mechanisms of the young person. CHAPTER 4: PERSONALISING CARE OPTIONS IN YOUTH MENTAL HEALTH: USING MULTIDIMENSIONAL ASSESSMENT, CLINICAL STAGE, PATHOPHYSIOLOGICAL MECHANISMS, AND INDIVIDUAL ILLNESS TRAJECTORIES TO GUIDE TREATMENT SELECTION: New models of mental health care for young people require that interventions be matched to illness type, clinical stage, underlying pathophysiological mechanisms and individual illness trajectories. Narrow syndrome-focused classifications often direct clinical attention away from other key factors such as functional impairment, self-harm and suicidality, alcohol or other substance misuse, and poor physical health. By contrast, we outline a treatment selection guide for early intervention for adolescent-onset mood and psychotic syndromes (ie, active treatments and indicated and more specific secondary prevention strategies). This guide is based on experiences with the Brain and Mind Centre's highly personalised and measurement-based care model to manage youth mental health. The model incorporates three complementary core concepts: ▶A multidimensional assessment and outcomes framework including: social and occupational function; self-harm, suicidal thoughts and behaviours; alcohol or other substance misuse; physical health; and illness trajectory. ▶Clinical stage. ▶Three common illness subtypes (psychosis, anxious depression, bipolar spectrum) based on three underlying pathophysiological mechanisms (neurodevelopmental, hyperarousal, circadian). These core concepts are not mutually exclusive and together may facilitate improved outcomes through a clinical stage-appropriate and transdiagnostic framework that helps guide decisions regarding the provision of appropriate and effective care options. Given its emphasis on adolescent-onset mood and psychotic syndromes, the Brain and Mind Centre's model of care also respects a fundamental developmental perspective - categorising childhood problems (eg, anxiety and neurodevelopmental difficulties) as risk factors and respecting the fact that young people are in a period of major biological and social transition. Based on these factors, a range of social, psychological and pharmacological interventions are recommended, with an emphasis on balancing the personal benefit-to-cost ratio. CHAPTER 5: A SERVICE DELIVERY MODEL TO SUPPORT HIGHLY PERSONALISED AND MEASUREMENT-BASED CARE IN YOUTH MENTAL HEALTH: Over the past decade, we have seen a growing focus on creating mental health service delivery models that better meet the unique needs of young Australians. Recent policy directives from the Australian Government recommend the adoption of stepped-care services to improve the appropriateness of care, determined by severity of need. Here, we propose that a highly personalised approach enhances stepped-care models by incorporating clinical staging and a young person's current and multidimensional needs. It explicitly aims to prevent progression to more complex and severe forms of illness and is better aligned to contemporary models of the patterns of emergence of psychopathology. Inherent within a highly personalised approach is the incorporation of other evidence-based processes, including real-time measurement-based care and use of multidisciplinary teams of health professionals. Data-driven local system modelling and personalised health information technologies provide crucial infrastructure support to these processes for better access to, and higher quality of, mental health care for young people.

The course of neuropsychological functioning in young people with attenuated vs discrete mental disorders

AIM

Clinical staging of mental disorders is designed to facilitate the selection of stage-appropriate interventions, early in the course of illness. Neuropsychological performance, particularly at early stages of mental disorder, is a strong predictor of medium-term functional outcomes. Despite this, the longitudinal examination of neuropsychological profiles in early stages of illness is poorly researched. Thus, we examined baseline and longitudinal neuropsychological profiles of young patients with attenuated syndromes vs those with discrete disorders.

METHODS

Neuropsychological testing of 497 help-seeking young people (21.2 ± 3 years; 56% female). Clinical staging, assigned separately from testing, rated 262 individuals as "attenuated syndrome" (stage 1b) and 235 as "discrete" or "persistent" disorder (stage 2+). Follow-up testing was undertaken in 170 individuals (54% at stage 1b) after 19.8 ± 9 months (range: 3 to 51 months).

RESULTS

At baseline, attenuated and discrete/persistent disorders significantly differed in 4 of the 9 neuropsychological measures (verbal learning, verbal memory, visual memory and set shifting). Despite this, both groups showed similar improvement in neuropsychological functioning at follow-up, particularly in processing speed, sustained attention and visual memory. Longitudinal improvement in cognition corresponded with increases in socio-occupational functioning.

DISCUSSION

The degree of baseline neuropsychological dysfunction discriminates those with attenuated syndromes from those with a discrete/persistent disorder. Furthermore, improvement in neuropsychological functioning corresponded with improvement in clinical and functional status, despite stage of illness. This suggests that neuropsychological functioning remains relatively stable in young people with a mental illness and may be a critical window for intervention.

A case study of feedback and cognitive assessment of a young adult inpatient with major depressive disorder

OBJECTIVES

Neurocognitive assessment and feedback to a young adult inpatient.

METHODS

Computerised neurocognitive assessment and feedback.

RESULTS

A collaborative process of personalised intervention.

CONCLUSIONS

Personalised feedback in this setting can be employed as a management tool to identify and prioritise care.

Developing neurocognitive standard clinical care: A study of young adult inpatients

Neuropsychological assessments have provided the field of psychiatry with important information about patients. As an assessment tool, a neuropsychological battery can be useful in a clinical setting; however, implementation as standard clinical care in an inpatient unit has not been extensively evaluated. A computerized cognitive battery was administered to 103 current young adult inpatients (19.2 ± 3.1 years; 72% female) with affective disorder. Neurocognitive tasks included Verbal Recognition Memory (VRM), Attention Switching (AST), Paired Association Learning (PAL), and Rapid Visual Processing (RVP). Patients also completed a computerized self-report questionnaire evaluating subjective impressions of their cognition. Hierarchical cluster analysis determined three neurocognitive subgroups: cluster 1 (n = 17) showed a more impaired neurocognitive profile on three of the four variables compared to their peers in cluster 2 (n = 59), and cluster 3 (n = 27), who had the most impaired attentional shifting. Two of the four neurocognitive variables were significantly different between all three cluster groups (verbal learning and sustained attention). Overall group results showed an association between poorer sustained attention and increased suicidal ideation. These findings strengthen the idea that neurocognitive profiles may play an important role in better understanding the severity of illness in young inpatients with major psychiatric disorders.

Patterns of neuropsychological changes after general anaesthesia in young children: secondary analysis of the Mayo Anesthesia Safety in Kids study

BACKGROUND

We hypothesised that exposure to multiple, but not single, procedures requiring general anaesthesia before age 3 yr is associated with a specific pattern of deficits in processing speed and fine motor skills.

METHODS

A secondary analysis (using factor and cluster analyses) of data from the Mayo Anesthesia Safety in Kids study was conducted, in which unexposed, singly exposed, and multiply exposed children born in Olmsted County, MN, USA from 1994 to 2007 were sampled using a propensity-guided approach and underwent neuropsychological testing at ages 8-12 or 15-20 yr.

RESULTS

In the factor analysis, the data were well fit to a five factor model. For subjects multiply (but not singly) exposed to anaesthesia, a factor reflecting motor skills, visual-motor integration, and processing speed was significantly lower [standardised difference of -0.35 (95% confidence interval {CI} -0.57 to -0.13)] compared with unexposed subjects. No other factor was associated with exposure. Three groups were identified in the cluster analysis, with 106 subjects (10.6%) in Cluster A (lowest performance in most tests), 557 (55.9%) in Cluster B, and 334 (33.5%) in Cluster C (highest performance in most tests). The odds of multiply exposed children belonging to Cluster A was 2.83 (95% CI: 1.49-5.35; P=0.001) compared with belonging to Cluster B; there was no other significant association between exposure status and cluster membership.

CONCLUSIONS

Multiple, but not single, exposures to procedures requiring general anaesthesia before age 3 yr are associated with a specific pattern of deficits in neuropsychological tests. Factors predicting which children develop the most pronounced deficits remain unknown.

A data-driven transdiagnostic analysis of white matter integrity in young adults with major psychiatric disorders

Diffusion tensor imaging (DTI) has been utilized to index white matter (WM) integrity in the major psychiatric disorders. However, the findings within and across such disorders have been mixed. Given this, transdiagnostic sampling with data-driven statistical approaches may lead to new and better insights about the clinical and functional factors associated with WM abnormalities. Thus, we undertook a cross-sectional DTI study of 401 young adult (18-30 years old) outpatients with a major psychiatric (depressive, bipolar, psychotic, or anxiety) disorder and 61 healthy controls. Participants also completed self-report questionnaires and underwent neuropsychological assessment. Fractional anisotropy (FA) as well as axial (AD) and radial (RD) diffusivity was determined via a whole brain voxel-wise approach (tract-based spatial statistics). Hierarchical cluster analysis was performed on FA scores in patients only, obtained from 20 major WM tracts (that is, association, projection and commissural fibers). The three cluster groups derived were distinguished by having consistently increased or decreased FA scores across all tracts. Compared to controls, the largest cluster (N = 177) showed significantly increased FA in 55% of tracts, the second cluster (N = 169) demonstrated decreased FA (in 90% of tracts) and the final cluster (N = 55) exhibited the most increased FA (in 95% of tracts). Importantly, the distribution of primary diagnosis did not significantly differ among the three clusters. Furthermore, the clusters showed comparable functional, clinical and neuropsychological measures, with the exception of alcohol use, medication status and verbal fluency. Overall, this study provides evidence that among young adults with a major psychiatric disorder there are subgroups with either abnormally high or low FA and that either pattern is associated with suboptimal functioning. Importantly, these neuroimaging-based subgroups appear despite diagnostic and clinical factors, suggesting differential treatment strategies are warranted.

Performance on the Operant Test Battery in young children exposed to procedures requiring general anaesthesia: the MASK study

BACKGROUND

It is not known whether the neurotoxicity produced by anaesthetics administered to young animals can also occur in children. Exposure of infant macaques to ketamine impairs performance in selected domains of the Operant Test Battery (OTB), which can also be administered to children. This study determined whether a similar pattern of results on the OTB is found in children exposed to procedures requiring general anaesthesia before age 3 yr.

METHODS

We analysed data from the Mayo Anesthesia Safety in Kids (MASK) study, in which unexposed, singly-exposed, and multiply-exposed children born in Olmsted County, MN, USA, from 1994 to 2007 were sampled using a propensity-guided approach and prospectively underwent OTB testing at ages 8-12 or 15-20 yr, using five tasks that generated 15 OTB test scores.

RESULTS

In primary analysis, none of the OTB test scores depended upon anaesthesia exposure status when corrected for multiple comparisons. Cluster analysis identified four clusters of subjects, with cluster membership determined by relative performance on the OTB tasks. There was no evidence of association between exposure status and cluster membership. Exploratory factor analysis showed that the OTB scores loaded onto four factors. The score for one factor was significantly less in multiply-exposed children (mean standardised difference -0.28 [95% confidence interval, -0.55 to -0.01; P=0.04]), but significance did not survive a sensitivity analysis accounting for outlying values.

CONCLUSIONS

These findings provide little evidence to support the hypothesis that children exposed to procedures requiring anaesthesia show deficits on OTB tasks that are similar to those observed in non-human primates.

Neurocognitive clusters: A pilot study of young people with affective disorders in an inpatient facility

BACKGROUND

There is growing evidence to support the need for personalised intervention in the early stages of a major psychiatric illness, as well as the clear delineation of subgroups in psychiatric disorders based on cognitive impairment. Affective disorders are often accompanied by neurocognitive deficits; however a lack of research among young adult inpatients highlights the need to assess the utility of cognitive testing in this population.

METHODS

A computerised cognitive battery was administered to 50 current inpatient young adults (16-30 years; 75% female) with an affective disorder. Patients also completed a computerised self-report questionnaire (to measure demographics and clinical features) that included items evaluating subjective impressions of their cognition.

RESULTS

Hierarchical cluster analysis determined two neurocognitive subgroups: cluster 1 (n = 16) showed more severe impairments in sustained attention and memory as well as higher anxiety levels, compared to their peers in cluster 2 (n = 30) who showed the most impaired attentional switching. Across the sample, poor sustained attention was significantly correlated with higher levels of current anxiety and depressive symptoms, whereas poor verbal memory was significantly associated with increased psychological distress.

LIMITATIONS

This study has a relatively small sample size (due to it being a pilot/feasibility study). Furthermore, future studies should aim to assess inpatient samples compared to community care samples, as well as healthy controls, on a larger scale.

CONCLUSIONS

The findings suggest neurocognitive profiles are important in understanding phenotypes within young people with severe affective disorders. With clear subgroups based on cognitive impairment being demonstrated, the clinical utility and use of new and emerging technologies is warranted in such inpatients facilities. This pilot/feasibility study has strengthened the utility of cognitive screening as standard clinical care in an inpatient unit.

Parcellating cognitive heterogeneity in early psychosis-spectrum illnesses: A cluster analysis

Cognitive impairment is argued to represent a core feature of psychosis-spectrum illnesses. However, within-diagnosis heterogeneity is common, and risk factors for poor cognition remain to be examined after statistically accounting for heterogeneity. Accordingly, we used a data-driven technique (cluster analysis) to empirically-derive cognitive clusters across diagnoses and examined whether concurrent substance use or a history of a neurodevelopmental/behavioral disorder differed between clusters. Data from 135 young help-seekers (aged 12-30 years) with a psychosis-spectrum illness were retrospectively analyzed. Ward's hierarchical cluster analysis classified three cognitive clusters characterized by: (1) normal-range; (2) mixed; and (3) grossly-impaired performance. Despite mostly comparable clinical and demographic measures, cluster 1 had superior socio-occupational functioning and the highest estimated premorbid IQ, followed sequentially by clusters 2 and 3. Proportions of cannabis and amphetamine users did not differ significantly across clusters, nor did rates of patients with a neurodevelopmental/behavioral disorder history. Cluster 3 was however comprised of fewer 'risky' drinkers, possibly reflecting reduced opportunity for social drinking associated with cognitive impairment. Estimated premorbid IQ predicted cluster membership (2 vs. 1 & 3 vs. 1), as did clinician-rated socio-occupational functioning and 'not being enrolled in school or tertiary education' (3 vs. 1). Our results suggest that concurrent substance use and history of a neurodevelopmental/behavioral disorder do not adequately explain cluster-level cognitive variance in this sample. Future work should integrate neurobiological measures associated with cognition (e.g. white matter integrity) to discern whether clusters reflect neurobiological subtypes better representative of pathophysiology than present symptom-based classifications.

The relationship between depression and cognitive function in adults with cardiovascular risk: Evidence from a randomised attention-controlled trial

Background and aim

This study assessed the association between depressive symptom severity and cognition in middle-to-older aged adults with mild-to-moderate depression and cardiovascular risk factors using an online test battery (CogState) and whether changes in depressive symptoms over 3 months were associated with changes in cognition.

Methods

Participants (mean age = 57.8) with cardiovascular risk and mild–to-moderate depressive symptoms completed measures of psychomotor speed, learning, and executive function prior to (n = 445)_and after (n = 334) online depression or attention control interventions. The symptom severity-cognition relationship was examined both cross-sectionally and prospectively.

Results

Participants exhibited significantly reduced psychomotor speed and variable impairments on measures of learning and executive functioning relative to normative data. However, there was no association of depression severity with cognition at baseline or of change in depressive symptoms with change in cognitive performance.

Limitations

Participants were well-educated, which may have protected against cognitive decline. Attrition may limit generalisability, though is unlikely to explain the lack of association between depression symptoms and cognition.

Conclusions

Adults with comorbid mild-to-moderate depressive symptoms and cardiovascular risks performed less well than age-matched normative data on three online cognitive tests; however, we were unable to show any symptom-cognition association cross-sectionally or longitudinally, despite significant improvements in depressive symptoms. This challenges the generalisability of such associations found in more severely unwell clinical samples to those with a broader depressive symptom profile, or suggests that underlying cardiovascular disease may account for the association seen in some clinical studies. This has implications for scaling up selective prevention of cognitive decline.

Cognitive predictors of illness course at 12 months after first-episode of depression

Major Depressive Disorder (MDD) entails cognitive dysfunction in many cognitive domains, but it is still uncertain whether such deficits are present in the early stages. The purpose of the study is to determine the cognitive performance in first episode depression (FED) exploring the presence of different cognitive profiles, and the role of cognition in FED at baseline and long-term. Ninety subjects (18-50 years) were included, 50 patients with a FED and 40 healthy controls. Participants were assessed with a neuropsychological battery, covering language, attention, verbal memory, processing speed and executive domains. Neuropsychological group comparisons were performed with MANOVAs. A hierarchical cluster analysis was run to identify clusters of patients with similar neuropsychological performance. Two generalized linear models were built to predict baseline HDRS-17 and changes at 12 months. Patients performed significantly worse than healthy controls in language, attention/working memory, verbal memory, processing speed and executive functioning, with moderate to large effect sizes (0.5 - 1). Two clusters were found: cognitively preserved patients (n=37) and cognitively impaired patients (n=13). Large effect sizes of cognitive impairment in FED were observed between the two cognitive clusters (preserved and impaired). Depressive symptoms at baseline were predicted by verbal memory (p=0.003), while 12-month changes were predicted by executive function (p=0.041) and language (p=0.037). Cognitive performance predicted depressive symptoms at baseline and at follow-up, pointing to the usefulness of cognitive assessment even at the commencement of the illness.

Everyday false memories in older persons with depressive disorder

Generally we tend to think that memory in daily living is complete and accurate in healthy persons. However, current memory research has revealed inconspicuous memory faults. Rarely omissions and distortions of memory are researched with tasks resembling everyday life. We investigated healthy older control subjects (HC) and patients with depressive disorder (DD). Cognitive function was assessed with a comprehensive neuropsychological test battery and mood with the Montgomery-Asberg Depression Scale (MADRS). We assessed everyday veridical and distorted memories on showing participants original news and commercials. In most aspects of attention, executive functions, and memory, patients with DD performed worse than HC. Regarding memory content on viewing news or commercials the difference between patients with DD and HC was more pronounced for false memory content than for veridical memory content. Linear regression analysis showed the extent of false memory content being associated with mental flexibility as assessed with the Trail Making Test and mood as assessed with the MADRS for both information obtained on viewing news and commercials. Increase of false memories impedes overall accuracy of memory more than decrease of veridical memories in older persons with depressive disorder. Diminished executive functions and depressive mood partly explain these memory distortions.

Subcortical volumetric differences between clinical stages of young people with affective and psychotic disorders

The aim of this study was to investigate differences in subcortical and hippocampal volumes between healthy controls, young people at an early stage of affective and psychotic disorders and those in more advanced stages, to identify markers associated with functional outcomes and illness severity. Young people presenting to youth mental health services with admixtures of depressive, manic and psychotic symptoms (n = 141), and healthy counterparts (n = 49), aged 18-25 were recruited. Participants underwent magnetic resonance imaging, clinical assessments and were rated as to their current clinical stage. Eighty-four patients were classified at the attenuated syndrome stage (Stage 1b) and 57 were classified as having discrete and persistent disorders (Stage 2+). Automated segmentation was performed using NeuroQuant® to determine volumes of subcortical and hippocampus structures which were compared between groups and correlated with clinical and functional outcomes. Compared to healthy controls, Stage 2+ patients showed significantly reduced right amygdala volumes. Whereas Stage 1b patients showed significantly reduced left caudate volumes compared to healthy controls. Smaller left caudate volume correlated with greater psychological distress and impaired functioning. This study shows a clinical application for an automated program to identify and track subcortical changes evident in young people with emerging psychopathology.

Neuropsychological Clustering in Bipolar and Major Depressive Disorder

OBJECTIVES

Cognitive dysfunction is a key feature of major depressive (MDD) and bipolar (BD) disorders. However, rather than a single cognitive profile corresponding to each diagnostic categories, recent studies have identified significant intra- and cross-diagnostic variability in patterns of cognitive impairment. The goal of this study was to contribute to the literature on cognitive heterogeneity in mood disorders by identifying cognitive subprofiles in a population of patients with MDD, BD type I, BD type II, and healthy adults.

METHODS

Participants completed a neuropsychological battery; scores were converted into Z-scores using normative data and submitted to hierarchical cluster analysis.

RESULTS

Three distinct neuropsychological clusters were identified: (1) a large cluster containing mostly control participants, as well as some patients with BD and MDD, who performed at above-average levels on all neuropsychological domains; (2) a cluster containing some patients from all diagnostic groups, as well as healthy controls, who performed worse than cluster 1 on most tasks, and showed impairments in motor inhibition and verbal fluency; (3) a cluster containing mostly patients with mood disorders with severe impairments in verbal inhibition and cognitive flexibility.

CONCLUSIONS

These findings revealed multiple cognitive profiles within diagnostic categories, as well as significant cross-diagnostic overlap, highlighting the importance of developing more specific treatment approaches which consider patients' demographic and cognitive profiles in addition to their diagnosis. (JINS, 2017, 23, 584-593).

Advancing Symptom Science Through Symptom Cluster Research: Expert Panel Proceedings and Recommendations

An overview of proceedings, findings, and recommendations from the workshop on "Advancing Symptom Science Through Symptom Cluster Research" sponsored by the National Institute of Nursing Research (NINR) and the Office of Rare Diseases Research, National Center for Advancing Translational Sciences, is presented. This workshop engaged an expert panel in an evidenced-based discussion regarding the state of the science of symptom clusters in chronic conditions including cancer and other rare diseases. An interdisciplinary working group from the extramural research community representing nursing, medicine, oncology, psychology, and bioinformatics was convened at the National Institutes of Health. Based on expertise, members were divided into teams to address key areas: defining characteristics of symptom clusters, priority symptom clusters and underlying mechanisms, measurement issues, targeted interventions, and new analytic strategies. For each area, the evidence was synthesized, limitations and gaps identified, and recommendations for future research delineated. The majority of findings in each area were from studies of oncology patients. However, increasing evidence suggests that symptom clusters occur in patients with other chronic conditions (eg, pulmonary, cardiac, and end-stage renal disease). Nonetheless, symptom cluster research is extremely limited and scientists are just beginning to understand how to investigate symptom clusters by developing frameworks and new methods and approaches. With a focus on personalized care, an understanding of individual susceptibility to symptoms and whether a "driving" symptom exists that triggers other symptoms in the cluster is needed. Also, research aimed at identifying the mechanisms that underlie symptom clusters is essential to developing targeted interventions.

Identification and individualized prediction of clinical phenotypes in bipolar disorders using neurocognitive data, neuroimaging scans and machine learning

Diagnosis, clinical management and research of psychiatric disorders remain subjective - largely guided by historically developed categories which may not effectively capture underlying pathophysiological mechanisms of dysfunction. Here, we report a novel approach of identifying and validating distinct and biologically meaningful clinical phenotypes of bipolar disorders using both unsupervised and supervised machine learning techniques. First, neurocognitive data were analyzed using an unsupervised machine learning approach and two distinct clinical phenotypes identified namely; phenotype I and phenotype II. Second, diffusion weighted imaging scans were pre-processed using the tract-based spatial statistics (TBSS) method and 'skeletonized' white matter fractional anisotropy (FA) and mean diffusivity (MD) maps extracted. The 'skeletonized' white matter FA and MD maps were entered into the Elastic Net machine learning algorithm to distinguish individual subjects' phenotypic labels (e.g. phenotype I vs. phenotype II). This calculation was performed to ascertain whether the identified clinical phenotypes were biologically distinct. Original neurocognitive measurements distinguished individual subjects' phenotypic labels with 94% accuracy (sensitivity=92%, specificity=97%). TBSS derived FA and MD measurements predicted individual subjects' phenotypic labels with 76% and 65% accuracy respectively. In addition, individual subjects belonging to phenotypes I and II were distinguished from healthy controls with 57% and 92% accuracy respectively. Neurocognitive task variables identified as most relevant in distinguishing phenotypic labels included; Affective Go/No-Go (AGN), Cambridge Gambling Task (CGT) coupled with inferior fronto-occipital fasciculus and callosal white matter pathways. These results suggest that there may exist two biologically distinct clinical phenotypes in bipolar disorders which can be identified from healthy controls with high accuracy and at an individual subject level. We suggest a strong clinical utility of the proposed approach in defining and validating biologically meaningful and less heterogeneous clinical sub-phenotypes of major psychiatric disorders.

Similarities and Differences of Neuropsychological Profiles in Children and Adolescents with Anorexia Nervosa and Healthy Controls Using Cluster and Discriminant Function Analyses

OBJECTIVE

This study aimed to identify discrete neuropsychological profiles and their relationship to clinical symptoms in 253 female children and adolescents with anorexia nervosa (AN) and 170 healthy controls (HCs) using a standardised neuropsychological assessment battery.

METHOD

Hierarchical cluster analysis was used to identify the optimum number of clusters, and participants were assigned using K-means cluster analysis. Confirmatory discriminant function analysis determined which combination of neuropsychological variables best distinguished the clusters.

RESULTS

Three distinct clusters in the AN sample emerged- AN cluster 1 (19%) - "neuropsychologically low average to average"; AN cluster 2 (33%) - "verbal/visuo-spatial discrepancy"; and AN cluster 3 (48%) - "verbally strong and neuropsychologically average to high average". Two distinct clusters in HCs were identified. HC cluster 1 (48%) demonstrated poor visuo-spatial memory scores and high verbal fluency scores, whilst HC cluster 2 (52%) scored within the average range on all neuropsychological tasks. Neuropsychological performance was associated with clinical symptoms of body mass index centile, Eating Disorder Examination subscale and global score, anxiety, depression and obsessions, and compulsions between the AN and HC groups. However, niether significant differences emerged between AN clusters only nor HC clusters only at the post-hoc level.

DISCUSSION

An underlying neuropsychological heterogeneity may exist in AN. We encourage future studies to investigate whether the identified profiles and their association with clinical characteristics are replicable. We cautiously suggest that neuropsychological profiling may have potential to both inform future research and have possible clinical benefits through individually tailored treatment strategies.

Clusters of Insomnia Disorder: An Exploratory Cluster Analysis of Objective Sleep Parameters Reveals Differences in Neurocognitive Functioning, Quantitative EEG, and Heart Rate Variability

STUDY OBJECTIVES

To empirically derive and evaluate potential clusters of Insomnia Disorder through cluster analysis from polysomnography (PSG). We hypothesized that clusters would differ on neurocognitive performance, sleep-onset measures of quantitative (q)-EEG and heart rate variability (HRV).

METHODS

Research volunteers with Insomnia Disorder (DSM-5) completed a neurocognitive assessment and overnight PSG measures of total sleep time (TST), wake time after sleep onset (WASO), and sleep onset latency (SOL) were used to determine clusters.

RESULTS

From 96 volunteers with Insomnia Disorder, cluster analysis derived at least two clusters from objective sleep parameters: Insomnia with normal objective sleep duration (I-NSD: n = 53) and Insomnia with short sleep duration (I-SSD: n = 43). At sleep onset, differences in HRV between I-NSD and I-SSD clusters suggest attenuated parasympathetic activity in I-SSD (P < 0.05). Preliminary work suggested three clusters by retaining the I-NSD and splitting the I-SSD cluster into two: I-SSD A (n = 29): defined by high WASO and I-SSD B (n = 14): a second I-SSD cluster with high SOL and medium WASO. The I-SSD B cluster performed worse than I-SSD A and I-NSD for sustained attention (P ≤ 0.05). In an exploratory analysis, q-EEG revealed reduced spectral power also in I-SSD B before (Delta, Alpha, Beta-1) and after sleep-onset (Beta-2) compared to I-SSD A and I-NSD (P ≤ 0.05).

CONCLUSIONS

Two insomnia clusters derived from cluster analysis differ in sleep onset HRV. Preliminary data suggest evidence for three clusters in insomnia with differences for sustained attention and sleep-onset q-EEG.

CLINICAL TRIAL REGISTRATION

Insomnia 100 sleep study: Australia New Zealand Clinical Trials Registry (ANZCTR) identification number 12612000049875. URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=347742.

Neurocognitive Phenotypes in Severe Childhood Psychiatric Disorders

This study investigated the presence of potential neurocognitive phenotypes within a severe childhood psychiatric sample. A medical chart review was conducted for 106 children who received a neuropsychological evaluation during children's psychiatric inpatient program hospitalization. A hierarchical cluster analysis was conducted to identify distinct clinical clusters based on neurocognitive measures. Cluster analysis identified four distinct clusters, subsequently labeled neurocognitive phenotypes: "intact cognition" (27%), "global dysfunction" (20%), "organization/planning" (21%), and "inhibition-memory" (32%). Significant differences were identified in history of legal involvement and antipsychotic medications at hospital admission. Differences between none-minimal and moderate-high neurocognitive dysfunction were identified in age, amount of diagnoses and antipsychotic medications at admission, and hospital length of stay. Current findings provide preliminary evidence of underlying neurocognitive phenotypes within severe childhood psychiatric disorders. Findings highlight the importance of neuropsychological evaluation in the treatment of childhood psychiatric disorders.

Quality of life, functioning and cognition in bipolar disorder and major depression: A latent profile analysis

This study aimed to identify profiles of functioning and quality of life (QOL) in depression (MDD), bipolar disorder (BD) and healthy adults, as well as the clinical, demographic and cognitive variables associated with each of these profiles. Participants completed the WHODAS 2.0 and WHOQOL-BREF, which were submitted to latent profile analysis. The four cluster solution provided the best fit for our data. Cluster 1 consisted mostly of healthy adults, and had the highest functioning and QOL. Clusters 2 contained older patients with subclinical depressive symptoms and psychiatric comorbidities, whose impairments in QOL and functioning were associated with mood symptoms and several cognitive abilities. Patients with MDD, BDI or BDII with mild to moderate depression, such as those in cluster 3, may benefit more significantly from interventions in cognitive flexibility, inhibition, planning, and sustained attention. Lastly, patients with mood disorders and clinically significant levels of depression, as well as a history of suicide attempts, like those in cluster 4, may benefit from interventions aimed at working memory, inhibitory control, and cognitive flexibility; that is, the three core executive functions. These findings should be further investigated, and used to guide treatments for patients with mood disorders and different patterns of functional impairment.

Impaired causal awareness and associated cortical-basal ganglia structural changes in youth psychiatric disorders

Background

Cognitive impairments contribute significantly to disease burden in young individuals presenting with major psychiatric disorders. The capacity to encode the consequences of one's actions may be of particular importance for real-world functioning due to its fundamental role in goal-directed behavior.

Methods

Here, we investigated a dimensional measure of causal awareness during a probabilistic learning task in 92 young individuals with an admixture of major mood and psychotic illnesses, at early and more established stages. Using automated gray matter segmentation of T1-weighted images, we estimated the volume and shapes of major subcortical structures and investigated their association with causal awareness.

Results

The low causal awareness (LCA) group (n = 35) reported increased social disability (p = .004) and reduced right pallidal size, specifically within the dorsolateral surfaces (p = .02), relative to the unimpaired high causal awareness (HCA) patients (n = 57). In early-stage illness, LCA had a smaller right thalamus (p = .002) relative to HCA. Exploratory investigations suggested that in developed psychotic syndromes, causal awareness was correlated with left hippocampal size (p = .006) whereas, in more persistent affective disorders, causal awareness was correlated with left amygdala size (p = .013), specifically within the anterior aspect.

Discussion

Low causal awareness occurs across diagnoses and stages of illness and is associated with poor functional outcomes. Our results suggest that there may be shared neural underpinnings of its dysfunction in the early course of mood and psychotic disorders, however in more established illness, there is greater neurobiological divergence in causal awareness correlates between diagnoses.

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Impaired awareness of causal relationships occurs trans-diagnostically.

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Participants with low causal awareness have poorer functional outcomes.

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Low causal awareness was associated with reduced right pallidal size

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Low causal awareness was associated with a lateralized limbic-pallidal circuit.

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Results suggest common neural dysfunction in early mood and psychotic disorders.

Treatment patterns and short-term outcomes in an early intervention youth mental health service

AIM

Early intervention mental health services tailored for young people are being developed across the world, yet reports on service use patterns and short-term clinical outcomes for the clinically diverse group accessing these services are very limited. The current study employed the clinical staging model to examine whether young people within the two clinical stages that precede full-threshold disorder (stage 1a and stage 1b) differed in terms of treatments received and short-term symptomatic and functional outcomes.

METHODS

Eight hundred ninety young people aged 12-25 years seeking mental healthcare within a 12-month period were analysed in this study.

RESULTS

Attenuated syndrome (stage 1b) patients used significantly more services than help-seeking (stage 1a) patients, including significantly higher rates of psychotropic medication prescription (9.3% vs. 43.6%). Stage 1a patients started with significantly lower levels of psychological distress and significantly higher levels of functioning at service entry and showed improvement only in psychological distress over 10 sessions. Despite using significantly more services, stage 1b patients remained impaired on both measures after 10 sessions; however, they showed some modest improvements in their levels of psychological distress and functioning over this time.

CONCLUSION

Patients with attenuated syndromes have treatment patterns and clinical outcomes not dissimilar to those with more severe mental disorders and therefore require more intensive interventions provided over a longer time period in order to achieve recovery. The staging model allows services to selectively allocate their limited resources towards those patients with greater care needs. More research into the unique treatment needs and longer term outcomes of this diverse patient group is supported.

Cognitive dysfunction and functional disability in alcohol-dependent adults with or without a comorbid affective disorder

INTRODUCTION

Little is known about the relationship between cognitive dysfunction and functional disability in alcohol dependence with comorbid affective disorders. We investigated the neuropsychology of alcohol dependence in detoxified adults with and without affective comorbidity and examined the factors associated with prolonged functional disability.

METHODS

From a total of 42 participants (age range = 18-44 years), 12 out of 21 alcohol-dependent participants had a comorbid affective disorder, 12 had an affective disorder only, and 9 were healthy controls. Participants completed a semi-structured clinical interview, questionnaires and comprehensive neuropsychological assessment.

RESULTS

Following detoxification (median = 35 days; M = 41.2 days, SD = 17.9), visual learning and memory functioning was worse in alcohol-dependent individuals. Comorbid affective disorders did not appear to exacerbate cognitive dysfunction. Psychiatric comorbidity and current depressive symptoms were predictive of poorer functional disability. Furthermore, learning and memory, and response inhibition, contributed significantly and independently to predicting functional disability over and above clinical and demographic factors.

CONCLUSIONS

Psychiatric comorbidity does not appear to be associated with more pronounced neuropsychological dysfunction in alcohol dependence. Conversely, both comorbid affective disorders and cognitive factors were critical in determining the functional outcomes of alcohol-dependent adults recently undergoing medically supervised inpatient detoxification.

Hippocampal glutamatergic/NMDA receptor functioning in bipolar disorder: A study combining mismatch negativity and proton magnetic resonance spectroscopy

Disturbances in the hippocampal glutamate (Glu)/N-methyl-d-aspartate (NMDA) system have been implicated in the pathophysiology of bipolar disorder (BD). Here we aim to provide a targeted integration of two measures of glutamatergic functioning in BD; the association between mismatch negativity (MMN) and in vivo hippocampal-Glu measured via proton magnetic resonance spectroscopy ((1)H MRS). Participants comprised of 33 patients with BD and 23 matched controls who underwent a two-tone passive, duration deviant MMN paradigm and (1)H MRS. Levels of Glu/creatine (Cr) in the hippocampus were determined. Pearson's correlations were used to determine associations between MMN and Glu/Cr. In controls, MMN amplitude was positively associated with Glu/Cr at the left temporal site. We did not find any significant associations with Glu/Cr and frontocentral MMN nor did we find any significant associations in BD patients. The results provide further insight into the neurophysiology of MMN, with evidence supporting the role of hippocampal-Glu signalling through the NMDA receptor in temporal MMN. Our data also demonstrate that Glu/Cr regulation of MMN is dampened in BD, which may indicate a lack of tightly regulated hippocampal NMDA functioning. These findings provide insight into the underlying basis of glutamatergic transmission disturbances implicated in the disorder.

Cluster analysis reveals abnormal hippocampal neurometabolic profiles in young people with mood disorders

While numerous studies have employed magnetic resonance spectroscopy (MRS) to determine in vivo neurometabolite levels associated with mood disorders the findings in both unipolar depression and bipolar disorder have been mixed. Data-driven studies may shed new light on this literature by identifying distinct subgroups of patients who may benefit from different treatment strategies. The objective of the present study was to utilize hierarchical cluster analysis in order to generate new hypotheses with respect to neurometabolic profiling of mood disorder. Participants were 165 young persons (18-30 yrs) with a mood disorder and 40 healthy controls. Neurometabolite levels were recorded via proton-MRS ((1)H MRS). The ratios (relative to creatine) of glutamate (GLU), N-acetyl aspartate (NAA) and myo-inositol (MI) measured within the hippocampus. Self-reported and clinician rated symptoms as well as cognition were also measured. The unipolar depression (N=90) and bipolar disorder (N=75) groups did not significantly differ (from each other or controls) in their levels of GLU, NAA or MI. Cluster analyses derived four subgroups of patients who were distinguished by all three metabolites. There was a pattern of positive association between NAA and GLU, whereby clusters were abnormally increased (clusters 1, 2) or normal (cluster 4) or abnormally decreased (cluster 3) in these neurometabolites. These findings suggest that there are neurometabolic abnormalities in subgroups of young people with mood disorder, which may occur despite diagnostic similarities. Such evidence highlights that the underlying neurobiology of mood disorder is complex and MRS may have unique utility in delineating underlying neurobiology and targeting treatment strategies.

Neuropsychological and functional outcomes in recent-onset major depression, bipolar disorder and schizophrenia-spectrum disorders: a longitudinal cohort study

Functional disability is the lead contributor to burden of mental illness. Cognitive deficits frequently limit functional recovery, although whether changes in cognition and disability are longitudinally associated in recent-onset individuals remains unclear. Using a prospective, cohort design, 311 patients were recruited and assessed at baseline. One hundred and sixty-seven patients met eligibility criteria (M=21.5 years old, s.d.=4.8) and returned for follow-up (M=20.6 months later, s.d.=7.8). Two-hundred and thirty participants were included in the final analysis, comprising clinically stable patients with major depression (n=71), bipolar disorder (BD; n=61), schizophrenia-spectrum disorders (n=35) and 63 healthy controls. Neuropsychological functioning and self-rated functional disability were examined using mixed-design, repeated-measures analysis, across diagnoses and cognitive clusters, covarying for relevant confounds. Clinical, neuropsychological and functional changes did not differ between diagnoses (all P>0.05). Three reliable neuropsychological subgroups emerged through cluster analysis, characterized by psychomotor slowing, improved sustained attention, and improved verbal memory. Controlling for diagnosis and changes in residual symptoms, clusters with improved neuropsychological functioning observed greater reductions in functional disability than the psychomotor slowing cluster, which instead demonstrated a worsening in disability (P<0.01). Improved sustained attention was independently associated with greater likelihood of follow-up employment (P<0.01). Diagnosis of BD uniquely predicted both follow-up employment and independent living. Neuropsychological course appears to be independently predictive of subjective and objective functional outcomes. Importantly, cognitive phenotypes may reflect distinct pathophysiologies shared across major psychiatric conditions, and be ideal targets for personalized early intervention.

A longitudinal proton magnetic resonance spectroscopy study investigating oxidative stress as a result of alcohol and tobacco use in youth with bipolar disorder

Alcohol and tobacco have been suggested to be "aggravating factors" for neuroprogression in bipolar disorder (BD), however the impact of these substances on the underlying neurobiology is limited. Oxidative stress is a key target for research into neuroprogression in BD and in accordance with this model, our previous cross-sectional studies have found that risky alcohol and tobacco use in BD is associated with increased oxidative stress, investigated via in vivo glutathione (GSH) measured by proton magnetic resonance spectroscopy ((1)H-MRS) in the anterior cingulate cortex (ACC). What remains unknown is whether the negative impact on GSH levels can be modified as a result of limiting alcohol and tobacco use. Thirty BD patients were included in the study. (1)H-MRS and tobacco and alcohol measures were conducted at baseline and follow-up assessments (15.5±4.6 months apart). Pearson׳s correlations were performed between percentage change in GSH concentration and changes in alcohol/tobacco use. Regression analyses were then conducted to further explore the significant correlations. An increase in GSH was associated with a decrease in alcohol consumption (r=-0.381, p<0.05) and frequency of tobacco use (-0.367, p=0.05). Change in alcohol consumption, tobacco use and age were significant predictors of change in GSH concentration (F (3, 26)=3.69, p<0.05). Due to the high comorbidity of alcohol and tobacco use in the sample, the individual effects of these substances on GSH levels could not be determined. This study offers longitudinal evidence that changing risky drinking patterns and tobacco use early in the course of BD is associated with improvements in antioxidant capacity, and therefore may be specific targets for early intervention and prevention of neuroprogression in BD.

The N-methyl-D-aspartate receptor as a neurobiological intersection between bipolar disorder and alcohol use: a longitudinal mismatch negativity study

BACKGROUND

Comorbid risky alcohol use in bipolar disorder (BD) is recognized for its high prevalence and clinical relevance, though understanding of its neurobiological underpinning is limited. The N-methyl-D-aspartate (NMDA) receptor has recognized alterations in BD and is a major site of ethanol's effects in the brain. The present study aimed to examine the NMDA receptor system in adolescents and young adults with BD by evaluating the longitudinal changes in a robust marker of NMDA function, mismatch negativity (MMN), in relation to changes in alcohol use patterns.

METHODS

Forty-six BD patients (aged 16-30) were recruited at baseline and 59% (n = 27) returned for follow-up 17.9 +/- 7.3 months later. At both time-points a two-tone, passive, duration-deviant MMN paradigm was conducted and alcohol measures were collected. Pearson's correlations were performed between changes in MMN amplitudes and changes in alcohol use. Multiple regression was used to assess whether MMN amplitudes at baseline could predict alcohol use at follow-up.

RESULTS

Reduction in risky drinking patterns was associated with increased temporal MMN and decreased fronto-central MMN. Larger temporal MMN at baseline was a significant predictor of greater alcohol use at follow-up.

CONCLUSIONS

Results suggest risky alcohol use in BD may further compound pre-existing NMDA receptor abnormalities and, importantly, reducing alcohol use early in stages of illness is associated with changes in MMN. This highlights the importance of monitoring alcohol use from first presentation. In addition, preliminary results present an exciting potential for utility of MMN as a neurobiological marker used to determine risk for alcohol misuse in BD.

Neuro- and social-cognitive clustering highlights distinct profiles in adults with anorexia nervosa

OBJECTIVE

This study aimed to explore the neuro- and social-cognitive profile of a consecutive series of adult outpatients with anorexia nervosa (AN) when compared with widely available age and gender matched historical control data. The relationship between performance profiles, clinical characteristics, service utilization, and treatment adherence was also investigated.

METHOD

Consecutively recruited outpatients with a broad diagnosis of AN (restricting subtype AN-R: n = 44, binge-purge subtype AN-BP: n = 33 or Eating Disorder Not Otherwise Specified-AN subtype EDNOS-AN: n = 23) completed a comprehensive set of neurocognitive (set-shifting, central coherence) and social-cognitive measures (Emotional Theory of Mind). Data were subjected to hierarchical cluster analysis and a discriminant function analysis.

RESULTS

Three separate, meaningful clusters emerged. Cluster 1 (n = 45) showed overall average to high average neuro- and social- cognitive performance, Cluster 2 (n = 38) showed mixed performance characterized by distinct strengths and weaknesses, and Cluster 3 (n = 17) showed poor overall performance (Autism Spectrum disorder (ASD) like cluster). The three clusters did not differ in terms of eating disorder symptoms, comorbid features or service utilization and treatment adherence. A discriminant function analysis confirmed that the clusters were best characterized by performance in perseveration and set-shifting measures.

DISCUSSION

The findings suggest that considerable neuro- and social-cognitive heterogeneity exists in patients with AN, with a subset showing ASD-like features. The value of this method of profiling in predicting longer term patient outcomes and in guiding development of etiologically targeted treatments remains to be seen.