Adjunctive methylphenidate extended release in patients with schizophrenia: Protocol of a single-centre fixed dose cross-over open-label trial to improve functional and cognitive outcomes

Background

Cognitive symptoms, among the core symptoms of schizophrenia, are associated with poor functional outcome and burden of illness. To date, there is no effective pharmacological treatment for these symptom clusters. Augmentation with psychostimulants has been proposed as a potential treatment option.

Objectives

The present study aims to assess off-label use of adjunctive methylphenidate extended release (ER) in patients with schizophrenia who are stable on antipsychotic medications, and to assess its efficacy on functioning and cognitive outcome.

Methods

This is a single centre study at the Royal Ottawa Mental Health Centre. An open-label fixed dose controlled cross-over trial is planned. Eligible participants will be randomized into one of two arms of the study: 1) four weeks of add-on methylphenidate ER 36 mg, or 2) four weeks of treatment as usual. At 4 weeks, participants will switch arms. The duration of the study includes 8 weeks of treatment and a follow-up visit at 12 weeks. Primary outcome measures include tablet-based tests of functioning and cognition (VRFCAT and BAC) and will be administered at baseline and every 4 weeks. We are aiming to recruit a total of 24 participants.

Expected outcomes

The proposed project intends to assess a potential treatment option for cognitive deficits of schizophrenia, for which there are no recommendations by current treatment guidelines. The novelty and significance of the current study is that it investigates this intervention and assess applicability of it in a "real world setting" in a tertiary care hospital.

Consistency of Delusion Themes Across First and Subsequent Episodes of Psychosis

Importance

Despite growing interest in the phenomenology of delusions in psychosis, at present little is known about their content and evolution over time, including whether delusion themes are consistent across episodes.

Objective

To examine the course of delusions and thematic delusion content across relapse episodes in patients presenting to an early intervention service for psychosis.

Design, Setting, and Participants

This longitudinal, observational study used clinical data systematically collected from January 2003 to March 2018 from a cohort of consenting patients with affective or nonaffective first-episode psychosis, followed up naturalistically for up to 2 years in an early intervention service for psychosis in Montréal, Quebec, Canada. Data included the thematic content and severity of delusions (scores ≥3 using the Scale for the Assessment of Positive Symptoms) and associated psychotic and nonpsychotic symptoms, both across an initial episode and, in the event of remission, a potential relapse. Data were analyzed from September 2021 to February 2023.

Exposure

An early intervention service for psychosis, organized around intensive case management and a multidisciplinary team approach, which observed each patient for up to 2 years of care.

Main Outcomes and Measures

The primary outcome was positive symptom relapse and remission, including the presence and content of delusions, which was coded per the Scale for the Assessment of Positive Symptoms and accepted definitions. The main statistical measures included repeated paired-sample t tests and binary logistic regression analyses.

Results

Of 636 consenting patients, mean (SD) age was 23.8 (4.75) years; 191 patients were female, 444 were male, and 1 patient was nonbinary. Remission rates were high, and relapse rates were relatively low: 591 individuals had baseline delusions, of which 558 (94.4%) achieved remission. Of these 558 patients, only 182 (32.6%) had a subsequent relapse to a second or later episode of psychosis. Of the 182 patients who did relapse, however, a large proportion (115 [63.2%]) reported threshold-level delusions. Of these 115, 104 patients (90.4%) had thematic delusion content consistent with that reported during the index (first) episode. Those who relapsed with delusions had fewer delusion themes present during subsequent episodes of psychosis compared with the index episode and lower levels of other psychotic and nonpsychotic symptoms.

Conclusions and Relevance

Specialized early intervention services for psychosis can achieve high rates of sustained remission. However, in this study, the minority of individuals with delusions who later relapsed experienced similar delusion themes during subsequent episodes. These findings raise important considerations for the conceptualization of delusions and have clinical implications for trajectories of illness and care.

Longitudinal inference of multiscale markers in psychosis: from hippocampal centrality to functional outcome

Multiscale neuroscience conceptualizes mental illness as arising from aberrant interactions across and within multiple biopsychosocial scales. We leverage this framework to propose a multiscale disease progression model of psychosis, in which hippocampal-cortical dysconnectivity precedes impairments in episodic memory and social cognition, which lead to more severe negative symptoms and lower functional outcome. As psychosis represents a heterogeneous collection of biological and behavioral alterations that evolve over time, we further predict this disease progression for a subtype of the patient sample, with other patients showing normal-range performance on all variables. We sampled data from two cross-sectional datasets of first- and multi-episode psychosis, resulting in a sample of 163 patients and 119 non-clinical controls. To address our proposed disease progression model and evaluate potential heterogeneity, we applied a machine-learning algorithm, SuStaIn, to the patient data. SuStaIn uniquely integrates clustering and disease progression modeling and identified three patient subtypes. Subtype 0 showed normal-range performance on all variables. In comparison, Subtype 1 showed lower episodic memory, social cognition, functional outcome, and higher negative symptoms, while Subtype 2 showed lower hippocampal-cortical connectivity and episodic memory. Subtype 1 deteriorated from episodic memory to social cognition, negative symptoms, functional outcome to bilateral hippocampal-cortical dysconnectivity, while Subtype 2 deteriorated from bilateral hippocampal-cortical dysconnectivity to episodic memory and social cognition, functional outcome to negative symptoms. This first application of SuStaIn in a multiscale psychiatric model provides distinct disease trajectories of hippocampal-cortical connectivity, which might underlie the heterogeneous behavioral manifestations of psychosis.

Trajectories of suicidality during a 2-year early-intervention program for first-episode psychosis: A longitudinal study

Little is known about the individual course of suicidal ideations and attempts (i.e., suicidality) after treatment initiation. We examined the trajectories of suicidality and associated risk factors over a 2-year early intervention program for first-episode psychosis in 450 patients (age range 18-35 years at admission) consecutively admitted from 2003 to 2017. Suicidality was assessed via systematic file review, while sociodemographic and clinical variables were assessed at admission. Latent class growth modelling identified three trajectories: low (69.6 %), initially high (22.9 %), and persistently high (7.6 %) suicidality. Patients who were younger, lived alone and were diagnosed with affective psychosis were significantly more likely to follow the initially high trajectory. Patients who attempted suicide up to 3 months before admission, lived alone and presented lower levels of the PANSS excited factor were significantly more likely to follow the persistently high trajectory. Attempting suicide up to 3 months before admission distinguished persistently high and initially high suicidality trajectories. Suicide risk during early intervention program for first-episode psychosis is heterogenous, with acute and enduring suicidal risk, suggesting the need to adapt suicide prevention strategies to these different risk profiles.

An intersectional perspective on the sociodemographic and clinical factors influencing the status of not in Education, Employment, or training (NEET) in patients with first-episode psychosis (FEP)

PURPOSE

High rates of Not in Education, Employment or Training (NEET) are seen in people with first episode of psychosis (FEP). Sociodemographic and clinical factors were reported to be associated with NEET status in FEP patients. This study follows Intersectionality to examine the independent and additive effects, and most importantly the intersections of sociodemographic and clinical variables concerning NEET status in FEP patients. It was hypothesized that NEET status in FEP patients would be described by the intersection between at least two predictor variables.

METHODS

Secondary analyses with chi-square tests, multiple logistic regression and Chi-squared Automatic Interaction Detection (CHAID) analyses were performed on 440 participants with FEP.

RESULTS

Chi-square tests indicated that patient socioeconomic status and negative symptom severity were significantly and independently associated with their NEET status. Multiple logistic regression suggested additive effects of age (odds ratio = 1.61), patient socioeconomic status (odds ratio = 1.55) and negative symptom severity (odds ratio = 1.75) in predicting patients' NEET status. CHAID detected an intersection between patients' negative symptom severity and socioeconomic status in shaping their NEET status.

CONCLUSION

This study explored how the NEET status of patients with FEP was explained not only by the separate effects of negative symptom severity and socioeconomic status but also by the unique intersections of their clinical and social identities. Findings indicated that functional outcomes of patients appear co-constructed by the intersections of multiple identities. Crucial clinical implications of complementing care for negative symptom severity with vocational resources to improve functional outcomes of patients are discussed.

Patient- and family-reported experiences of their treating teams in early psychosis services in Chennai, India and Montreal, Canada

BACKGROUND

Cross-cultural psychosis research has mostly focused on outcomes, rather than patient and family experiences. Therefore, our aim was to examine differences in patients' and families' experiences of their treating teams in early intervention services for psychosis in Chennai, India [low- and middle-income country] and Montreal, Canada [high-income country].

METHODS

Patients (165 in Chennai, 128 in Montreal) and their families (135 in Chennai, 110 in Montreal) completed Show me you care, a patient- and family-reported experience measure, after Months 3, 12, and 24 in treatment. The measure assesses the extent to which patients and families view treating teams as being supportive. A linear mixed model with longitudinal data from patient and family dyads was used to test the effect of site (Chennai, Montreal), stakeholder (patient, family), and time on Show me you care scores. This was followed by separate linear mixed effect models for patients and families with age and gender, as well as symptom severity and functioning as time-varying covariates.

RESULTS

As hypothesized, Chennai patients and families reported more supportive behaviours from their treating teams (β=4.04; β= 9, respectively) than did Montreal patients (Intercept =49.6) and families (Intercept=42.45). Higher symptom severity over follow-up was associated with patients reporting lower supportive behaviours from treating teams. Higher levels of positive symptoms (but lower levels of negative symptoms) over follow-up were associated with families reporting lower supportive behaviours from treating teams. There was no effect of time, age, gender and functioning.

CONCLUSIONS

The levels to which treating teams are perceived as supportive may reflect culturally shaped attitudes (e.g., warmer attitudes towards healthcare providers in India vis-à-vis Canada) and actual differences in how supportive treating teams are, which too may be culturally shaped. Being expected to be more involved in treatment, Chennai families may receive more attention and support, which may further reinforce their involvement. Across contexts, those who improve over follow-up may see their treating teams more positively.

Overlap between individual differences in cognition and symptoms of schizophrenia

BACKGROUND

Neurocognitive impairment is a core feature of schizophrenia spectrum disorders (SSDs), and the relationship between cognition and symptoms in SSDs has been widely researched. Negative symptoms are related to a wide range of cognitive impairments; however, the aspects of negative symptoms that underpin this relationship have yet to be specified.

STUDY DESIGN

We used iterative Constrained Principal Component Analysis (iCPCA) to explore the relationship between 18 cognitive measures (including processing speed, attention, working, spatial and verbal memory and executive functions) and 46 symptoms in schizophrenia at the individual item level while minimizing the risk of Type I errors. ICPCA was conducted on a sample of SSD patients in the early stages of psychiatric treatment (n = 121) to determine the components of cognition overlapping with symptoms measured by the Scale for the Assessment of Negative Symptoms (SANS) and the Scale for the Assessment of Positive Symptoms (SAPS).

RESULTS

We found that a verbal memory component was associated with items from SANS and SAPS related to impoverished and disorganized emotional communication, language, and thought. In contrast, a working memory component was associated with SANS items related to motor system impoverishment.

CONCLUSIONS

The iCPCA allowed us to explore the associations between individual items, optimized to understand the overlap between symptoms and cognition. The specific symptoms linked to verbal and working memory impairments imply distinct brain networks, which further investigation may lead to our deeper understanding of the illness and the development of treatment methods.

Combinations and Temporal Associations Among Precursor Symptoms Before a First Episode of Psychosis

BACKGROUND AND HYPOTHESIS

Symptoms that precede a first episode of psychosis (FEP) can ideally be targeted by early intervention services with the aim of preventing or delaying psychosis onset. However, these precursor symptoms emerge in combinations and sequences that do not rest fully within traditional diagnostic categories. To advance our understanding of illness trajectories preceding FEP, we aimed to investigate combinations and temporal associations among precursor symptoms.

STUDY DESIGN

Participants were from PEPP-Montréal, a catchment-based early intervention program for FEP. Through semistructured interviews, collateral from relatives, and a review of health and social records, we retrospectively measured the presence or absence of 29 precursor symptoms, including 9 subthreshold psychotic and 20 nonpsychotic symptoms. Sequences of symptoms were derived from the timing of the first precursor symptom relative to the onset of FEP.

STUDY RESULTS

The sample included 390 participants (68% men; age range: 14-35 years). Combinations of precursor symptoms most frequently featured depression, anxiety, and substance use. Of 256 possible pairs of initial and subsequent precursor symptoms, many had asymmetrical associations: eg, when the first symptom was suspiciousness, the incidence rate ratio (IRR) of subsequent anxiety was 3.40 (95% confidence interval [CI]: 1.79, 6.46), but when the first symptom was anxiety, the IRR of subsequent suspiciousness was 1.15 (95% CI: 0.77, 1.73).

CONCLUSIONS

A detailed examination of precursor symptoms reveals diverse clinical profiles that cut across diagnostic categories and evolve longitudinally prior to FEP. Their identification may contribute to risk assessments and provide insights into the mechanisms of illness progression.

The effects of intranasal oxytocin on the efficacy of psychotherapy for major depressive disorder: a pilot randomized controlled trial

BACKGROUND

Although both pharmacotherapy and psychological treatments are considered to be efficacious in the treatment of major depressive disorder (MDD), one third of patients do not respond to treatment and many experience residual symptoms post-treatment. In this double-blind placebo-controlled randomized control trial (RCT), we assessed whether intranasal oxytocin (OT) augments the therapeutic efficacy of psychotherapy for MDD and improves the therapeutic alliance.

METHODS

Twenty-three volunteers (12 female) with MDD underwent 16 sessions of interpersonal therapy. Prior to each session, volunteers self-administered 24 International Units of intranasal OT (n = 12; Syntocinon) or placebo (n = 11). Depressive symptoms were assessed with the Inventory of Depressive Symptomatology at pre- and post-treatment, and at a six month follow-up.

RESULTS

Multilevel modeling found a significant effect of OT on the negative slope of depressive symptoms over time (p < 0.05), with medium-large effect sizes at post-treatment (Cohen's d = 0.75) and follow-up (Cohen's d = 0.82). Drug intervention also predicted the intercept when examining the weekly ratings of the therapeutic alliance (p < 0.05), such that volunteers receiving OT, relative to placebo, reported improved therapeutic alliance at session 1. The agreement of goals between therapists and participants, a facet of the therapeutic alliance, mediated the relationship between drug intervention and clinical outcome.

CONCLUSION

In this pilot study, the administration of intranasal OT, relative to placebo, improved the therapeutic alliance at the beginning of therapy and therapeutic efficacy of psychotherapy in persons with MDD. Future RCTs should attempt to replicate these findings in larger samples with different therapeutic modalities (ClinicalTrials.gov: NCT02405715).

Sociodemographic and clinical correlates of hallucinations in patients entering an early intervention program for first episode psychosis

Hallucinations are a core feature of psychosis, and their severity during the acute phase of illness is associated with a range of poor outcomes. Various clinical and sociodemographic factors may predict hallucinations and other positive psychotic symptoms in first episode psychosis (FEP). Despite this, the precise factors associated with hallucinations at first presentation to an early intervention service have not been extensively researched. Through detailed interviews and chart reviews, we investigated sociodemographic and clinical predictors in 636 minimally-medicated patients who entered PEPP-Montréal, an early intervention service for FEP, between 2003 and 2018. Hallucinations were measured using the Scale for the Assessment of Positive Symptoms (SAPS), while negative symptoms were assessed using the Scale for the Assessment of Negative symptoms (SANS). Depressive symptoms were evaluated through the Calgary Depression Scale for Schizophrenia (CDSS), and anxiety symptoms via the Hamilton Rating Scale for Anxiety (HAS). A majority (n = 381, 59.9 %) of the sample presented with clinically significant hallucinations (SAPS global hallucinations score ≥ 3) at program entry. These patients had an earlier age at onset, fewer years of education, and a higher severity of delusions, depression and negative symptoms than those without clinical-level hallucinations. These results suggest that individuals with clinically significant hallucinations at admission tend to be younger and have a greater overall symptom burden. This makes it especially important to monitor hallucinations alongside delusions, depression and negative symptoms in order to identify who might benefit from targeted interventions. The implications of these findings for early intervention and person-centered care are discussed.

Similar and different? A cross-cultural comparison of the prevalence, course of and factors associated with suicidal thoughts and behaviors in first-episode psychosis in Chennai, India and Montreal, Canada

BACKGROUND

Data from high-income countries (HICs) show a high risk of suicidal thoughts and behaviors (STBs) in first-episode psychosis (FEP). It is unknown, however, whether rates and associated factors differ in low- and middle-income countries (LMICs).

AIMS

We therefore aimed to compare the 2-year course of STBs and associated factors in persons with FEP treated in two similarly structured early intervention services in Chennai, India and Montreal, Canada.

METHOD

To ensure fit to the data that included persons without STBs and with varying STBs' severity, a hurdle model was conducted by site, including known predictors of STBs. The 2-year evolution of STBs was compared by site with mixed-effects ordered logistic regression.

RESULTS

The study included 333 FEP patients (168 in Chennai, 165 in Montreal). A significant decrease in STBs was observed at both sites (OR = 0.87; 95% CI [0.84, 0.90]), with the greatest decline in the first 2 months of follow-up. Although three Chennai women died by suicide in the first 4 months (none in Montreal), Chennai patients had a lower risk of STBs over follow-up (OR = 0.44; 95% CI [0.23, 0.81]). Some factors (depression, history of suicide attempts) were consistently associated with STBs across contexts, while others (gender, history of suicidal ideation, relationship status) were associated at only one of the two sites.

CONCLUSIONS

This is the first study to compare STBs in FEP between two distinct geo-sociocultural contexts (an HIC and an LMIC). At both sites, STBs reduced after treatment initiation, suggesting that early intervention reduces STBs across contexts. At both sites, for some patients, STBs persisted or first appeared during follow-up, indicating need for suicide prevention throughout follow-up. Our study demonstrates contextual variations in rates and factors associated with STBs. This has implications for tailoring suicide prevention and makes the case for more research on STBs in FEP in diverse contexts.

Patient-reported outcome measures in early psychosis: A cross-cultural, longitudinal examination of the self-reported health and self-reported mental health measures in Chennai, India and Montreal, Canada

OBJECTIVE

Despite their acknowledged value, patient-reported outcome measures (PROMs) are infrequently used in psychosis, particularly in low-and middle-income countries. We compared ratings on two single-item PROMs, Self-Rated Health (SRH) and Self-Rated Mental Health (SRMH), of persons receiving similar early psychosis services in Chennai, India and Montreal, Canada. We hypothesized greater improvements in SRH and SRMH in the Chennai (compared to the Montreal) sample.

METHODS

Participants (Chennai N = 159/168 who participated in the larger study; Montreal N = 74/165 who participated in the larger study) completed the SRH and SRMH during at least two out of three timepoints (entry, months 12 and 24). Repeated measures proportional odds logistic regressions examined the effects of time (baseline to month 24), site, and relevant baseline (e.g., gender) and time-varying covariates (i.e., symptoms) on SRH and SRMH scores.

RESULTS

SRH (but not SRMH) scores significantly differed between the sites at baseline, with Chennai patients reporting poorer health (OR: 0.33; CI: 0.18, 0.63). While Chennai patients reported similar significant improvements in their SRH (OR: 7.03; CI: 3.13; 15.78) and SRMH (OR: 2.29, CI: 1.03, 5.11) over time, Montreal patients only reported significant improvements in their SRMH. Women in Chennai (but not Montreal) reported lower mental health than men. Higher anxiety and longer durations of untreated psychosis were associated with poorer SRH and SRMH, while negative symptoms were associated with SRH.

CONCLUSIONS

As hypothesized, Chennai patients reported greater improvements in health and mental health. The marked differences between health and mental health in Montreal, in contrast to the overlap between the two in Chennai, aligns with previous findings of clearer distinctions between mind and body in Western societies. Cross-context (e.g., anxiety) and context-specific (e.g., gender) factors influence patients' health perceptions. Our results highlight the value of integrating simple PROMs in early psychosis.

Examining the psychobiological response to acute social stress across clinical stages and symptom trajectories in the early psychosis continuum

The stress-vulnerability model has been repeatedly highlighted in relation to the risk, onset and course of psychosis, and has been independently studied in clinical high-risk (CHR) and first-episode psychosis (FEP) populations. Notable in this literature, however, is that there are few studies directly comparing markers of stress response across progressive stages of illness. Here we examined the psychobiological response to the Trier Social Stress Test in 28 CHR (mean age 19.1) and 61 FEP (age 23.0) patients, in order to understand the stage(s) or trajectories in which differences in subjective stress or physiological response occur. The overall clinical sample had greater perceived stress and blunted cortisol (FEP + CHR, n = 89, age 21.7) compared with healthy controls (n = 45, age 22.9). Additional analyses demonstrated elevated heart rate and systolic blood pressure in FEP compared with CHR, but there were no further differences in physiological parameters (cortisol, heart rate, or blood pressure) between stage- or trajectory-based groups. Together, this suggests that individual stress response markers may differentially emerge at particular stages en route to psychosis - and demonstrates how stage-based analyses can shed light on the emergence and evolution of neurobiological changes in mental illness.

Trust of patients and families in mental healthcare providers and institutions: a cross-cultural study in Chennai, India, and Montreal, Canada

PURPOSE

Cross-cultural psychosis research has typically focused on a limited number of outcomes (generally symptom-related). It is unknown if the purported superior outcomes for psychosis in some low- and middle-income countries extend to fundamental treatment processes like trust. Addressing this gap, we studied two similar first-episode psychosis programs in Montreal, Canada, and Chennai, India. We hypothesized higher trust in healthcare institutions and providers among patients and families in Chennai at baseline and over follow-up.

METHODS

Upon treatment entry and at months 3, 12 and 24, trust in healthcare providers was measured using the Wake Forest Trust scale and trust in the healthcare and mental healthcare systems using two single items. Nonparametric tests were performed to compare trust levels across sites and mixed-effects linear regression models to investigate predictors of trust in healthcare providers.

RESULTS

The study included 333 patients (Montreal = 165, Chennai = 168) and 324 family members (Montreal = 128, Chennai = 168). Across all timepoints, Chennai patients and families had higher trust in healthcare providers and the healthcare and mental healthcare systems. The effect of site on trust in healthcare providers was significant after controlling for sociodemographic characteristics known to impact trust. Patients' trust in doctors increased over follow-up.

CONCLUSION

This study uniquely focuses on trust as an outcome in psychosis, via a comparative longitudinal analysis of different trust dimensions and predictors, across two geographical settings. The consistent differences in trust levels between sites may be attributable to local cultural values and institutional structures and processes and underpin cross-cultural variations in treatment engagement and outcomes.

Speech markers to predict and prevent recurrent episodes of psychosis: A narrative overview and emerging opportunities

Preventing relapse in schizophrenia improves long-term health outcomes. Repeated episodes of psychotic symptoms shape the trajectory of this illness and can be a detriment to functional recovery. Despite early intervention programs, high relapse rates persist, calling for alternative approaches in relapse prevention. Predicting imminent relapse at an individual level is critical for effective intervention. While clinical profiles are often used to foresee relapse, they lack the specificity and sensitivity needed for timely prediction. Here, we review the use of speech through Natural Language Processing (NLP) to predict a recurrent psychotic episode. Recent advancements in NLP of speech have shown the ability to detect linguistic markers related to thought disorder and other language disruptions within 2-4 weeks preceding a relapse. This approach has shown to be able to capture individual speech patterns, showing promise in its use as a prediction tool. We outline current developments in remote monitoring for psychotic relapses, discuss the challenges and limitations and present the speech-NLP based approach as an alternative to detect relapses with sufficient accuracy, construct validity and lead time to generate clinical actions towards prevention.

Maternal smoking during pregnancy and cortical structure in children with attention-deficit/hyperactivity disorder

Maternal smoking during pregnancy (MSDP) is considered a risk factor for ADHD. While the mechanisms underlying this association are not well understood, MSDP may impact the developing brain in ways that lead to ADHD. Here, we investigated the effect of prenatal smoking exposure on cortical brain structures in children with ADHD using two methods of assessing prenatal exposure: maternal recall and epigenetic typing. Exposure groups were defined according to: (1) maternal recall (+MSDP: n = 24; -MSDP: n = 85) and (2) epigenetic markers (EM) (+EM: n = 14 -EM: n = 21). CIVET-1.1.12 and RMINC were used to acquire cortical brain measurements and perform statistical analyses, respectively. The vertex with highest significance was tested for association with Continuous Performance Test (CPT) dimensions. While no differences of brain structures were identified between +MSDP and -MSDP, +EM children (n = 10) had significantly smaller surface area in the right orbitofrontal cortex (ROFc), middle temporal cortex (RTc) and parahippocampal gyrus (RPHg) (15% FDR) compared to -EM children (n = 20). Cortical surface area in the RPHg significantly correlated with CPT commission errors T-scores. This study suggests that molecular markers may better define exposure to environmental risks, as compared to human recall.

Genetic and phenotypic similarity across major psychiatric disorders: a systematic review and quantitative assessment

There is widespread overlap across major psychiatric disorders, and this is the case at different levels of observations, from genetic variants to brain structures and function and to symptoms. However, it remains unknown to what extent these commonalities at different levels of observation map onto each other. Here, we systematically review and compare the degree of similarity between psychiatric disorders at all available levels of observation. We searched PubMed and EMBASE between January 1, 2009 and September 8, 2022. We included original studies comparing at least four of the following five diagnostic groups: Schizophrenia, Bipolar Disorder, Major Depressive Disorder, Autism Spectrum Disorder, and Attention Deficit Hyperactivity Disorder, with measures of similarities between all disorder pairs. Data extraction and synthesis were performed by two independent researchers, following the PRISMA guidelines. As main outcome measure, we assessed the Pearson correlation measuring the degree of similarity across disorders pairs between studies and biological levels of observation. We identified 2975 studies, of which 28 were eligible for analysis, featuring similarity measures based on single-nucleotide polymorphisms, gene-based analyses, gene expression, structural and functional connectivity neuroimaging measures. The majority of correlations (88.6%) across disorders between studies, within and between levels of observation, were positive. To identify a consensus ranking of similarities between disorders, we performed a principal component analysis. Its first dimension explained 51.4% (95% CI: 43.2, 65.4) of the variance in disorder similarities across studies and levels of observation. Based on levels of genetic correlation, we estimated the probability of another psychiatric diagnosis in first-degree relatives and showed that they were systematically lower than those observed in population studies. Our findings highlight that genetic and brain factors may underlie a large proportion, but not all of the diagnostic overlaps observed in the clinic.

Treatment with psychostimulants and atomoxetine in people with psychotic disorders: reassessing the risk of clinical deterioration in a real-world setting

BACKGROUND

Although attention-deficit hyperactivity disorder (ADHD) is often comorbid with schizophrenia spectrum and other psychotic disorders (SZSPD), concerns about an increased risk of psychotic events have limited its treatment with either psychostimulants or atomoxetine.

AIMS

To examine whether the risk of hospital admission for psychosis in people with SZSPD was increased during the year following the introduction of such medications compared with the year before.

METHOD

This was a retrospective cohort study using Quebec (Canada) administrative health registries, including all Quebec residents with a public prescription drug insurance plan and a diagnosis of psychotic disorder, defined by relevant ICD-9 or ICD-10 codes, who initiated either methylphenidate, amphetamines or atomoxetine, between January 2010 and December 2016, in combination with antipsychotic medication. The primary outcome was time to hospital admission for psychosis within 1 year of initiation. State sequence analysis was also used to visualise admission trajectories for psychosis in the year following initiation of these medications, compared with the previous year.

RESULTS

Out of 2219 individuals, 1589 (71.6%) initiated methylphenidate, 339 (15.3%) amphetamines and 291 (13.1%) atomoxetine during the study period. After adjustment, the risk of hospital admission for psychosis was decreased during the 12 months following the introduction of these medications when used in combination with antipsychotics (adjusted HR = 0.36, 95% CI 0.24-0.54; P < 0.0001).

CONCLUSIONS

These findings suggest that, in a real-world setting, when used concurrently with antipsychotic medication, methylphenidate, amphetamines and atomoxetine may be safer than generally believed in individuals with psychotic disorders.

Pharmacological management of neurocognitive impairment in schizophrenia: A narrative review

BACKGROUND

Cognitive impairment are among the core features of schizophrenia, experienced by up to 75% of patients. Available treatment options for schizophrenia including dopamine antagonists and traditional antipsychotic medications have not been shown to confer significant benefits on cognitive deficits. Contrary to the focus on management of positive symptoms in schizophrenia, cognitive abilities are main predictor of independent living skills, functional abilities, employment, engagement in relapse prevention, and patients' subjective sense of well-being and quality of life. This review aims to provide a summary of recent literature on pharmacological options for the treatment of cognitive deficits in schizophrenia.

METHODS

We conducted a literature search of studies from 2011 to 2021 across four electronic databases including PubMed, PsycInfo, MEDLINE, and Embase. Human studies using a pharmacological treatment for cognitive impairment in schizophrenia were included.

RESULTS

Fifty-eight eligible publications, representing 11 pharmacological classes, were included in this review. Major limitations involved small sample size, methodological limitations as well as heterogeneity of participants and outcome measures.

CONCLUSIONS

Overall evidence remains inconclusive for any pharmacological classes studied for the treatment of cognitive deficits in schizophrenia. Methodological limitations in a majority of the studies rendered their findings preliminary. We further discuss possible explanations for these findings that could guide future research.

Pre-onset subthreshold psychotic symptoms are associated with differential treatment delays before a first episode of psychosis: Initial evidence and implications

BACKGROUND

Help-seeking and treatment delays are increasingly critical areas of study in mental health services. The duration of untreated psychosis (DUP), or the time between illness onset and initiation of treatment, is a predictor of symptom remission and functioning for a first episode of psychosis (FEP). The World Health Organization recommends that specialized treatment for psychosis be initiated within the first three months of FEP onset. As a result, research has focused on factors that are associated with threshold-level DUP, while the experience of subthreshold psychotic symptoms (STPS) prior to a FEP may also complicate and present barriers to accessing care for young people. We therefore examine the possibility that STPS can impact DUP and its components.

METHOD

Using a follow-back cross-sectional design, we sought to describe duration of untreated illness, length of prodrome, DUP, help-seeking delay, referral delay, and number of help-seeking contacts among FEP patients who did and did not have STPS prior to psychosis onset.

RESULTS

We found that patients who experienced STPS had a longer median duration of untreated illness, prodrome length, DUP, and help-seeking delay compared to patients who did not have such symptoms. Referral delay did not differ substantially between the two groups. Importantly, treatment delays were extremely lengthy for many participants.

CONCLUSIONS

Pre-onset STPS are associated with help-seeking delays along the pathway to care even during a FEP. Examining early signs and symptoms may help to improve and tailor interventions aimed at reducing treatment delays and ultimately providing timely care when the need arises.

Effects of Anticholinergic Burden on Verbal Memory Performance in First-Episode Psychosis

OBJECTIVES

Antipsychotics are widely used to treat first-episode psychosis but may have an anticholinergic burden, that is, a cumulative effect of medications that block the cholinergic system. Studies suggest that a high anticholinergic burden negatively affects memory in psychosis, where cognitive deficits, particularly those in verbal memory, are a core feature of the disease. The present study sought to replicate this in a large cohort of well-characterized first-episode psychosis patients. We expected that patients in the highest anticholinergic burden group would exhibit the poorest verbal memory compared to those with low anticholinergic burden and healthy controls at baseline (3 months following admission). We further hypothesized that over time, at month 12, patients' verbal memory performance would improve but would remain inferior to controls.

METHODS

Patients (n  =  311; low anticholinergic burden [n  =  241] and high anticholinergic burden [n  =  70], defined by a Drug Burden Index cut-off of 1) and healthy controls (n  =  128) completed a clinical and neurocognitive battery including parts of the Wechsler Memory Scale at months 3 and 12.

RESULTS

Cross-sectionally, using an analysis of variance, patients in the highest anticholinergic burden group had the poorest performance in verbal memory when compared to the other groups at month 3, F(2,430)  =  52.33, P < 0.001. Longitudinally, using a Generalized Estimating Equation model, the verbal memory performance of all groups improved over time. However, patients' performance overall remained poorer than the controls.

CONCLUSION

These findings highlight the importance of considering the anticholinergic burden when prescribing medications in the early stages of the disease.

Exploring the Relationship Between Suicidality and Persistent Negative Symptoms Following a First Episode of Psychosis

BACKGROUND AND HYPOTHESIS

Suicide is a leading cause of death in first-episode psychosis (FEP), with an elevated risk during the first year following illness onset. The association between negative symptoms and suicidality remains contentious. Some studies suggest that negative symptoms may be associated with lower suicidality, while others fail to find an association between the two. No previous studies have specifically investigated suicidality in Persistent Negative Symptoms (PNS) and its associated subgroups.

STUDY DESIGN

In a large cohort of FEP patients (n = 515) from an early intervention service, we investigated suicidality in those with PNS, secondary PNS (ie, sPNS; PNS with clinical-level positive, depressive, or extrapyramidal symptoms), and non-PNS (all other patients) over 24 months. Patients were categorized into PNS groups based on symptoms from month 6 to month 12, and suicidality was evaluated using the Brief Psychiatric Rating Scale (BPRS).

STUDY RESULTS

Covarying for age and sex, we found that sPNS had higher suicidality relative to PNS and non-PNS throughout the 24-month period, but PNS and non-PNS did not differ. These differences were maintained after adjusting for depressive symptoms.

CONCLUSION

We observed that PNS did not significantly differ from non-PNS. However, we identified sPNS as a group with elevated suicidality above and beyond depression, suggesting that sPNS would benefit from targeted intervention and that PNS categorization identifies a subgroup for whom negative symptoms are not associated with lower suicidality.

Context and Expectations Matter: Social, Recreational, and Independent Functioning among Youth with Psychosis in Chennai, India and Montreal, Canada

OBJECTIVES

Most cross-cultural psychosis research has focused on a limited number of outcomes (generally symptom-related) and perspectives (often clinician-/observer-rated). It is unknown if the purported superior outcomes for psychosis in some low- and middle-income countries extend to patient-reported measures of social, recreational, and independent functioning. Addressing this gap, this study aimed to compare these outcomes in first-episode psychosis at a high-income site and a lower middle-income site.

METHODS

Patients receiving similarly designed early intervention for psychosis in Chennai, India (N = 164) and Montreal, Canada (N = 140) completed the self-reported Social Functioning Scale-Early Intervention, which measures prosocial, recreation, and independence-performance functioning. Their case managers rated expected independence-performance functioning. Both sets of assessments were done at entry and Months 6, 18, and 24. Linear mixed model analyses of differences between sites and over time were conducted, accounting for other pertinent variables, especially negative symptoms.

RESULTS

Linear mixed models showed that prosocial, recreation, and independence-performance functioning scores were significantly higher in Montreal than Chennai and did not change over time. Expected independence-performance was also higher in Montreal and increased over time. Negative symptoms and education independently predicted prosocial, recreation, and expected independence-performance functioning. When added to the model, expected independence-performance predicted actual independence-performance and site was no longer significant. At both sites, prosocial and recreation scores were consistently lower (<40%) than independence-performance (40-65%).

CONCLUSION

This is the first cross-cultural investigation of prosocial, recreation, and independent functioning in early psychosis. It demonstrates that these outcomes differ by socio-cultural context. Differing levels of expectations about patients, themselves shaped by cultural, illness, and social determinants, may contribute to cross-cultural variations in functional outcomes. At both sites, social, recreational, and independent functioning were in the low-to-moderate range and there was no improvement over time, underscoring the need for effective interventions specifically designed to impact these outcomes.

Predictors of treatment attrition of cognitive health interventions in first episode psychosis

AIM

Dropping out of psychological interventions is estimated to occur in up to a third of individuals with psychosis. Given the high degree of attrition in this population, identifying predictors of attrition is important to develop strategies to retain individuals in treatment. We observed a particularly high degree of attrition (48%) in a recent randomized controlled study assessing cognitive health interventions for first-episode psychosis participants with comorbid social anxiety. Due to the importance of developing interventions for social anxiety in first episode psychosis, the aim of the present study was to identify putative predictors of attrition through a secondary analysis of data.

METHODS

Participants (n = 96) with first episode psychosis and comorbid social anxiety were randomized to receive cognitive behavioural therapy for social anxiety or cognitive remediation. Differences between completers and non-completers (<50% intervention completed) were compared using t-tests or chi-square analyses; statistically significant variables were entered into a multivariate logistic regression model.

RESULTS

Non-completers tended to be younger, had fewer years of education and had lower levels of social anxiety compared to completers. Lower baseline social anxiety and younger age were statistically significant predictors of non-completion in the logistic regression model.

CONCLUSIONS

Age and social anxiety were predictors of attrition in cognitive health interventions in first episode psychosis populations with comorbid social anxiety. In the ongoing development of social anxiety interventions for this population, future studies should investigate specific engagement strategies, intervention formats and outcome monitoring to improve participant retention in treatment.