Are there attentional deficits in people putatively at risk for affective disorders?

Sustained and selective attention deficits as vulnerability markers to psychosis

The first descriptions of schizophrenia emphasized attention problems patients with schizophrenia have but recent results evidence that other psychotic disorders share them.

We compared the performance in sustained and selective attention between psychotic patients (P), their healthy first degree relatives (R) and healthy volunteers (C) to prove whether these alterations could be an endophenotype of vulnerability to psychosis. We also compared the performance of schizophrenic patients (SZP) and that of patients with other functional psychoses (OP) in order to prove whether these alterations are specific of any psychotic disorder.

Seventy-six P, 70 R and 39 C were included in the study. A selective attention index, comprising TMT A and B and Stroop Test, and a sustained attention index comprising the Continuous Performance Test were calculated. We conducted an univariant general linear model to compare three group performances in these indexes, with age, sex and years of education as a covariables.

We found significant differences between the indexes when we compared P, R and C. No differences in performance were found between SZP and OP. Our data showed that sustained and selective attention alterations could be a vulnerability factor to psychotic disorders in general, but they were not specific of schizophrenia.

Early recognition of bipolar disorder

Bipolar disorders are frequently not diagnosed until long after their onset, leaving patients with no or correspondingly inadequate treatment. The course of the disorder is all the more severe and the negative repercussions for those affected all the greater. Concerted research effort is therefore going into learning how to recognize bipolar disorders at an early stage. Drawing on current research results, this paper presents considerations for an integrative Early Symptom Scale with which persons at risk can be identified and timely intervention initiated. This will require prospective studies to determine the predictive power of the risk factors integrated into the scale.

Prevalence of psychopathology in bipolar high-risk offspring and siblings: a meta-analysis

This meta-analysis aimed to update existing data on the comparison of prevalence rates of psychopathology primarily among offspring with at least one parent with bipolar disorder (BD) and offspring of parents without psychiatric illness. Seventeen studies were derived from a systematic search of PsychInfo, Medline, Scopus and Embase. Inclusion criteria were use of a control offspring group, standardized diagnostic procedures and reporting of clear frequency data. Risk of psychopathology was estimated by aggregating frequency data from selected studies. Compared to control offspring, high-risk BD offspring are nine times more likely to have a bipolar-type disorder, almost two and a half times more likely to develop a non-BD affective disorder and over two times more likely to develop at least one anxiety disorder. High-risk offspring also showed a significant increased risk of other non-mood psychopathology such as attention deficit hyperactivity disorder (ADHD), any type of behavioral disorder and substance use disorder (SUDs). Risk of developing a broad range of affective and non-affective psychopathology is significantly higher in high-risk BD offspring. Identifying clinical presentations of this genetically high-risk cohort is important in establishing appropriate preventative treatment.

Modulation of the N400 component in relation to hypomanic personality traits in a word meaning ambiguity resolution task

AIM

High levels of hypomanic personality traits have been associated with an increased risk of developing bipolar disorder (BD). Changes in semantic content, impaired verbal associations, abnormal prosody, and abnormal speed of language are core features of BD, and are thought to be related to semantic processing abnormalities. In the present study, we used event-related potentials to investigate the relation between semantic processing (N400 component) and hypomanic personality traits.

METHODS

We assessed 65 healthy young adults on the Hypomanic Personality Scale (HPS). Event-related potentials were recorded during a semantic ambiguity resolution task exploring semantic ambiguity (polysemous word ending a sentence) and congruency (target word semantically related to the sentence).

RESULTS

As expected, semantic ambiguity and congruency both elicited an N400 effect across our sample. Correlation analyses showed a significant positive relationship between the Social Vitality subscore of the HPS and N400 modulation in the frontal region of interest in the incongruent unambiguous condition, and in the frontocentral region of interest in the incongruent ambiguous condition.

CONCLUSION

We found differences in semantic processing (i.e., detection of incongruence and semantic inhibition) in individuals with higher Social Vitality subscores. In the light of the literature, we discuss the notion that a semantic processing impairment could be a potential marker of vulnerability to BD, and one that needs to be explored further in this clinical population.

The role of negative mood induction on working memory capacity in individuals putatively at risk for bipolar disorder: A pilot study

OBJECTIVE

Bipolar disorder (BD) is characterized by cognitive deficits. Usually individuals at risk for BD do not exhibit such deficits but they might be evident under cognitive or emotionally stressful conditions. To our knowledge this is the first study examining working memory capacity under mood induction in individuals at risk for BD.

METHODS

Using the Hypomanic Personality Scale (HPS) 68 participants out of an initial pool of 148 students were divided into groups at high and low risk for BD. They completed twice a Dual Task Paradigm (DTP) task assessed under high and low cognitive load prior to and following a negative mood induction.

RESULTS

As expected stimuli incongruency, high cognitive load and mood induction increased response times. Contrary to our hypothesis the mood induction did not differentially affect at-risk individuals. However, they generally reacted faster to neutral stimuli compared to those at low risk.

CONCLUSIONS

While we replicated former results related to the DTP, we did not find evidence for the hypothesis that individuals putatively at risk for BD will be more affected by negative mood when doing such a cognitive task. Replication using a larger sample is needed which should also examine whether changes in positive mood might more relevant in the context of risk for mania.

Neurocognitive intra-individual variability in mood disorders: effects on attentional response time distributions

BACKGROUND

Attentional impairment is a core cognitive feature of major depressive disorder (MDD) and bipolar disorder (BD). However, little is known of the characteristics of response time (RT) distributions from attentional tasks. This is crucial to furthering our understanding of the profile and extent of cognitive intra-individual variability (IIV) in mood disorders.

METHOD

A computerized sustained attention task was administered to 138 healthy controls and 158 patients with a mood disorder: 86 euthymic BD, 33 depressed BD and 39 medication-free MDD patients. Measures of IIV, including individual standard deviation (iSD) and coefficient of variation (CoV), were derived for each participant. Ex-Gaussian (and Vincentile) analyses were used to characterize the RT distributions into three components: mu and sigma (mean and standard deviation of the Gaussian portion of the distribution) and tau (the 'slow tail' of the distribution).

RESULTS

Compared with healthy controls, iSD was increased significantly in all patient samples. Due to minimal changes in average RT, CoV was only increased significantly in BD depressed patients. Ex-Gaussian modelling indicated a significant increase in tau in euthymic BD [Cohen's d = 0.39, 95% confidence interval (CI) 0.09-0.69, p = 0.011], and both sigma (d = 0.57, 95% CI 0.07-1.05, p = 0.025) and tau (d = 1.14, 95% CI 0.60-1.64, p < 0.0001) in depressed BD. The mu parameter did not differ from controls.

CONCLUSIONS

Increased cognitive variability may be a core feature of mood disorders. This is the first demonstration of differences in attentional RT distribution parameters between MDD and BD, and BD depression and euthymia. These data highlight the utility of applying measures of IIV to characterize neurocognitive variability and the great potential for future application.

Vulnerability for mania - is it linked to problems delaying gratification?

Impulsivity is described as one of the main risk factors for mania. One facet of impulsivity, the inability to delay gratification, might be of special relevance, because a hypersensitivity to reward is hypothesized to be related to mania. The main aim of this study was to examine whether risk for mania is associated with deficits in the ability to delay gratification using both a behavioral and a self-report (UPPS) measure. An additional reason for choosing the UPPS was to see if prior results about an association between risk for mania and positive urgency could be replicated. Thirty-three individuals at risk for mania and a matched control group were selected using the Hypomanic Personality Scale and interviewed for a history of mood disorders. The main outcome measures were the Single-Key-Impulsivity-Paradigm and Monetary Choice Questionnaire. The groups did not differ in measures of gratification delay but we replicated other studies reporting significantly higher levels of positive urgency and sensation seeking in at-risk individuals. We suggest that individuals at risk might not generally be more impulsive but rather that impulsive behaviors might be triggered in response to specific mood states.

Developmental trajectory of cognitive impairment in bipolar disorder: comparison with schizophrenia

Both schizophrenia and bipolar disorder (BP) are associated with neurocognitive deficits. However, it has been suggested that schizophrenia, but not BP, is characterised by premorbid cognitive impairments and neurodevelopmental abnormalities. In this paper, studies investigating neurocognitive deficits in premorbid, high-risk and first-episode BP were reviewed and these findings were compared with outcome of studies in schizophrenia. Available evidence suggests that cognitive deficits are evident in first-episode BP and such deficits can be evident even years before the onset of the illness in some patients. Trajectory of cognitive deficits from childhood to adulthood can be very similar in schizophrenia and many patients with BP. Developmental lag in acquisition of cognitive skills is a risk factor for both disorders. However, unlike schizophrenia, not only impaired cognition but also supranormal premorbid cognitive/scholastic performance predict BP. Neurodevelopmental cognitive impairment is evident in some but not all patients with BP. A model suggesting that only BP patients who share common genetic risk factors with schizophrenia have premorbid neurodevelopmental cognitive deficits is proposed. In this model, combination of absence of neurodevelopmental abnormalities and BP-related temperamental characteristics explains the relationship between supranormal cognition and risk for BP.

Inefficiency of emotion regulation as vulnerability marker for bipolar disorder: evidence from healthy individuals with hypomanic personality

OBJECTIVE

Emotion regulation deficits are a key characteristic of bipolar disorder (BD). In the present study, we asked if deficits in emotion regulation are also a vulnerability marker for BD. To this end, we investigated a healthy group of participants at high-risk for developing BD, defined on the basis of a hypomanic personality trait. We examined the neural correlates of two emotion regulation strategies, reappraisal and distraction.

METHOD

Twenty-two individuals with higher risk for BD and twenty-four controls were investigated in a functional magnetic resonance imaging paradigm. Participants were presented with negative, positive and neutral pictures and were either required to passively view the images, to down-regulate the emotional response by reappraising the pictures' content, or to perform a distracting arithmetic task.

RESULTS

High-risk individuals showed increased emotional reactivity to negative stimuli, indicated by heightened amygdala activation during passive viewing. High-risk participants were also less successful in down-regulating amygdala activity using reappraisal of negative stimuli. During distraction from positive stimuli, high-risk individuals showed heightened task-related activity in the inferior parietal cortex, suggesting increased distractibility by task-irrelevant positive background stimuli. There were no differences in habitual emotion regulation as assessed by a self-report questionnaire.

LIMITATIONS

Generalizability of the present results is limited by the age- and education-homogenous sample and the small sample size.

CONCLUSIONS

This is the first study to report neural correlates of increased emotional reactivity and deficient emotion regulation in healthy individuals at risk for BD. These findings suggest inefficient emotion regulation through reappraisal and distraction in individuals with high hypomanic personality who are supposed to be at higher risk to develop bipolar disorder.

Sustained attention as a potential endophenotype for bipolar disorder

OBJECTIVE

Nowadays, it is accepted that to identify the biological basis of psychiatric illnesses it would be useful to deconstruct them into the most basic manifestations, such as cognitive deficits. The aim of this study was to set attention deficit as a stable vulnerability marker of bipolar disorder.

METHOD

Sustained attention was evaluated by the Continuous Performance Test (DS-CPT) in 143 euthymic bipolar patients and 105 controls. To estimate the influence of clinical profile in attention, patients completed a semi-structured interview.

RESULTS

Bipolar patients showed a deficit in attention during euthymic periods. This disturbance correlated with years of evolution, age of onset and age of first hospitalisation; and was not influenced by other clinical data.

CONCLUSION

Sustained attention may be considered as an endophenotype of the illness.

Comparative study of neurocognitive function in euthymic bipolar patients and stabilized schizophrenic patients

Few studies have compared neurocognitive performance in euthymic patients with bipolar disorder (BD), stabilized patients with schizophrenia (SC) and normal controls (NC) using a comprehensive neuropsychological battery, and those that have been conducted have yielded discrepant results. We evaluated the neurocognitive profile shown by 73 euthymic patients with BD, 89 stabilized patients with SC and 67 NC. All participants completed a cognitive battery in which the domains evaluated were executive functioning, sustained attention, and verbal and visual memory. Individuals with BD were administered the Quality of Life Scale (QLS). Patients with BD manifested dysfunction in executive functioning (moderate-to-large effect size), sustained attention (moderate effect size) and verbal/visual memory (large effect size) compared with NC. Verbal memory deficit in patients with BD was related to poor functional outcome on the QLS and Global Assessment of Functioning (GAF). Patients with BD performed significantly better than patients with SC on the Trail Making Test (TMT) part B, backward digit span, and California Verbal Learning Test (CVLT) learning trials. Other neuropsychological measures showed no significant differences between the two patient groups. These findings support the notion that euthymic BD patients suffer from an extensive neurocognitive deficit that affects all cognitive domains and is qualitatively similar to that in SC patients. Persistent verbal memory impairment in BD has clinical relevance because it is associated with poor psychosocial function.

Executive performance of depressed suicide attempters: the role of suicidal ideation

OBJECTIVE

Suicidal ideation has been related to cognitive rigidity whereas suicidal behaviour itself was associated with specific executive deficits. Yet it remains unclear if a distinct cognitive suicidal phenotype does exist. The aim of the present study was to further investigate the role of suicidal thinking for the neuropsychological performance in depressive suicide attempters.

METHOD

Depressive inpatients after a recent suicide attempt, who either had present suicidal ideation (n=14) or not (n=15) and healthy controls (n=29) were recruited. The groups were assessed by means of executive tasks designed to capture impulsive decision-making, and with verbal memory and attention tests. Self-rating measures of impulsivity and aggression were further applied.

RESULTS

Only patients with current suicidal ideation showed executive dysfunctions with impaired decision-making being the most salient. Verbal memory and attention were reasonably intact in all patients. All patients reported increased aggression.

CONCLUSION

Suicidal ideation is clearly associated with impaired cognitive performance. Our results suggest that executive deficits seen in depressive suicide attempters have a state-dependent component.

Neuropsychological performance in partly remitted unipolar depressive patients: focus on executive functioning

BACKGROUND

Only few studies have investigated executive impairment in the euthymic phase of unipolar affective disorders, yielding diverging results. The role of impulsivity/orbitofrontal associated executive functioning in remitted depression has not yet been examined.

METHODS

Partly remitted male out-patients (n = 15) with non-psychotic major depression (MDD) were compared with healthy males (n = 15) on several neuropsychological tests. Executive tasks focussed on orbitofrontal function (Go/No-Go, Iowa Gambling Task (IGT), delayed alternation task). Furthermore, the Barratt Impulsiveness Scale (BIS-11) was administered to all subjects.

RESULTS

Executive skills of the patients were largely unimpaired. Patients exhibited significant deficits on measures of verbal memory only. Residual depressive symptoms in patients were correlated with diminished response inhibition. BIS-11 scores were not elevated in the patients.

CONCLUSIONS

Both executive impairment related to orbitofrontal function and self-reported impulsive behaviour in major depression seem to be state-dependent. In accordance with other studies, patients with remitted unipolar depression showed a persistent verbal memory loss.

Cognitive functions in euthymic patients with bipolar disorder

BACKGROUND

Recent studies have focused on the nature of cognitive dysfunction in bipolar patients. The purpose of the current study was to investigate cognitive performance of individuals with bipolar disorder compared to healthy control subjects during a well-established euthymic period.

METHODS

The sample consisted of 27 bipolar euthymic patients and 21 control subjects. Verbal and visual memory performance, attention, executive functions and psychosocial functions were evaluated for each participant.

RESULTS

Bipolar patients showed significant attentional deficit and executive dysfunction and also poor performance on verbal and visual memory tasks compared to the controls. Illness duration and lifetime total episode number and previous episode with psychotic features was associated with worsened performance on attention, executive and memory tasks. Psychosocial functioning was not associated with cognitive deficit.

CONCLUSIONS

The present study showed persistent cognitive impairment on inhibitory control and selective attention as well as poor performance on verbal and visual memory tests in a group of bipolar euthymic patients. The impaired neuropsychological performance was associated with duration of illness, total number of episodes per lifetime, and previous episodes with psychotic features. Attentional dysfunction seemed to be a trait abnormality for the sample studied.

Anzeichen für vermehrte subsyndromale affektive Episoden bei Vulnerabilität für bipolar affektive Störungen

Zusammenfassung. Hintergrund: Die Identifikation von Personen mit erhöhtem Risiko für bipolare Störungen kann das Verständnis ätiologischer Aspekte verbessern und langfristig präventive Optionen eröffnen. Verschiedene Studien der letzten Jahre zeigen einen Zusammenhang zwischen dem hypomanen Temperament (Skala Hypomane Persönlichkeit (Hyp)) und einem erhöhten Erkrankungsrisiko für bipolar affektive Störungen. Fragestellungen: Ziel der vorliegenden Arbeit war es zu prüfen, ob sich bei Personen, die eine psychometrisch definierte erhöhte Vulnerabilität für das bipolare Spektrum haben und bei denen bislang keine psychische Störung diagnostiziert wurde, Anzeichen für affektive Symptome bzw. subsyndromale Episoden finden lassen. Methode: Anhand der Skala Hyp wurden Jugendliche und junge Erwachsene (N = 112) in eine Gruppe mit hohen Werten in Bezug auf die Hyp-Skala (Hyp-Gruppe) und niedrige Werte (Kontrollgruppe) aufgeteilt. Sie wurden 2 Jahre später mit dem SKID für DSM-IV interviewt und füllten vier Wochen lang prospektiv ein Stimmungstagebuch aus. Ergebnisse: Auch wenn man Personen mit diagnostizierbaren psychischen Störungen einschließlich Achse-II-Störungen ausschließt, zeigen Personen der Hyp-Gruppe vermehrt Anzeichen subsyndromaler bipolarer Episoden. Auch prospektiv berichten sie von mehr affektiv depressiven und maniformen Symptomen und eine erhöhte affektive Instabilität. Schlussfolgerungen: Mit der Skala Hypomane Persönlichkeit werden Personen identifiziert, die sowohl retrospektiv als auch prospektiv vermehrt depressive und maniforme Symptome berichten, auch wenn sie nicht die Kriterien für eine psychische Störung erfüllen. Dies macht die Skala geeignet zur Untersuchung subsyndromaler bipolarer Zustände und deren Korrelate und Prozesse.

Assessing the dysregulation of the Behavioral Activation System: the Hypomanic Personality Scale and the BIS-BAS scales

We discuss the Hypomanic Personality Scale (Hyp; Eckblad & Chapman, 1986) and the Behavioral Inhibition System (BIS-BAS; Carver & White, 1994) and Behavioral Activation System (BAS; Gray, 1991) Scales as risk factors for bipolar disorders. The dysregulation of the BAS is considered to be central and results in higher variability in mood. Therefore, we examined how those scales are associated with mood fluctuations. A total of 59 participants completed a diary for at least 17 days. It included a modified Center for Epidemiologic Studies-Depression Scale (Meyer & Hautzinger, 2001) assessing depression and mania and the Positive and Negative Affect Schedule (Watson, Clark, & Tellegen, 1988). Hyp and BAS predicted levels of mania and of positive affect but also fluctuations of mania. Hyp also predicted instability of negative affect. Our data also suggest that mood variability is a trait-like feature. Both scales seem not to be perfect measures of the dysregulation factor. Future research should assess this dysregulation more directly.