Dimensions of manic symptoms in youth: psychosocial impairment and cognitive performance in the IMAGEN sample

The IMAGEN study: a decade of imaging genetics in adolescents

Imaging genetics offers the possibility of detecting associations between genotype and brain structure as well as function, with effect sizes potentially exceeding correlations between genotype and behavior. However, study results are often limited due to small sample sizes and methodological differences, thus reducing the reliability of findings. The IMAGEN cohort with 2000 young adolescents assessed from the age of 14 onwards tries to eliminate some of these limitations by offering a longitudinal approach and sufficient sample size for analyzing gene-environment interactions on brain structure and function. Here, we give a systematic review of IMAGEN publications since the start of the consortium. We then focus on the specific phenotype 'drug use' to illustrate the potential of the IMAGEN approach. We describe findings with respect to frontocortical, limbic and striatal brain volume, functional activation elicited by reward anticipation, behavioral inhibition, and affective faces, and their respective associations with drug intake. In addition to describing its strengths, we also discuss limitations of the IMAGEN study. Because of the longitudinal design and related attrition, analyses are underpowered for (epi-) genome-wide approaches due to the limited sample size. Estimating the generalizability of results requires replications in independent samples. However, such densely phenotyped longitudinal studies are still rare and alternative internal cross-validation methods (e.g., leave-one out, split-half) are also warranted. In conclusion, the IMAGEN cohort is a unique, very well characterized longitudinal sample, which helped to elucidate neurobiological mechanisms involved in complex behavior and offers the possibility to further disentangle genotype × phenotype interactions.

Sexual Dimorphism of Heart Rate Variability in Adolescence: A Case-Control Study on Depression, Anxiety, Stress Levels, Body Composition, and Heart Rate Variability in Adolescents with Impaired Fasting Glucose

Prediabetes in the form of impaired fasting glucose, impaired glucose tolerance, or both is considered as a preliminary stage for the onset of diabetes and diabetic complications. Hormonal fluctuations in adolescence are accompanied by body composition modifications, which are associated with insulin resistance and subclinical inflammation. Bioimpedance (BIA) accurately evaluates body composition, and heart rate variability (HRV) assesses cardiac autonomic function, which are frequently afflicted by insulin resistance. We aimed at evaluating the effect of glycemic status on mental stress, anxiety, and depression status in adolescents with impaired fasting glucose, body composition, and HRV parameters. This is a case-control study to evaluate the effect of the hyperglycemia on depression, anxiety, and stress levels (DASS21 questionnaire), body composition (BIA-ACC-BIOTEKNA©), and HRV (PPG Stress Flow-BIOTEKNA©), between euglycemic adolescents (euglycemic group) and adolescents with impaired fasting glucose (prediabetic group), aged 12-20 years. No differences were found between the prediabetic (n = 13) and the euglycemic (n = 16) groups in the outcome measures, possibly due to the number of participants. Interestingly, females, irrespective of their glycemic status, exhibited altered sympathovagal function as revealed by impaired HRV. In the euglycemic group, HRV parameters were significantly correlated and in line with the DASS21 scores, but in the prediabetic group, similarities to those of adults were observed. Impaired fasting glucose had no impact on mental health, body composition, or HRV parameters in adolescents. HRV parameters were impaired in females, irrespective of their glycemic status. This finding implies that females seem to be more prone to stress disorders, even from a young age. Future studies are needed to confirm these findings.

"Formal Thought Disorder" in a General-Community Sample With Elevated Schizotypal Traits

Different dimensions of formal thought disorder (FTD) are distinguished by different patterns of cognitive dysfunction and cortical variability in patients with schizophrenia; however, inconsistent findings may relate to patient-related confounds. Investigating FTD in nonpatient samples with elevated levels of schizotypal traits avoids these confounds, but its utility to FTD research is unknown. Thus, we performed principal components analysis (PCA) of FTD ratings using the Scale for the Assessment of Thought, Language, and Communication (TLC) and the Thought and Language Index (TLI) in a general-community sample with elevated schizotypal traits. Both scales showed "clinically elevated" FTD, particularly, the TLC. PCA described a three-component TLC solution ("disorganization," "verbosity," "emptiness") and a two-component TLI solution ("negative," "idiosyncratic"), generally consistent with schizophrenia research. TLC "disorganization" and "emptiness" were correlated with psychosis-like experiences. TLI "negative" was associated with lower general cognitive function, consistent with schizophrenia research. FTD may have shared etiology along the schizophrenia spectrum.

Debate: Dimensions of mania in youth: possibly bipolar, probably risk indicators, certainly impairing

We comment on the utility of latent manic dimensions to elucidate the prevalence of youth Bipolar Disorder in epidemiological samples, irrespective of sample's cultural background or clinician's predetermined prototypical definitions of a bipolar case.

Psychiatric symptoms and related dysfunction in a general population sample

Background

Along with the key clinical features of major psychiatric disorders such as psychosis, mania, and depression, these disorders are also associated with cognitive, social, and functional deficits. A growing body of evidence suggests that these disorders exist at the extreme end of a continuum of symptoms rather than as binary entities, so it is plausible that the associated cognitive, social, and functional deficits assume a similar pattern. Consistent with this approach, we sought to determine whether adults in the general population with psychiatric symptoms also demonstrate milder forms of the cognitive, social, and functional deficits that are often associated with the psychiatric disorders.

Methods

Using data from the Study of Resilience and Environmental Adversity in Midlife Health (STREAM), which includes survey responses of 811 individuals, we compared early academic achievement and self-reported social and functional outcomes between respondents who reported psychotic symptoms, manic symptoms, depressive symptoms, or no psychiatric symptoms (controls).

Results

Adults with psychotic symptoms had significantly poorer early academic performance (p = .04) and social and functional outcomes (self-reported marital status, p = .021, income, p = .001, and health, p < .001) than controls. Adults with depressive symptoms had significantly lower early academic performance and income and poorer health than controls (p's = 0.033, 0.037, 0.013 respectively), and adults with manic symptoms also reported significantly lower rates of marriage than controls (p = .006).

Conclusions

The results are consistent with the continuum view of the etiology of psychiatric disorders in which psychiatric disorders are dimensional and experienced in varying degrees of severity across the general and clinical population. Importantly, the results highlight the potential impact of psychiatric symptomatology on functional outcomes in the population.

Impact of irritability: a 2-year observational study of outpatients with bipolar I or schizoaffective disorder

OBJECTIVES

Many people experience irritability when manic, hypomanic, or depressed, yet its impact on illness severity and quality of life in bipolar and schizoaffective disorders is poorly understood. This study aimed to examine the relationship between irritability and symptom burden, functioning, quality of life, social support, suicidality, and overall illness severity in a naturalistic cohort of people with bipolar I or schizoaffective disorder.

METHODS

We used data from 239 adult outpatients with bipolar I or schizoaffective disorder in the Bipolar Comprehensive Outcomes Study (BCOS) - a non-interventional observational study with a 2-year follow-up period. Baseline demographic and clinical characteristics of participants with and without irritability were compared. A mixed-model repeated measures analysis was conducted to examine the longitudinal effect of irritability on clinical and quality-of-life variables over follow-up using significant baseline variables.

RESULTS

At baseline, 54% of participants were irritable. Baseline irritability was associated with illness severity, mania, depression, psychotic symptoms, suicidality, poor functioning, and quality of life, but not diagnosis (schizoaffective/bipolar disorder). Participants with irritability were less likely to have a partner and perceived less adequate social support. On average, over follow-up, those with irritability reported more symptoms, functional impairment, and suicidality. Furthermore, the effects of irritability could not be fully explained by illness severity.

CONCLUSIONS

Irritability was associated with more negative symptomatic, functional, and quality-of-life outcomes and suicidality. The identification, monitoring, and targeted treatment of irritability may be worth considering, to enhance health and wellbeing outcomes for adults with bipolar and schizoaffective disorders.

Characterization and structure of hypomania in a British nonclinical adolescent sample

BACKGROUND

This study aimed to test the validity of using the Hypomania Checklist-16 [HCL-16] to measure hypomania in a British adolescent community sample. Limited research is available concerning the characterization of hypomania among community adolescent samples, particularly in the UK, despite its potential importance for early intervention policy development.

METHOD

To explore the structure and characterization of hypomania in a British adolescent nonclinical cohort, over 1400 17 year olds (Mean=17.05 years; SD=0.88) completed the HCL-16 along with measures of different psychological and psychopathological dimensions.

RESULTS

Principal components analysis revealed a 2-component solution for the HCL-16, described as active-elated and irritable/risk-taking. Hypomanic symptoms were significantly correlated with many psychopathological dimensions. There were distinct correlation patterns for the two HCL-16 subscales, with the irritability/risk-taking subscale showing significantly stronger associations with psychotic-like experiences, internalizing and externalizing problems, and reduced life satisfaction relative to the active-elated dimension. Adolescents at 'high-risk' for bipolar disorder reported more psychopathology relative to the comparison group.

LIMITATIONS

Absence of the clinical diagnosis of bipolar disorder in the sample means that the classification of the 'high-risk' group cannot be confirmed.

CONCLUSIONS

The structure of the HCL-16 in this UK adolescent sample mirrored that observed in adult and clinical cohorts. The observed links between the HCL-16 and psychopathological dimensions that have been previously associated with both hypomania and bipolar disorder lend support to the HCL-16's validity as a hypomania instrument for adolescents. Better understanding of hypomania prior to adulthood has considerable potential for informing early intervention approaches.

Distinct relationships between social aptitude and dimensions of manic-like symptoms in youth

Difficulties with interpersonal relationships have been reported in children and adolescents with manic symptoms, even if they do not fulfil criteria for a manic episode. The role of social aptitude (SA) in youths with manic symptoms has never been examined in the general population. Moreover, no study has examined whether SA is differentially associated with dimensions of manic symptoms. We hypothesised that youth with predominantly undercontrol manic symptoms (characterised by irritability) would show lower levels of SA; conversely, youth with predominantly exuberant symptoms would show better than average social skills. Our sample comprised 5325 participants from the 2004 British Child and Adolescent Mental Health Survey (B-CAMHS04), mean age 10.3 years, SD = 3.3, 48 % girls. Manic symptoms were assessed with the Development and Wellbeing Assessment by interviewing parents and young people. Children and adolescents with manic symptoms had a lower SA score, compared to the general population by parent report, but not by self-report. SA score was higher in youths with predominantly exuberant manic symptoms compared to the general population; whereas the youths with predominantly undercontrol manic symptoms had lower SA scores by parent and self-report. Our results provide further evidence for the distinction between exuberant and undercontrol manic symptoms and highlight the need to focus on SA in future research.