Characterization and structure of hypomania in a British nonclinical adolescent sample

Perinatal risk factors and subclinical hypomania: A prospective community study

BACKGROUND

Perinatal risk factors are implicated in the development of psychopathology, but their role in bipolar disorder (BD) and hypomania is unclear. Using data from a prospective community cohort, this is the first study to investigate the association between a range of perinatal risk factors, hypomanic symptoms, and 'high-risk' for BD in the general population.

METHODS

Parent report of perinatal events were available for 26,040 eighteen-month-olds from the Twins Early Development Study. Subsequent self-report hypomania was measured at ages 16 (Hypomania Checklist-16; N = 2943) and 26 (Mood Disorders Questionnaire; N = 7748). Participants were categorised as 'high-risk' for BD using established classifications. Linear and logistic regressions were conducted within a generalised estimating equations framework to account for relatedness in the sample.

RESULTS

Prenatal alcohol exposure (β = 0.08, SE = 0.04, p = .0002) and number of alcohol units consumed (β = 0.09, SE = 0.02, p < .0001) were associated with hypomanic symptoms at age 16, and number of alcohol units (OR = 1.13, 95 % CI:1.06-1.21, p = .0003) and maternal stress (OR = 1.68, 95 % CI:1.21-2.34, p = .002) were associated with 'high-risk' for BD age 16. Prenatal tobacco exposure (β = 0.10, SE = 0.04, p < .0001) and number of cigarettes smoked (β = 0.10, SE = 0.01, p < .0001) were associated with hypomanic symptoms and 'high-risk' for BD at age 26, although these result were attenuated controlling for parental psychiatric history.

LIMITATIONS

Familial confounding could not be fully adjusted for. Rater reports include some biases.

CONCLUSIONS

These findings show perinatal risk factors to be associated with subclinical hypomania and 'high-risk' for BD. Future work should explore the mechanisms underlying these longitudinal associations, which could shed light on prevention and intervention efforts.

Is there a 'bipolar iceberg' in UK primary care psychological therapy services?

BACKGROUND

Improving Access to Psychological Therapies (IAPT) is a primary care therapy service commissioned by England's National Health Service (NHS) for people with unipolar depression and anxiety-related disorders. Its scope does not extend to 'severe mental illness', including bipolar disorders (BD), but evidence suggests there is a high BD prevalence in ostensibly unipolar major depressive disorder (uMDD) samples. This study aimed to indicate the prevalence and characteristics of people with BD in a naturalistic cohort of IAPT patients.

METHODS

371 participants were assessed before initiating therapy. Participants were categorised by indicated diagnoses: BD type-I (BD-I) or type-II (BD-II) as defined using a DSM diagnostic interview, bipolar spectrum (BSp, not meeting diagnostic criteria but exceeding BD screening thresholds), lifetime uMDD or other. Information about psychiatric history and co-morbidities was examined, along with symptoms before and after therapy.

RESULTS

368 patients provided sufficient data to enable classification. 10% of participants were grouped as having BD-I, 20% BD-II, 40% BSp, 25% uMDD and 5% other. BD and uMDD participants had similar demographic characteristics, but patients meeting criteria for BD-I/BD-II had more complex psychiatric presentations. All three 'bipolar' groups had particularly high rates of anxiety disorders. IAPT therapy receipt was comparable between groups, as was therapy response (F9704 = 1.113, p = 0.351).

CONCLUSIONS

Notwithstanding the possibility that bipolar diathesis was overestimated, findings illustrate a high prevalence of BD in groups of people notionally with uMDD or anxiety. As well as improving the detection of BD, further substantive investigation is required to establish whether individuals affected by BD should be eligible for primary care psychological intervention.

Personality and Affective Correlates of Openness to Experience from Big Five and HEXACO Personality Models: The Dual Nature of Big Five Openness

Openness to Experience is considered to be one of the broadest personality traits. Different operationalizations of Openness to Experience within and between personality models incorporate various features of this trait. Differences in Openness facets across inventories may lead to differences in relation to certain outcomes. Hence, the current study looked to explore the personality and affective correlates of Openness domains and facets from the Big Five and HEXACO model. The sample consisted of 540 participants who completed measures assessing Openness to Experience domains and facets from Big Five and HEXACO, schizotypy, Disintegration, need for cognition, subjective well-being, and mania. Results revealed that schizotypy and Disintegration had mostly non-significant correlations with Openness domains from both models. However, multiple facets of Openness had significant both positive and negative correlations with these constructs. In contrast to HEXACO, Openness from the Big Five model could be presented with two distinct subdomains. The Pure Openness subdomain is related to higher mania, while Pure Intellect is associated with lower schizotypy, higher well-being, and higher need for cognition. Our results suggest that measuring Openness at lower structural levels provides us with more nuanced patterns of relationships among constructs.

Association of Etiological Factors for Hypomanic Symptoms, Bipolar Disorder, and Other Severe Mental Illnesses

IMPORTANCE

Subsyndromal hypomanic symptoms are relatively common in the general population and are linked to the onset of bipolar disorder. Little is known about their etiology and whether this is shared with the etiology of bipolar disorder or other mental illnesses.

OBJECTIVE

To examine the genetic and environmental architecture of hypomanic symptoms in a nonclinical youth sample and compare estimates at varying severity levels and their association with diagnosed bipolar disorder.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used phenotypic and genetic data from the Child and Adolescent Twin Study in Sweden and included individuals with International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnosis of psychiatric disorders from national registries for residents of Sweden. Associations between hypomania and polygenic risk scores for bipolar disorder, major depressive disorder and schizophrenia were also investigated. Analysis began November 2018 and ended October 2021.

MAIN OUTCOMES AND MEASURES

Hypomanic symptoms were assessed using the parent-rated Mood Disorders Questionnaire when the twins were aged 18 years. Bipolar disorder diagnosis and/or lithium prescription were ascertained from national registries for residents of Sweden. Polygenic risk scores for psychiatric disorders were calculated using independent discovery genetic data.

RESULTS

A total of 8568 twin pairs aged 18 years (9381 [54.7%] female) were included in the study. The hypomania heritability estimate was 59% (95% CI, 52%-64%) for male individuals and 29% (95% CI, 16%-44%) for female individuals. Unique environmental factors accounted for 41% (95% CI, 36%-47%) of the hypomania variance in male individuals and 45% (95% CI, 40%-50%) in female individuals. Shared environmental factors were only detected for female individuals and explained 26% (95% CI, 13%-38%) of the variance. The heritability estimates were fairly consistent across different hypomania severity groups. Moderate genetic (0.40; 95% CI, 0.21-0.58) and shared environmental (0.41; 95% CI, 0.03-0.75) correlations between hypomania and diagnosed bipolar disorder were found. Hypomania was significantly associated with the polygenic risk scores for schizophrenia (β = 0.08; SE = 0.026; P = .002) and major depressive disorder (β = 0.09; SE = 0.027; P = .001) but not bipolar disorder (β = 0.017; SE = 0.03; P = 0.57) (bipolar disorder I [β = 0.014; SE = 0.029; P = .64] or bipolar disorder II [β = 0.045; SE = 0.027; P = .10]).

CONCLUSIONS AND RELEVANCE

Higher heritability for hypomania was found for male compared with female individuals. The results highlight the shared etiologies between hypomanic symptoms, bipolar disorder, major depression, and schizophrenia in youths. Future research should focus on identifying specific shared genetic and environmental factors. These findings support a possible dimensional model of bipolar disorder, with hypomania representing a continuous trait underlying the disorder.

Precursors of self-reported subclinical hypomania in adolescence: A longitudinal general population study

Symptoms of subclinical hypomania (SHM) are common in the general population of adolescents and young adults. SHM are most often transient yet might be risk markers of later bipolar disorder. The current study aimed to assess the clinical correlates of SHM at age 11 in the general population, examine the continuity of SHM from age 11-age 16 and explore the clinical precursors of age 16 SHM. As part of the Copenhagen Child Cohort 2000, 1,632 preadolescents participated in the examination of SHM and various clinical correlates at age 11, 893 were re-assessed for SHM at age 16 years. At age 11, SHM, psychotic experiences and depressive symptoms were assessed by semi-structured psychopathological interviews. Furthermore, the participants were diagnostically assessed by the Development and Well-Being Assessment and interviewed about sleep length. At age 16, SHM was assessed by self-report, using the Hypomania Checklist-32. Cannabis use occurring at age 15 or earlier was assessed at age 16. At age 11, SHM was associated with depressive disorders (Relative Risk [RR] = 2.96 [95% CI 1.26–6.96]), interview-based depressive symptoms (RR = 9.22 [5.93–14.34]), neurodevelopmental disorders (RR = 2.94 [1.66–5.20]), psychotic experiences (RR = 4.51 [2.90–7.01]) and insufficient sleep (RR = 2.10 [1.28–3.43]. In the longitudinal analyses, age 16 SHM was preceded by age 11 SHM (RR = 1.89 [1.02–3.49]), psychotic experiences (RR = 2.06, [1.28–3.33]), emotional disorders (RR = 1.77, [1.02–3.09]) and cannabis use (RR = 3.14, [1.93–5.10]), after mutual adjustment and adjustment for sex, and sociodemographic factors. In conclusion, age 11 SHM was statistically significantly associated with other types of psychopathology in cross-sectional analyses and showed some continuity with later self-reported SHM at age 16. Particularly early psychotic experiences and cannabis use stood out as independent precursors of self-reported SHM and might constitute important risk markers for the development of future SHM and bipolar disorder. An important potential caveat of the current study includes the self-report assessment of SHM.

Examining the association between childhood autistic traits and adolescent hypomania: a longitudinal twin study

BACKGROUND

There is evidence that autism spectrum disorders (ASDs) co-occur with bipolar disorder (BD) relatively frequently. Individuals with BD often report symptoms of mania and hypomania during adolescence, prior to the age of onset for BD. It is unknown whether these symptoms are associated with ASDs. We examined whether diagnoses of ASDs and autistic traits were associated with hypomania in a large, population-based Swedish twin sample.

METHODS

Parental structured interviews assessed autistic traits, and were used to assign screening diagnoses of ASDs, when twins were aged 9 or 12 (N = 13 533 pairs). Parents then completed questionnaires assessing hypomania when the twins were aged 15 and 18 (N = 3852 pairs at age 15, and 3013 pairs at age 18). After investigating the phenotypic associations between these measures, we used the classical twin design to test whether genetic and environmental influences on autistic traits influence variation in adolescent hypomania.

RESULTS

Autistic traits and ASD diagnoses in childhood were associated with elevated scores on the measures of adolescent hypomania. Twin analyses indicated that 6-9% of the variance in hypomania was explained by genetic influences that were shared with autistic traits in childhood. When repeating these analyses for specific autistic trait domains, we found a stronger association between social interaction difficulties and hypomania than for other autistic trait domains.

CONCLUSIONS

These results indicate a genetic link between autistic traits and hypomania in adolescence. This adds to the growing evidence base of genetic factors associated with ASDs showing links with psychiatric outcomes across childhood and into adulthood.

Association of Genetic and Environmental Risks for Attention-Deficit/Hyperactivity Disorder With Hypomanic Symptoms in Youths

IMPORTANCE

Attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder are highly comorbid, with significantly associated symptoms. The mechanisms that account for their co-occurrence are not known.

OBJECTIVE

To examine the degree to which genetic and environmental risk factors for ADHD traits, across childhood and adolescence, are associated with adolescent hypomanic symptoms.

DESIGN, SETTING, AND PARTICIPANTS

This study used data on 13 532 twin pairs from the Child and Adolescent Twin Study in Sweden, a prospective, longitudinal twin study. Their parents provided ADHD data when children were 9 or 12 years of age. Of those who reached 15 years of age, 3784 participated. Of those who reached 18 years of age, 3013 participated. The study was performed from December 20, 2017, to December 5, 2018. Data analysis was performed at the Department of Medical Epidemiology & Biostatistics, Karolinska Institutet, Stockholm, Sweden, from March 1, 2018, to October 31, 2018.

MAIN OUTCOMES AND MEASURES

Attention-deficit/hyperactivity disorder traits and hypomanic symptoms were assessed using parent-rated instruments. Associations between ADHD and adolescent hypomanic symptoms across childhood and adolescence were investigated using generalized estimating equations. Multivariate twin models were used to examine the extent to which genetic and environmental risk factors for ADHD were associated with hypomania.

RESULTS

Among 3784 15-year-old twin pairs and 3013 18-year-old twin pairs, ADHD and hypomanic symptoms were significantly associated (age 15 years: β = 0.30; 95% CI, 0.24-0.34; P < .001; age 18 years: β = 0.19; 95% CI, 0.16-0.22; P < .001), especially for the hyperactivity-impulsivity ADHD symptom domain (age 15 years: β = 0.53; 95% CI, 0.46-0.60; P < .001; age 18 years: β = 0.36; 95% CI, 0.30-0.42; P < .001) compared with the inattention domain (age 15 years: β = 0.40; 95% CI, 0.34-0.47; P < .001; age 18 years: β = 0.24; 95% CI, 0.19-0.29; P < .001). Between 13% and 29% of the genetic risk factors for hypomania were also associated with ADHD, with higher estimates detected for symptoms of hyperactivity-impulsivity (10%-25%) compared with inattention (6%-16%). Environmental factors played a negligible role in the associations. Genetic factors unique to adolescent hypomania were associated with 25% to 42% of its variance, suggesting some etiologic distinction between these forms of psychopathology.

CONCLUSIONS AND RELEVANCE

More than a quarter of the genetic risk factors for adolescent hypomanic traits were also associated with ADHD symptoms in childhood and adolescence, with hypomania-specific genetic risk factors detected. These findings suggest that ADHD and hypomanic symptoms are associated with shared genetic factors, which should be the focus of further research.

Validation of the Hypomanic Personality Scale (HPS) in Iranian adolescents

BACKGROUND

The main purpose of the current study was to examine the psychometric properties of the Hypomanic Personality Scale (HPS) in Iranian adolescents.

METHODS

A number of 805 high school and freshman students answered the HPS, the Hypomania scale of the MMPI-2, the Borderline Traits Questionnaire (STB) and the Schizotypal Personality Questionnaire-Brief. Data were analysed using explanatory factor analysis, Pearson correlation coefficient as well as independent t-test.

RESULTS

Principal component analysis led to the extraction of two factors namely mood volatility/excitement and social vitality. Convergent validity coefficients were equal to 0.71, 0.57 and 0.74 for the total scale, mood volatility/excitement and social vitality subscales respectively. Test-retest reliability of the total scale and its subscales were equal to 0.61, 0.67 and 0.57 respectively. Internal consistency and the split-half reliability of the total scale and the two subscales showed the same coefficients. The results showed that the female group gained higher scores on the total scale and the social vitality subscale.

DISCUSSION

The results supported the multi-dimensional structure and psychometric properties of the HPS among Iranian adolescents.

CONCLUSIONS

The findings of this study confirm the use of HPS as a valid scale in investigating hypomanic characteristics, particularly among Iranian adolescents. © 2018 John Wiley & Sons, Ltd.

Comparing the screening property of the shortened versions of the Hypomania Checklist-32 (HCL-32): Cross-validation in Korean patients with bipolar disorder and major depressive disorder

BACKGROUND

To date, shortened versions of the Hypomania Checklist-32 (HCL-32) were proposed to overcome the limitation of a lengthy format; however, a cross-validation study is currently needed to identify which shorter version may function optimally in a clinical sample.

METHODS

In a Korean patient sample with bipolar disorder (BD) and major depressive disorder (MDD) (BD-I n = 84, BD = II n = 145, MDD n = 285), we examined the reliability and screening property of three shorter versions of the HCL (HCL-20, -16, -8) in comparison with the full HCL-32. Diagnosis was confirmed by the structured clinical interview (SCID-I).

RESULTS

All three shortened HCLs demonstrated a fair screening ability (Area Under the Curve = .72~.74) to discriminate BD patients from MDD patients, which was comparable to that of the HCL-32. When sensitivity and specificity were considered, the HCL-20 showed relatively superior performance among the shortened versions.

LIMITATIONS

The shorter versions were not administered in a 'stand-alone' manner.

CONCLUSIONS

This is the first cross-validation study in a large clinical sample with an increased statistical power to compare the screening property of the shortened HCLs. Our results suggest that briefer versions of the HCL could be reliably and economically utilized in clinical and research settings to enhance detection of BD.