Debate: No bipolar disorder in prepubertal children at high familial risk

Clinical characteristics indexing genetic differences in bipolar disorder - a systematic review

Bipolar disorder is a heterogenous condition with a varied clinical presentation. While progress has been made in identifying genetic variants associated with bipolar disorder, most common genetic variants have not yet been identified. More detailed phenotyping (beyond diagnosis) may increase the chance of finding genetic variants. Our aim therefore was to identify clinical characteristics that index genetic differences in bipolar disorder.We performed a systematic review of all genome-wide molecular genetic, family, and twin studies investigating familial/genetic influences on the clinical characteristics of bipolar disorder. We performed an electronic database search of PubMed and PsycInfo until October 2022. We reviewed title/abstracts of 2693 unique records and full texts of 391 reports, identifying 445 relevant analyses from 142 different reports. These reports described 199 analyses from family studies, 183 analyses from molecular genetic studies and 63 analyses from other types of studies. We summarized the overall evidence per phenotype considering study quality, power, and number of studies.We found moderate to strong evidence for a positive association of age at onset, subtype (bipolar I versus bipolar II), psychotic symptoms and manic symptoms with familial/genetic risk of bipolar disorder. Sex was not associated with overall genetic risk but could indicate qualitative genetic differences. Assessment of genetically relevant clinical characteristics of patients with bipolar disorder can be used to increase the phenotypic and genetic homogeneity of the sample in future genetic studies, which may yield more power, increase specificity, and improve understanding of the genetic architecture of bipolar disorder.

Long term outcomes of pediatric Bipolar-I disorder: A prospective follow-up analysis attending to full syndomatic, subsyndromal and functional types of remission

OBJECTIVE

To examine patterns of remission of pediatric bipolar I (BP-I) disorder attending to syndromatic, symptomatic, and functional outcomes from childhood to adolescent and young adult years.

METHODS

We analyzed data from a six-year prospective follow-up study of youths aged 6-17 years with BP-I disorder. Subjects were comprehensively assessed at baseline and subsequently at four, five, and six years thereafter. Assessments included structured diagnostic interviews and measures of psychosocial and educational functioning. Patterns of remission were calculated attending to whether syndromatic, symptomatic, and functional remission were achieved.

RESULTS

Kaplan-Meier failure functions revealed that the probability of functional recovery from pediatric BP-I disorder was very low. Of the 88 youths assessed, only 6% (N = 5) of the sample were euthymic with normal functioning during the year prior to their last follow-up assessment (average follow-up time = 5.8 ± 1.8 years).

CONCLUSIONS

These results provide compelling evidence of the high level of persistence of pediatric BP-I disorder. Symptomatic and functional remission were uncommon and most subjects continued to demonstrate high morbidity into late adolescence and early adulthood.

'Pediatric Bipolar Disorder' rates are still lower than claimed: a re-examination of eight epidemiological surveys used by an updated meta-analysis

Background

‘Pediatric bipolar disorder’ (PBD) is a controversial diagnosis with varying rates of clinical diagnosis. A highly cited meta-analysis (Van Meter et al. 2011) of a dozen epidemiological surveys suggested a global community prevalence of PBD of 1.8%. This was updated to 3.9% with eight additional surveys (Van Meter et al. 2019a). In terms of the Cochrane Handbook for Systematic Reviews of Interventions, the heterogenous community surveys were arguably unsuitable for statistical meta-analysis and warranted a narrative analysis. A narrative analysis (Parry et al. 2018) of the original 12 surveys concluded rates of PBD were substantially lower than 1.8% and led to a nine-article debate on the validity, arguable overdiagnosis and iatrogenic aspects of the PBD diagnosis (e.g. Carlson and Dubicka Child Adolesc Mental Health 21:86–87, 2019). This article extends the narrative analysis to include the eight newer community surveys.

Methods

A narrative analysis of the methodologies and the prevalence rates reported by the epidemiological surveys.

Results

Across all twenty surveys there was significant variation in methodologies and reported prevalence rates. Of the eight newer surveys, five (two Brazilian, one English, one Turkish, one United States) provided information of pre-adolescent prevalence rates of bipolar spectrum disorder. These pre-adolescent rates were zero or close to zero. Rates of adolescent hypomania and mania were higher, but follow-up data in two studies suggested hypomania might sometimes achieve prolonged remission or not lead to adult bipolar disorder.

Limitations

Methods in the original surveys vary and criteria used for various bipolar diagnoses were not always fully described. This limitation applies to a narrative analysis but also to a statistical meta-analysis.

Conclusion

Bipolar disorder is very rare in childhood and rare in adolescence. PBD as a diagnostic construct fails to correlate with adult bipolar disorder and the term should be abandoned. Hypomanic syndromes in adolescence may not always progress to adult bipolar disorder. Early diagnosis of bipolar disorder is important, but over-diagnosis risks adverse iatrogenic consequences.