Role of onset polarity in the risk of parental severe mental disorders among offspring with bipolar disorder.

BACKGROUND

Few studies have examined the association between parental severe mental disorders (SMDs) and onset polarity of bipolar disorder (BD) among their offspring. We aimed to investigate the association between parental SMDs and onset polarity of BD among their offspring.

METHODS

Offspring with BD were identified as the index group, and a demographic-matched group was selected as the controls. The primary outcome was the risk of parental SMDs, including schizophrenia, BD, depressive disorder, obsessive-compulsive disorder (OCD), alcohol use disorder (AUD), and substance use disorder (SUD). Poisson regression models with adjustments for confounders were used to estimate odds ratios (ORs) with 95 % of confidence intervals (CIs).

RESULTS

We included 20,362 individuals in the index group and 203,620 in the control group (Female: Male = 49.3 %: 50.7 %). After adjusting for confounding factors, the parents of offspring with BD had a higher risk of SMDs than the controls. This significant risk was found in the parents of offspring with mania-onset (ORs: 2.55 to 8.48), depression-onset (ORs: 3.08 to 7.83), and unspecified-onset (ORs: 2.27 to 8.16) BD. The risks of parental schizophrenia and BD were higher in the mania-onset group, while the risks of depressive disorder, OCD, AUD and SUD were higher in the depression-onset group.

LIMITATIONS: As an administrative claims database, it does not allow for definitive causal inferences between parental SMDs and offsprings' BD.

CONCLUSIONS

This study highlights the importance of the early identification of at-risk groups and specific interventions. These findings may provide useful information for clinicians in clinical practice.