Risk and coaggregation of major psychiatric disorders among first-degree relatives of patients with bipolar disorder: a nationwide population-based study

Abstract

BackgroundBipolar disorder is a highly heritable mental illness that transmits intergeneratively. Previous studies supported that first-degree relatives (FDRs), such as parents, offspring, and siblings, of patients with bipolar disorder, had a higher risk of bipolar disorder. However, whether FDRs of bipolar patients have an increased risk of schizophrenia, major depressive disorder (MDD), autism spectrum disorder (ASD), and attention deficit hyperactivity disorder (ADHD) remains unclear.MethodsAmong the entire population in Taiwan, 87 639 patients with bipolar disorder and 188 290 FDRs of patients with bipolar disorder were identified in our study. The relative risks (RRs) of major psychiatric disorders were assessed among FDRs of patients with bipolar disorder.ResultsFDRs of patients with bipolar disorder were more likely to have a higher risk of major psychiatric disorders, including bipolar disorder (RR 6.12, 95% confidence interval (CI) 5.95–6.30), MDD (RR 2.89, 95% CI 2.82–2.96), schizophrenia (RR 2.64, 95% CI 2.55–2.73), ADHD (RR 2.21, 95% CI 2.13–2.30), and ASD (RR 2.10, 95% CI 1.92–2.29), than the total population did. These increased risks for major psychiatric disorders were consistent across different familial kinships, such as parents, offspring, siblings, and twins. A dose-dependent relationship was also found between risk of each major psychiatric disorder and numbers of bipolar patients.ConclusionsOur study was the first study to support the familial coaggregation of bipolar disorder with other major psychiatric disorders, including schizophrenia, MDD, ADHD, and ASD, in a Taiwanese (non-Caucasian) population. Given the elevated risks of major psychiatric disorders, the public health government should pay more attention to the mental health of FDRs of patients with bipolar disorder.

A nationwide population‐based longitudinal study mapping psychiatric disorders during lifetime in siblings to patients with bipolar disorder

“…Overall, findings from the study were in line with prior clinical 5,6 and epidemiological studies, [7][8][9][10] hereby confirming the validity of the register-linkage methodology of the present study. It is of interest that our findings also seem to apply outside of Scandinavian as the recent study from Taiwan 10 had similar findings.…”

“…5 The variation is likely due to heterogenous designs, methods and generally small and selected sample sizes (up to a few hundred first-degree relatives, with a few exceptions 5 ) and varying lengths of the follow-up periods. 6 Further, few epidemiological studies have targeted first-degree relatives to patients with bipolar disorder [7][8][9][10] and there is a lack of epidemiological studies that systematically have investigated rates of psychiatric disorders in high-risk individuals during lifetime. With the increasing focus on risk and resilience (the capacity to resist) in mental health, 11 it is specifically important to map the risk of developing psychiatric disorders during lifetime.…”

Preventive psychiatry: a blueprint for improving the mental health of young people

“…For example, offspring of patients affected with psychosis, bipolar disorder or depression have a greater risk of developing these disorders (32% by adulthood) 121,122 . Monozygotic twins [123][124][125][126] and first-degree relatives (depending on the number of probands) [127][128][129][130] also have an increased likelihood of developing these disorders. However, only 17.4% of the association between family history of psychosis and the disorder is mediated through a modelled polygenic risk score 131 .…”

“…First‐degree relatives (one proband: RR=6.10, two probands: RR=29.1) 128 *…”

Paths to the first‐time diagnoses of anorexia nervosa and bulimia nervosa in Taiwan

“…We therefore assume that NHI data may be more reflective of patients' naturalistic course of treatment seeking in medical settings and the degree of physicians' recognition of eating disorders. Studies using Taiwan's NHI database have expanded rapidly in both quantity and quality across many fields, including psychiatry (Chen et al, 2019; Huang et al, 2020; Wu, Liao, Tsai, Chang, & Tsai, 2017), since the first study was published in 2000 (Chen et al, 2011; Hsieh et al, 2019). Despite fundamental problems (e.g., improvement in the validity of the database), one recently published study reported that the accuracy of the diagnostic codes for major depressive disorder, schizophrenia, and dementia were acceptable, although the accuracy for bipolar disorder and minor depression were less satisfactory (Wu, Kuo, Su, Wang, & Dai, 2020).…”