Familial coaggregation of major psychiatric disorders and neurodevelopmental disorders among first-degree relatives of individuals with generalized anxiety disorder.

BACKGROUND

Anxiety disorders, major psychiatric disorders (e.g., schizophrenia and major affective disorders), and neurodevelopmental disorders (e.g., autism and attention-deficit/hyperactivity disorder [ADHD]) may cluster together within families. However, whether the first-degree relatives (FDRs) of individuals with generalized anxiety disorder (GAD) are at an elevated risk of neurodevelopmental or major psychiatric disorders remains unknown.

METHODS

We identified 2,378,190 FDRs of patients with GAD and 9,512,760 birth year-matched and sex-matched controls from Taiwan's National Health Insurance Research Database. Neurodevelopmental disorders, including autism and ADHD, and major psychiatric disorders, including schizophrenia, bipolar disorder, major depressive disorder, obsessive-compulsive disorder, and GAD, were identified.

RESULTS

The FDRs-parents, offspring, and siblings-of individuals with GAD were more likely to be diagnosed as having schizophrenia (relative risk: 1.22), bipolar disorder (1.36), major depressive disorder (1.29), autism (1.20), ADHD (1.52), obsessive-compulsive disorder (1.21), and GAD (1.61) than are the FDRs of individuals without GAD.

CONCLUSION

Our findings support the notion of a familial coaggregation between GAD, major psychiatric disorders, and neurodevelopmental disorders. Future studies should elucidate the definitive genetic etiology of this familial coaggregation.