Shared deficits of education, marital and occupational functioning in unaffected siblings of multiple affected families with major psychiatric illness.

BACKGROUND: Major psychiatric illnesses often cluster in families, and their impact on affected and unaffected members within families may reflect the consequence of both genetic and social liability.

METHODS: Data was derived from 202 families with multiple affected individuals. Affected individuals (N = 259) had a diagnosis of schizophrenia, bipolar disorder, obsessive-compulsive disorder or substance use disorder. For comparison, we used the unaffected siblings from the same families (N = 229) and a matched random subset of healthy control (HC) data (N = 229) from India's National Mental Health Survey, 2016 (NMHS). We compared the three groups' educational attainment, functional marital status, and occupational status.

RESULTS: The highest educational attainment was significantly different between the groups. The affected and unaffected siblings had poorer educational attainment compared to HC. Similarly, the affected and unaffected siblings more often remained single, in contrast to HC. Moreover, employment rates were significantly higher in the unaffected siblings, especially female siblings. Overall, females had spent fewer years at school, were primarily married, and were majority homemakers across the three groups compared to males.

DISCUSSION: Affected and unaffected siblings had lower education and marriage rates than HC. The unaffected siblings were more likely to be employed than HC. Whether the poor educational attainment and lower marriage rates in unaffected siblings is a biological marker of shared endophenotype or the effect of the social burden of having an affected family member requires further systematic evaluation.