Poorer family functioning during childhood is associated with severe mental disorders in adulthood in the general population. However, family functioning is understudied in families with parental schizophrenia or bipolar disorder. We aimed to investigate family functioning in families with 11-year-old children of parents with schizophrenia or bipolar disorder compared with controls. Second, we aimed to examine associations between family functioning and levels of child psychopathology, child global functioning, and parental social functioning.

In this prospective, population-based cohort study, we included 160 families with parental schizophrenia, 95 families with parental bipolar disorder, and 177 control families. Family functioning was measured with the 12-item version of the McMaster Family Assessment Device – General Functional Scale.

Families with parental schizophrenia (Cohen’s d = 0.29; p = .002) and parental bipolar disorder (Cohen’s d = 0.34; p = .004) had significantly poorer family functioning and a significantly higher prevalence of clinically significant family dysfunction (Cohen’s d range = 0.29–0.34; p values = .007) than control families. Across study groups, poorer family functioning was associated with higher levels of child psychopathology and poorer social functioning of the primary caregiver (p values < .001).

Children in families with parental schizophrenia or bipolar disorder are at increased risk of experiencing family dysfunction, and poorer family functioning confers risk for more symptoms of child psychopathology and poorer parental social functioning. Future studies should investigate the potentially predictive value of family dysfunction in relation to later illness onset and other adverse outcomes in these populations.