Family and genetic approaches have been helpful in evaluating diagnostic concepts. Using the family genetic risk score (FGRS), it’s possible to validate the genetic architecture of psychotic and affective disorders. This study aims to devise the genetic relationship between affective and psychotic disorders.

This cohort study included a total of 4,129, 002 individuals with major depression, bipolar disorder, and schizophrenia. Exposures in the study included FGRSs for major depression, bipolar disorder, and schizophrenia derived from morbidity risks. The primary outcomes of the study were diagnoses of major depression, schizophrenia, schizoaffective disorder, and other nonaffective psychoses (ONAPs).

The findings suggested that mean FGRSs for the psychiatric conditions in question produced distinct patterns for the conditions with a large separation between disorders. In the included conditions, high FGRSs were associated with the early age onset and high rates of recurrence. The findings also indicated that a high mean FGRS for bipolar disorder was associated with an early age onset and higher recurrence of major depression. Additionally, high FGRS for schizophrenia was associated with psychotic and nonpsychotic forms of bipolar disorder and major depression.

The research concluded that high FGRSs scores were clearly associated with a higher risk of psychotic disorders.