Parental history of suicide is a risk factor for suicide in offspring, but primarily in offspring without psychiatric hospitalisation.

No abstract

Previous studies support a relationship between schizophrenia and antisocial behavior. In the present study, offspring of schizophrenics showed a greater degree of antisocial behavior than did offspring of parents without psychopathology. The present study clarifies the interplay between risk for schizophrenia and developmental factors in determining antisocial behavior. Those variables which distinguished high-risk criminal behavior from high-risk non-criminal behavior were irritability and shortened attention span in infancy, paternal absence during ages 15 to 17, lower WAIS Verbal IQ, impoverished neighborhood, family discord and negative attitude towards father. In a multiple regression analysis, paternal absence in adolescence, shortness of attention span, and low Verbal IQ each contributed a unique portion of the variance in antisocial behavior. A block of interaction terms (Stressor X Risk) did not contribute a significant portion of the variance in antisocial behavior, suggesting that those factors which predict antisocial behavior in the high-risk group are the same factors which predict antisocial behavior in the low-risk group. In addition, a significant portion of the variance in phenotypic outcome (criminal vs. schizophrenic) was accounted for by passivity in infancy (predictive of schizophrenia) and low Verbal IQ (more common in high-risk criminals). Shortened attention spans in infancy were found to precede both criminal behavior and schizophrenia in this sample. This feature may therefore indicate a genetic vulnerability to schizophrenia.

Higher social class origin was associated with suicide in subjects at genetic risk for schizophrenia (but not those without risk).