"Tolstoy’s novel Anna Karenina begins, “All happy families are alike; each unhappy family is unhappy in its own way.”1(p3) Mok et al,2 in this issue of JAMA Psychiatry, provide evidence to the contrary: in fact, many unhappy families share common risk factors. These authors report on a Danish record linkage study to elucidate the relationships between parental disorders and offspring suicide attempt and violent offending.2 The study encompassed 1 743 525 individuals born in Denmark between 1967 and 1997, followed up from their 15th birthday to the occurrence of adverse outcomes (suicide attempt or violent offending) or through 2012, whichever came first. Survival analyses were used to link parental mental disorders to the outcomes of suicide attempt and violent offending in offspring. Even controlling for the occurrence of other mental disorders and socioeconomic status (SES), parental history of cannabis misuse was related to offspring violent offending, and parental history of suicide attempt and antisocial personality disorder were associated with both offspring violent offending and offspring suicide attempt. Parental disorder conveyed a greater risk for both adverse outcomes in those of lower SES, and a greater risk of violent offending in females than in males."
*But not how Larkin supposed (i.e., environmentally); we're probably looking mostly at genetics at play in this study.