Depression and substance use disorders in the offspring of depressed parents as a function of the parent's borderline personality disorder symptomatology.

Background: Parental major depressive disorder (MDD) and borderline personality disorder (BPD) are associated with increased risk of offspring psychopathology. It is unclear whether BPD in depressed parents infers greater risk than depression alone. We hypothesized that BPD features in depressed parents would be associated with higher morbid risk of offspring MDD and substance use disorders (SUDs).

Methods: Participants included 912 psychiatric outpatients with a principal diagnosis of MDD. Semi-structured interviews determined diagnoses of parents and their 2,011 reported offspring. We compared the offspring's morbid risk of MDD and SUDs based on whether their parents had BPD, ≥1 BPD criteria, and by each criterion.

Results: Offspring of parents with ≥1 BPD criteria had higher morbid risk of MDD and SUDs. Differences were insignificant when comparing by BPD diagnosis. Anger and impulsivity were associated with increased risk of MDD, and emptiness was associated with increased risk of SUDs.

Conclusions: Results suggest that BPD features confer additional risk to offspring beyond that of parental depression alone. Parental anger and impulsivity may be particularly important in determining risk of MDD, and parental feelings of emptiness may be particularly important for risk of SUDs. Limitations, future directions, and treatment implications are discussed.