Socioeconomic background and the developmental course of schizotypal and borderline personality disorder symptoms.

Low socioeconomic status (SES) background has been identified as a risk for several mental disorders. However evidence regarding SES and the developmental course of personality disorder (PD) has not been addressed. Nor is it clear whether an SES relationship to PD symptom course may be attributable to known associated risks. Further, specificity of such relationships to a particular PD diagnostic pattern independent of comorbidity with other PD or with depression has not been investigated. Data are from a general population studied longitudinally between ages 10 and 36 in four assessment waves. Effects of SES-associated risks on the level of symptoms of schizotypal and borderline disorders are estimated and compared to effects on depressive symptoms. Low family SES had robust modest independent effects on both PDs over the entire age span despite substantial cumulative effects of trauma history, stressful recent life events, IQ, poor parenting, and comorbid symptoms. SES effects on depressive symptoms were generally absent, but a small "protective" effect of low SES appeared when comorbidity with PD symptoms was taken into account. Cumulatively, these risks account for developmental failures of substantial magnitude and consequence, marking the importance of understanding the remaining mechanisms of SES effects and programmatic implications for minimizing associated risk.