The differential effects of child abuse and posttraumatic stress disorder on schizotypal personality disorder.

OBJECTIVE: Previous findings suggest a relation between trauma exposure and risk for schizotypal personality disorder (SPD). However, the reasons for this relationship are not well understood. Some research suggests that exposure to trauma, particularly early trauma and child abuse, as well as posttraumatic stress disorder (PTSD) may play a role.

METHODS: We examined subjects (n = 541) recruited from the primary care clinics of an urban public hospital as part of an National Institute of Mental Health-funded study of trauma-related risk and resilience. We evaluated childhood abuse with the Childhood Trauma Questionnaire and the Early Trauma Inventory and SPD with the Schedule for Nonadaptive and Adaptive Personality. We assessed for lifetime PTSD using the Clinician-Administered PTSD Scale.

RESULTS: We found that of the 3 forms of abuse analyzed (emotional, physical, and sexual), only emotional abuse significantly predicted SPD (P < .001, R = 0.28) when all 3 abuse types were simultaneously entered into a regression model. Lifetime PTSD symptoms also significantly predicted SPD (P < .001, R = 0.26). Posttraumatic stress disorder was specifically predictive of 4 of the 8 SPD symptoms (P ≤ .001): excessive social anxiety, a lack of close friends or confidants, unusual perceptual experiences, and eccentric behavior or appearance. Using a Sobel test, we also found a partial mediation effect of PTSD on the relation between emotional abuse and SPD (z = 3.45, P < .001).

CONCLUSIONS: These findings point to the important influence of emotional abuse on SPD and suggest that PTSD symptoms may provide a link between damaging childhood experiences and SPD symptoms in traumatized adults.