Trajectories of PTSD and substance use disorders in a longitudinal study of personality disorders.

This study investigated the co-occurrence of posttraumatic stress disorder (PTSD) and substance use disorders (SUDs) in a sample ( N = 668) recruited for personality disorders and followed longitudinally as part of the Collaborative Longitudinal Personality Disorders Study. The study both examined rates of co-occurring disorders at baseline and temporal relationships between PTSD and substance use disorders over 4 years. Subjects with a lifetime history of PTSD at baseline had significantly higher rates of SUDs (both alcohol and drug) than subjects without PTSD. Latent class growth analysis, a relatively novel approach used to analyze trajectories and identify homogeneous subgroups of participant on the basis of probabilities of PTSD and SUD over time, identified 6 classes, which were compared with respect to a set of functioning and personality variables. The most consistent differences were observed between the group that displayed low probabilities of both SUD and PTSD and the group that displayed high probabilities of both.