In recent years, researchers have employed person-centered analytic methods such as latent class analysis (LCA) to examine the underlying structures of many psychiatric and substance use disorders, which have uncovered distinct subtypes in both AUD and PTSD as well as comorbid AUD-PTSD (Kessler et al., 2005; Olino et al., 2012; Vaidyanathan et al., 2011). Another body of scholarship has focused on symptom clusters within AUD (Bucholz et al., 1996; Moss et al., 2007) as well as PTSD (Breslau et al., 2005; Forbes et al., 2010). Studies have revealed commonalities between the expression of symptoms of both disorders as well as their co-occurrence which include dissociative subtypes among PTSD sufferers (Blevins et al., 2014; Wolf et al., 2012), and internalizing versus externalizing symptom profiles among those with comorbid AUD-PTSD (Forbes et al., 2010; Kessler et al., 2005; Olino et al., 2012). Generally, evidence from these and other studies of the two disorders indicates specific subtypes of individuals distinguished by those largely unaffected, those with internalizing symptoms or behaviors, those with externalizing symptoms or behaviors, and a combination internalizing-externalizing group.
