[Trauma-focused and personality disorder treatment for posttraumatic stress disorder and comorbid cluster C...

Posttraumatic stress disorder (PTSD) is associated with high rates of avoidant, dependent and obsessive-compulsive personality disorders (cluster C-PD). It is unknown whether concurrent treatment for PTSD and comorbid cluster C-PD leads to superior treatment effects, compared to standalone trauma-focused treatment.

To test the efficacy of adding 52-58 sessions of PD treatment (group schema therapy; GST) to 12-18 sessions of individual trauma-focused treatment (imagery rescripting; ImRs).

130 adult outpatients were randomized to receive either ImRs or ImRs+GST. The main outcome was PTSD severity one year after start of treatment (CAPS-5). Secondary outcomes were cluster C-PD, psychiatric symptoms, quality of life, functioning, treatment response, remission, and dropout.

At 12 months, there were large decreases in PTSD severity (d = 2,4), PD symptoms and all other secondary outcomes. There were no significant differences between conditions.

Large effects were observed in both treatment arms. The results suggests that trauma focused treatment is the preferred primary treatment in patients presenting with PTSD and comorbid cluster C-PD, after which more intensive psychotherapy aimed at the personality disorder may be considered in the case of residual personality disorder symptoms.