Interpersonal problems as predictors of anxiety symptom trajectories in PTSD: A retrospective multilevel modeling...

This retrospective quality-control study examined whether patients with posttraumatic stress disorder (PTSD) at a specialized Norwegian inpatient hospital exhibited high levels of interpersonal problems before treatment and whether these problems predicted anxiety symptom trajectories during treatment.

The study analyzed routinely collected data from 58 inpatients with chronic PTSD (M = 44.2 years, SD = 11.0; 51.7% female) who received either Prolonged Exposure (PE) or Metacognitive Therapy (MCT) between 2016 and 2021. Multilevel modeling (MLM) was used to assess weekly self-reported anxiety symptoms measured with the Beck Anxiety Inventory (BAI). Interpersonal problems were measured at pre-treatment using the Inventory of Interpersonal Problems-64-Circumplex (IIP-64-C).

Patients exhibited significantly higher levels of interpersonal problems compared to a Norwegian non-clinical sample but did not differ significantly from a comparable clinical sample. Inconsistent with our hypothesis, higher pre-treatment interpersonal problems did not predict less improvement in anxiety symptoms during inpatient treatment. Furthermore, none of the eight IIP-64-C subscales were significantly associated with anxiety symptom change over time.

These findings suggest that while PTSD inpatients experience elevated interpersonal difficulties, these challenges may not directly hinder anxiety symptom improvement in treatment. The non-significant findings should be interpreted with caution, given the potentially underpowered sample (N = 58), which may have limited the study's ability to detect existing effects. Future research should explore time-varying covariates to better understand fluctuations in interpersonal problems and their impact on PTSD recovery.