Is Therapist Support Needed? Comparing Therapist- and Self-Guided Internet-Based CBT for Somatic Symptom Distress (iSOMA) in Emerging Adults.

Persistent somatic symptoms of varying etiology are very common in emerging adults and can lead to distress and impairment. Internet-delivered interventions could help to prevent the burden and chronicity of persistent somatic symptoms. This study investigated the impact of therapist guidance on the effectiveness of a cognitive-behavioral Internet intervention for somatic symptom distress (iSOMA) in emerging adults, as a secondary analysis of a two-armed randomized controlled trial. We included 149 university students (83.2% female, 24.60 yrs) with varying degrees of somatic symptom distress who were either allocated to the 8-week intervention with regular, written therapeutic guidance (iSOMA guided) or to the control group (waitlist), which was afterwards crossed over to receive iSOMA with guidance-on-demand (iSOMA-GoD). Primary outcomes were somatic symptom distress (assessed by the PHQ-15) and psychobehavioral symptoms of the somatic symptom disorder (assessed by the SSD-12) at pre- and post-treatment. Secondary outcomes included depression, anxiety, and disability. Both treatments showed statistically significant pre-post improvements in primary (iSOMA-guided: d = 0.86-0.92, iSOMA-GoD: d = 0.55-0.63) and secondary outcomes. However, intention-to-treat analysis revealed non-significant between-group effects for all outcomes (ps ≥ .335), after controlling for confounding variables, and effect sizes were marginal (d = -0.06 to 0.12). Overall, our findings indicate that Internet-delivered cognitive behavioral therapy with regular guidance is not unequivocally superior to guidance-on-demand in alleviating somatic symptom distress and associated psychopathology in emerging adults. As a next step, non-inferiority studies are needed to test the robustness of these findings and their impact on clinical populations.