Objective: No study has investigated clinical or genetic predictors and moderators of Internet-based cognitive behavior therapy (ICBT) compared with cognitive behavioral group therapy for (CBGT) for SAD. Identification of predictors and moderators is essential to the clinician in deciding which treatment to recommend for whom. We aimed to identify clinical and genetic (5-HTTLPR, COMTval158met, and BDNFval66met) predictors and moderators of ICBT and CBGT.
Method: We performed three types of analyses on data from a sample comprising participants (N = 126) who had undergone ICBT or CBGT in a randomized controlled trial. Outcomes were i) end state symptom severity, ii) SAD diagnosis, and iii) clinically significant improvement.
Results: The most stable predictors of better treatment response were working full time, having children, less depressive symptoms, higher expectancy of treatment effectiveness, and adhering to treatment. None of the tested gene polymorphisms were associated with treatment outcome. Comorbid general anxiety and depression were moderators meaning that lower levels were associated with a better treatment response in ICBT but not in CBGT.
Conclusion: We conclude that demographic factors, symptom burden, adherence, and expectations may play an important role as predictors of treatment outcome. The investigated gene polymorphisms do not appear to make a difference.
Trial registration: ClinicalTrials.gov NCT00564967.
© 2012 John Wiley & Sons A/S.