Background: Internet-based cognitive behavioural self-help psychotherapy (ICBT) can be an important alternative or supplement to ordinary face-to-face therapy.Aim: To assess effectiveness of ICBT for adults with an anxiety disorder.Methods: Sixty-four participants were randomised to 9 weeks with the FearFighter ICBT program (n = 32) or no intervention (n = 32). Outcomes included complete remission, severity of symptoms and occurrence of adverse events.Results: No difference (p = 1.00) in remission between groups following 10 weeks of intervention nor at 37 weeks follow-up was found. There was significant reduction in the severity of symptoms (p < 0.05) at end of intervention of ICBT compared to the control group, while the reduction in symptoms at 37 weeks follow-up was equal for the two groups. Two participants in the ICBT group and none in the control group reported adverse events.Conclusion: We found no difference in remission, but a reduction of symptoms in the ICBT group compared with the control group at end of intervention. At six months follow-up the two groups showed the same level in the reduction of symptoms. Trial registration: Clinicaltrials.gov: NCT02499055. Registered 01 July 2015.
Keywords: Anxiety; cognitive behavioural therapy; internet-based psychotherapy; randomised clinical trial.