Abstract
BACKGROUND: Previous studies on Internet-based treatment with minimal therapist guidance have shown promising results for several specific diagnoses. OBJECTIVE: To (1) investigate the effects of a tailored, therapist-guided, Internet-based treatment for individuals with reoccurring panic attacks, and (2) to examine whether people in different age groups (18-30 years and 31-45 years) would respond differently to the treatment. METHODS: We recruited 149 participants from an online list of individuals having expressed an interest in Internet treatment. Screening consisted of online questionnaires followed by a telephone interview. A total of 57 participants were included after a semistructured diagnostic interview, and they were randomly assigned to an 8-week treatment program (n = 29) or to a control condition (n = 28). Treatment consisted of individually prescribed cognitive behavior therapy text modules in conjunction with online therapist guidance. The control group consisted of people on a waitlist who later received treatment. RESULTS: All dependent measures improved significantly immediately following treatment and at the 12-month follow-up. The between-group effect size on the primary outcome measure, the Panic Disorder Severity Scale, was d = 1.41 (95% confidence interval 0.81-1.95) at posttreatment. The within-group effect size from pretreatment to 12-month follow-up was d = 1.66 (95% confidence interval 1.14-2.35). Age group had no effect, suggesting that age did not influence the outcome. CONCLUSIONS: Tailoring an Internet-based treatment can be a feasible approach in the treatment of panic symptoms and comorbid anxiety and depressive symptoms. Younger adults benefit as much as adults over 30 years and up to 45 years of age. TRIAL REGISTRATION: Clinicaltrials.gov NCT01296321; http://www.clinicaltrials.gov/ct2/show/NCT01296321 (Archived by WebCite at http://www.webcitation.org/65wddsqlL).