Objective: Psychological treatments can relieve mental distress and improve well-being, and the dissemination of evidence-based methods can help patients gain access to the right type of aid. Meanwhile, Internet-based cognitive–behavioral therapy (ICBT) has shown promising results for many psychiatric disorders. However, research on the potential for negative effects of psychological treatments has been lacking. Method: An individual patient data meta-analysis of 29 clinical trials of ICBT (N = 2,866) was performed using the Reliable Change Index for each primary outcome measures to distinguish deterioration rates among patients in treatment and control conditions. Statistical analyses of predictors were conducted using generalized linear mixed models. Missing data was handled by multiple imputation. Results: Deterioration rates were 122 (5.8%) in treatment and 130 (17.4%) in control conditions. Relative to receiving treatment, patients in a control condition had higher odds of deteriorating, odds ratios (ORs) = 3.10, 95% confidence interval (CI) [2.21, 4.34]. Clinical severity at pretreatment was related to lower odds, OR = 0.62, 95% CI [0.50, 0.77], and OR = 0.51, 95% CI [0.51, 0.80], for treatment and control conditions. In terms of sociodemographic variables, being in a relationship, OR = 0.58, 95% CI [0.35, 0.95], having at least a university degree, OR = 0.54, 95% CI [0.33, 0.88], and being older, OR = 0.78, 95% CI, [0.62, 0.98], were also associated with lower odds of deterioration, but only for patients assigned to a treatment condition. Conclusion: Deterioration among patients receiving ICBT or being in a control condition can occur and should be monitored by researchers to reverse and prevent a negative treatment trend.
Internet-based cognitive behavior therapy, individual patient data meta-analysis, negative effects, deterioration, predictors