Effectiveness of biofeedback based on respiratory parameters in the treatment of anxiety and depressive disorders

Objective. To evaluate the effectiveness of biofeedback (BF) based on respiratory parameters in the treatment of anxiety and depressive disorders. Material and methods. A systematic search was conducted using PubMed, the Cochrane Library, and eLibrary. The inclusion criteria comprised studies employing BF therapy based on respiratory parameters in patients with clinically confirmed anxiety or depressive disorders. Results. The final analysis incorporated six studies (N=1596), including three randomized clinical trials (RCTs), two observational studies, and one case series. All studies investigated the treatment of panic disorder (PD). Across all studies, a clinically significant trend was observed on the Panic Disorder Severity Scale (PDSS) within the biofeedback therapy groups. The combined intra-group effect size was Hedges’ g=1.34 (95% CI [1.27; 1.41]; z=37.9; p<0.001) with a high level of heterogeneity (I2=88%). In two RCTs that compared BF therapy with a waiting list, the intergroup effect size was also significant (Hedges’ g=1.53; 95% CI [0.23; 2.83]; z=2.3; p=0.022; I2=87%). Furthermore, two RCTs involving PD patients assessed the severity of depressive symptoms using the Beck Depression Inventory (BDI). BF therapy demonstrated a greater reduction in BDI scores versus the waiting list (Hedges’ g=1.64; 95% CI [0.87; 2.41]; z=4.1; p<0.001; I2=64%). The method was well tolerated across the studies, with no serious adverse events reported. Conclusion. The identified studies indicate that BF therapy based on respiratory parameters is highly effective in treating PD. However, the reliability of these findings remains notably low.