Positive affect training to reduce mental health problems during the COVID-19 pandemic: a proof-of-concept randomised clinical trial

Background The social restrictions occurring during the pandemic contributed to loss of many sources of reward, which contributes to poor mental health. Objective This trial evaluated a brief positive affect training programme to reduce anxiety, depression and suicidality during the pandemic. Methods In this single-blind, parallel, randomised controlled trial, adults who screened positive for COVID-19-related psychological distress across Australia were randomly allocated to either a 6-session group-based programme based on positive affect training (n=87) or enhanced usual care (EUC, n=87). Primary outcome was total score on the Hospital Anxiety and Depression Scale-anxiety and depression subscales assessed at baseline, 1-week post-treatment, 3 months (primary outcome time point) as well as secondary outcome measures of suicidality, generalised anxiety disorder, sleep impairment, positive and negative mood and COVID-19-related stress. Findings Between 20 September 2020 and 16 September 2021, 174 participants were enrolled into the trial. Relative to EUC, at 3-month follow-up the intervention led to greater reduction on depression (mean difference 1.2 (95% CI 0.4 to 1.9)), p=0.003), with a moderate effect size (0.5 (95% CI 0.2 to 0.9)). There were also greater reduction of suicidality and improvement in quality of life. There were no differences in anxiety, generalised anxiety, anhedonia, sleep impairment, positive or negative mood or COVID-19 concerns. Conclusions This intervention was able to reduce depression and suicidality during adverse experiences when rewarding events were diminished, such as pandemics. Clinical implications Strategies to improve positive affect may be useful to reduce mental health issues.