Background: Depression is a major public health problem among working-age adults. The workplace is potentially an important location for interventions aimed at preventing the development of depression, but to date, the mental health impact of universal interventions in the workplace has been unclear.
Method: A systematic search was conducted in relevant databases to identify randomized controlled trials of workplace interventions aimed at universal prevention of depression. The quality of studies was assessed using the Downs and Black checklist. A meta-analysis was performed using results from studies of adequate methodological quality, with pooled effect size estimates obtained from a random effects model.
Results: Nine workplace-based randomized controlled trials (RCT) were identified. The majority of the included studies utilized cognitive behavioral therapy (CBT) techniques. The overall standardized mean difference (SMD) between the intervention and control groups was 0.16 (95% confidence interval (CI): 0.07, 0.24, P = 0.0002), indicating a small positive effect. A separate analysis using only CBT-based interventions yielded a SMD of 0.12 (95% CI: -0.01, 0.24, P = 0.07). [corrected].
Conclusions: There is good quality evidence that universally delivered workplace mental health interventions can reduce the level of depression symptoms among workers. There is more evidence for the effectiveness of CBT-based programs than other interventions. Evidence-based workplace interventions should be a key component of efforts to prevent the development of depression among adults.