Psychological interventions have been shown to substantially reduce the risk of major depressive disorder (MDD) in adults experiencing subthreshold depressive symptoms, according to findings published in The Lancet Psychiatry.
Traditional treatments such as pharmacotherapy and psychotherapy effectively manage MDD but fail to significantly reduce its global burden. In response, researchers conducted a systematic review and individual participant data meta-analysis to evaluate and quantify the effectiveness of psychological interventions in preventing MDD.
Data was assessed from 30 randomized controlled trials comprising 7201 participants, with 3697 receiving interventions and 3504 in control groups. Of these, 86.7% were conducted in high-income countries, 30% in general adult populations, and 30% in older adults. Cognitive behavioral therapy was the intervention in 53.3% of studies and 40% were conducted in a face-to-face format.
Participants were adults without MDD at baseline but presented with subthreshold depressive symptoms. The study populations had a mean (SD) age of 49.9 (19.2) years, with 51% of those with recorded ethnicities identifying as White and 68.9% identified as women.
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Given the significant burden of depression, clinicians and policy makers should consider preventive psychological interventions as a viable option for individuals with subthreshold depression.
The primary outcome was the onset of MDD within specific timeframes: post-treatment, 6 months, 12 months, and 24 months. Secondary outcomes included changes in depressive symptom severity, response rates, and functional improvements.
Researchers found that psychological interventions significantly reduced the incidence of MDD by 43% immediately after treatment (incidence rate ratio [IRR] 0.57; 95% CI 0.35-0.93), 42% at 6 months (IRR 0.58; 95% CI 0.39-0.88), and 33% at 12 months (IRR 0.67; 95% CI 0.51-0.88).
However, no significant reduction was observed at 24 months (IRR 1.16; 95% CI 0.66-2.03). Participants without prior psychotherapy experience showed significantly greater benefits from the interventions (IRR 0.39; 95% CI 0.25-0.62) compared to those with previous experience (IRR 0.92; 95% CI 0.61-1.36; P =.029).
Within 6 months and within 12 months, interventions also led to a reduction in depressive symptom severity (standardized mean difference, -0.49 [95% CI, -0.66 to -0.32] to -0.26 [95% CI, -0.41 to -0.11]). During the study period, MDD onset was seen in 17% of intervention participants compared to 22.6% in control participants. In the 6-and 12-month time frames, the intervention groups saw a 13.4% and 17.9% onset rate, respectively. In contrast, over 6-and 12-months in the control groups, MDD onset rates were 17.9% and 21.4%, respectively.
Researchers also found that the delivery method influenced outcomes. Interventions conducted via conference telephone calls demonstrated superior efficacy compared to face-to-face, internet-based, or other delivery formats, although this conclusion was based on limited data from 2 studies.
Additionally, individuals with moderate depressive symptoms (Patient Health Questionnaire-9 score ≥10) showed a stronger reduction in MDD risk.
“Given the significant burden of depression, clinicians and policy makers should consider preventive psychological interventions as a viable option for individuals with subthreshold depression,” the researchers concluded.
Study limitations include heterogeneity across studies, insufficient long-term follow-up data, and a lack of diversity in the sample, which was predominantly White and highly educated.
Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
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