Estimating the smallest worthwhile difference of antidepressants: a cross-sectional survey

Journal article

BACKGROUND: Approximately 30% of patients experience substantial improvement in depression after 2 months without treatment, and 45% with antidepressants. The smallest worthwhile difference (SWD) refers to an intervention's smallest beneficial effect over a comparison patients deem worthwhile given treatment burdens (harms, expenses and inconveniences), but is undetermined for antidepressants. OBJECTIVE: Estimating the SWD of commonly prescribed antidepressants for depression compared to no treatment. METHODS: The SWD was estimated as a patient-required difference in response rates between antidepressants and no treatment after 2 months. An online cross-sectional survey using Prolific, MQ Mental Health and Amazon Mechanical Turk crowdsourcing services in the UK and USA between October 2022 and January 2023 garnered participants (N=935) that were a mean age of 44.1 (SD=13.9) and 66% women (n=617). FINDINGS: Of 935 participants, 124 reported moderate-to-severe depressive symptoms but were not in treatment, 390 were in treatment and 495 reported absent-to-mild symptoms with or without treatment experiences. The median SWD was a 20% (IQR=10-30%) difference in response rates for people with moderate-to-severe depressive symptoms, not in treatment, and willing to consider antidepressants, and 25% (IQR=10-35%) for the full sample. CONCLUSIONS: Our observed SWDs mean that the current 15% antidepressant benefit over no treatment was sufficient for one in three people to accept antidepressants given the burdens, but two in three expected greater treatment benefits. IMPLICATIONS: While a minority may be satisfied with the best currently available antidepressants, more effective and/or less burdensome medications are needed, with more attention given to patient perspectives.

Authors: Sahker, E; Furukawa, TA; Luo, Y; Ferreira, ML; Okazaki, K

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: BMJ Publishing Group
• Journal: BMJ Mental Health
• Volume: 27
• Issue: 1
• Pages: e300919-e300919
• Publication date: 2024-01-08
• Acceptance date: 2023-11-11
• DOI: 10.1136/bmjment-2023-300919
• EISSN: 2755-9734
• ISSN: 2755-9734
• Language: English
• Keywords: Depressive symptoms; Anxiety; Cross-sectional study; Medicine; Depression (economics); Internal medicine; Psychiatry; Antidepressant