Antidepressants and counselling for major depression in primary careBMJ 2001; 323 doi: https://doi.org/10.1136/bmj.323.7307.282 (Published 04 August 2001) Cite this as: BMJ 2001;323:282
Authors' conclusions were not justified by findings
- Wai-Ching Leung (email@example.com), honorary lecturer in public health medicine
- University of East Anglia, Norwich NR4 7TJ
- Department of Psychiatry, University of Southampton, Southampton SO14 0YG
- East London and City Mental Health NHS Trust, Royal London Hospital, London E1 1BB
- Trent Institute for Health Services Research, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH
EDITOR—In their randomised trial of antidepressant drugs and generic counselling for treating depression, Chilvers et al concluded that generic counselling is as effective as antidepressants and that general practitioners should allow patients to have their preferred treatment.1 Their findings do not, however, support these conclusions.
The authors based their sample size calculation on a difference in mean Beck scores of 5 points as the outcome and found that 44 patients in each arm were required for a power of 80%. This sample size was not achieved in the randomised arms. They did not calculate the sample sizes required for global outcome or remission, but they are likely to be much larger as these outcome variables are categorical. Therefore, the only finding which achieved a power of 80% was related to Beck scores in the combined group of randomised patients and patients expressing preference.
Both general practitioner's rating and the score for research diagnostic criteria in table 1 show that patients choosing counselling were objectively significantly less depressed than the other groups, although their Beck inventory scores were similar. In other words, compared with the other groups, patients choosing counselling were comparatively more depressed subjectively than objectively. These patients were less depressed objectively and might respond more readily than other groups to interventions. Therefore, Chilvers et al should not have combined randomised patients with patients who expressed a preference. Furthermore, they cannot conclude that generic counselling is as effective as antidepressants simply from the apparent lack of differences in Beck scores in the combined patients who expressed a preference.
Chilvers et al further concluded that general practitioners should allow patients to have their preferred treatment. While this recommendation might be …