Placebo treatment was meaninglessBMJ 1995; 310 doi: https://doi.org/10.1136/bmj.310.6989.1267a (Published 13 May 1995) Cite this as: BMJ 1995;310:1267
- Liam Smeeth
EDITOR,—Describing the design of their study, L M Mynors-Wallis and colleagues state that they compared “(a) problem solving; (b) amitriptyline with standard clinical management; and (c) drug placebo with standard clinical management.”1 The patients in the second two groups, however, were seen by therapists who were under strict instructions with regard to the type of interventions they could make. The therapists were instructed to avoid specific psychological interventions, in particular problem solving treatment. If patients raised a problem it was to be listened to sympathetically, but no advice could be given on how to manage the problem. It is difficult to believe that this would constitute any therapist's or doctor's standard clinical management. The fact that problem solving treatment compared favourably with such abnormally restricted treatments is of little clinical use.
To compound this error, the three therapists were all authors of the paper. They carried out both the problem solving treatment and the standard clinical management. In this situation, bias against the groups given standard management would have been difficult to avoid and impossible to compensate for.
I also wish to raise the ethical issue of randomisation. Most patients with major depression show a good response to antidepressants,2 and cognitive therapy has also been shown to be effective.3 In Mynors-Wallis and colleagues' study one group of patients was allocated to a placebo drug and a highly restricted psychological treatment of unknown benefit. Altogether 60% of patients in this group had dropped out at three months, most (eight of 14) because they were not getting better. These patients were effectively denied access to treatment of known benefit. As Gore and Altman have pointed out, too many studies compare a new treatment with a placebo rather than an existing proved treatment.4 This process is both ethically suspect and likely to yield results of no practical importance.
Problem solving treatment could potentially be a useful addition to the treatments available for depression. I suggest, however, that a trial should be carried out to compare problem solving treatment with “treatment as usual by the general practitioner” (in most cases consisting of antidepressants or supportive counselling, or both). This would avoid the ethical problems associated with placebo treatment and would yield a far more useful result.