Intended for healthcare professionals

Rapid response to:


Selective serotonin reuptake inhibitors

BMJ 2005; 330 doi: (Published 17 February 2005) Cite this as: BMJ 2005;330:420

Rapid Response:

THREAD looks at effectiveness, not efficacy

The unique contribution of the THREAD Study is to look at the
effectiveness (rather than efficacy), of an SSRI plus supportive care
versus supportive care alone. It is a ‘real-life’ pragmatic trial which
is able to examine the effects of prescribing on the process and outcome
of care, incorporating rather than controlling for the placebo effect. We
are also able to examine cost-effectiveness, which you can't study with a
placebo-controlled trial, as placebos aren't usually prescribed in
practice and so the costs of the placebo arm are impossible to interpret
for practice.

Patients in either arm may be referred for counselling, CBT, or other
psychotherapy, if this is part of usual care from the GP, but the large
majority will not receive this within the 12 week treatment period. We
have standardised the number of visits to the doctor for supportive care
in both arms, to control for the amount of time spent with the patient.
Rather than standardising what the doctor tells the patient about
depression however, we are actually very interested in what the doctor
talks about, and are measuring this through a patient questionnaire at the
end of treatment, to see whether the patients in the non-antidepressant
arm get more discussion of their life problems and possible solutions,
because the doctor is refraining from prescribing and therefore doesn’t
spend so long talking about the drug effects and side-effects. This is a
possible benefit of not prescribing, which has not been examined before as
far as we are aware.

Competing interests:
Chief Investigator of THREAD Study

Competing interests: No competing interests

15 March 2005
Tony Kendrick
Professor of Primary Medical Care
THREAD Study Group
University of Southampton SO16 5ST