Editor—The figures put forward in Gunnell and Ashby's paper on suicide rates and selective serotonin reuptake inhibitor (SSRI) antidepressants, indicative of a rising prescription rate since the launch of these drugs, may be misleading, in that a rising prescription rate does not mean a rising rate of new users.1 A formal model that translates prescriptions into patients, that we hope to submit for peer review later this year, indicates that the bulk of rising prescription rates stems not from an increasing number of new users but rather from an accumulating number of long term users of SSRIs.
Figure 1.
Credit: BERTRAND DEMEE/PHOTONICA
This point is important in that the suicide risk with SSRIs has been linked primarily to the early weeks of treatment. If this is the case, then any increase in suicides from increasing use of SSRIs in Britain will have occurred in the years from 1989 through to 1996, after which our model shows that the number of new patients starting on SSRIs stabilises, and the contribution of SSRIs to national suicide rates should remain at some constant level, provided the effects of withdrawal on inducing suicide are not too great. This latter issue has not been studied in randomised trials, although the relative risk of a suicidal act in the post-treatment phase of the recently posted paroxetine studies in children seems to be of the order of 4.3 times greater on drug than placebo.
Competing interests: In recent years DH has had consultancies with, been a principal investigator or clinical trialist for, been a chairman or speaker at international symposia for or been in receipt of support to attend meetings from various pharmaceutical companies (see bmj.com). He has been an expert witness for the plaintiff in seven legal actions involving SSRIs and has been consulted on a number of other attempted suicide, suicide cases, and suicide-homicide cases following antidepressant medication, in most of which he has offered the view that the treatment was not involved. He has also been an expert witness for the NHS in a series of LSD (46) and ECT (1) cases.
References
- 1.Gunnell D, Ashby D. Antidepressants and suicide: what is the balance between benefit and harm? BMJ 2004;329: 34-8. (3 July.) [DOI] [PMC free article] [PubMed] [Google Scholar]