An analysis of age and gender influences on the relative risk for suicide and psychotropic drug self-poisoning

Psychiatric illness is a significant risk factor for both attempted and completed suicide and psychotropic medications account for 80% of all drug overdoses involving prescription medications. One challenge facing clinicians is to balance the benefit of treatment against the risk of drug overdose. The aim of the present study was to compare the age and gender distribution of patients prescribed psychotropic drugs with patients attempting and completing suicide with these drugs. Data were obtained from the Australian census and studies of general practitioner prescribing, patients who committed suicide or presented with self-poisoning within a defined geographic area. The characteristics of these populations were compared to calculate odds ratios for attempting or completing suicide with psychotropic drugs, before and after correction for rates of prescription, in different age and gender groups. The odds ratios (ORs) for self-poisoning were higher for those aged less than 45 years and yet this group was least likely to be prescribed psychotropic drugs. Men had a much higher rate of completed suicide using more lethal methods. The ORs for self-poisoning and suicide with psychotropic drugs, after correction for prescription rates, for those aged 15 to 24 years were 11.1 and 1.7, respectively. Those aged 25 to 44 years had ORs of 4.9 and 4.3, and, by contrast, those over 75 years had ORs of 0.03 and 0. Women were slightly more likely to poison themselves with psychotropic drugs (OR 1.2). However, the situation reversed after correction for prescription rates (OR 0.69). It is concluded that greater caution should be exercised in prescribing for those under 45 years of age, given their relatively higher risk of drug overdose, and that the least toxic compounds should be used. The risk (of self-poisoning) among the elderly may have been overstated, so that some patients may have been denied the benefit of adequate treatment.