A recent cross-national study of 62 developing and developed countries reported an increase in suicide rates with aging in males and females in 25 and 27 countries respectively (Shah, Reference Shah2007). Longitudinal studies over time have reported a decline in elderly suicide rates in England and Wales (Gunnell et al., Reference Gunnell, Middleston, Whitley, Doring and Frankel2003; Lodhi and Shah, Reference Lodhi and Shah2004), Sweden (Carlsten et al., Reference Carlsten, Waern and Allebeck1999) and Australia (Hall et al., Reference Hall, Mant, Mitchell, Rendle, Hickie and McManus2003) with an increase in prescription rates of antidepressants, particularly selective serotonin reuptake inhibitors. The vast majority of elderly suicide victims have depressive illness (Shah and De, Reference Shah and De1998). The pathway to elderly depressed individuals acquiring a prescription of antidepressants includes the following sequential steps: recognition by individuals or their carers that there is problem and consulting a healthcare professional; recognition of depression by the healthcare professional; prescription of antidepressants by the healthcare professional; and, purchasing of the antidepressants by the patient. Different methods of acquiring the prescribed antidepressants exist in different countries including: healthcare professionals dispensing the antidepressant free or at a cost; and obtaining the prescribed antidepressant from a pharmacist free (either through state welfare system or insurance schemes) or at a cost. We have examined the relationship between elderly suicide rates and the affordability of psychotropic medication in a cross-national study.
Two unidirectional hypotheses were tested: (1) there would be a negative correlation between elderly suicide rates and affordability of antidepressants given a strong relationship between depression and elderly suicide; and (2) there would be no association between elderly suicide rates and affordability of anti-dementia drugs given the unequivocal relationship between dementia and elderly suicides. One null hypothesis was tested: there would be no relationship between elderly suicide rates and affordability of antipsychotic drugs given a weak association between schizophrenia and elderly suicides.
The International Psychogeriatric Association's Mental Health Economic Task Force, led by Professor G.K. Suh, has recently produced data on the affordability of psychotropic drugs in 20 countries as measured by the affordability index (AI). The AI is a measure of the number of tablets of a particular psychotropic medication at a particular dose that can be purchased with one day's income. Data on the AI were available for the following drugs for different preparations and doses: anti-dementia drugs (donepezil, galanthamine, rivastigmin and memantine); antidepressants (moclobemide, citalopam, sertraline, paroxetine, mirtazepine, venlofaxine and bupropion); and antipsychotics (amisulpiride, aripiprazole, clozapine, olanzapine, risperidone, quetiapine and zis).
Data on suicide rates for males and females for the general population and specifically in the age-bands 65–74 years and 75+ years were ascertained from the WHO website (www.who.int/whosis/database/mort/table1.cfm) for the latest available year. Spearman's rank correlation test (ρ) was used to examine the relationship between suicide rates for males and females in the general population and specifically in the age-bands 65–74 years and 75+ years and the AI index for all the different doses and preparations of all the psychotropic drugs listed above.
Data on both the AI and suicide rates were available for a median (range) of 9 (2–15) countries depending on the precise psychotropic drug, dose and preparation (not all doses and all drugs were available in all the countries). There was no significant correlation between AI and suicide rates in any group with three exceptions. There was a positive correlation between the male general population suicide rate and the AI of clozapine 25 mg (ρ = 0.76, p = 0.006) and clozapine 100 mg (ρ = 0.71, p = 0.022); in females this relationship was only seen with clozapine 100 mgs (ρ = 0.63, p = 0.039). The significance of these correlations disappeared when corrections for multiple comparisons were applied.
The absence of correlation between AI and elderly suicide rates is not consistent with earlier reports of a decline in elderly suicide rates with an increase in prescription rates of antidepressants in England and Wales (Gunnell et al., Reference Gunnell, Middleston, Whitley, Doring and Frankel2003; Lodhi and Shah, Reference Lodhi and Shah2004), Sweden (Carlsten et al., Reference Carlsten, Waern and Allebeck1999) and Australia (Hall et al., Reference Hall, Mant, Mitchell, Rendle, Hickie and McManus2003). There may be several reasons for this. First, the sample size was small. Second, some countries may use older antidepressants for which data on the AI were absent. Third, the AI does not take into account awareness of depression among individuals and their carers, identification of depression by healthcare professionals, appropriateness of treatment for depression offered by healthcare professionals, and compliance for taking antidepressants by patients. Fourth, the AI does not take account of different payment systems for prescriptions: in some countries healthcare professionals may dispense medication directly without charging the patient; in countries with welfare systems elderly patients may be exempt from paying directly for their prescription; and, in other countries, prescription costs may be covered by insurance. Fifth, treatments such as cognitive behavior therapy may be offered in some countries instead of antidepressants.
If the AI for all antidepressants can be calculated for all the countries where the patient has to pay for the antidepressant prescription at the time of presenting the prescription then the true relationship between elderly suicide rates and the AI of antidepressants can be examined.
