Suicidal behaviour is among the leading causes of death and disease burden around the world.1
The World Health Organization (WHO) estimates that in 2002 alone, approximately 877,000 deaths worldwide were due to suicide2
, making it an important worldwide public health concern in both the developed and developing world. Although there is an abundance of epidemiological research on the prevalence of suicide from the developed world3,4
, limited data exists from less developed countries. However, recently data from a nationally representative sample in South Africa revealed comparable estimated lifetime prevalence of suicide ideation (9.1 %), plans (3.8%), and attempts (2.9%) to more developed countries.5
Although the etiology of suicide is not well-understood, numerous studies in developed countries have found that mental disorders, particularly depressive disorders, are one of the strongest risk factors for suicide attempts and suicide deaths.6
This risk has also shown to decline after treatment and recovery.7
Nevertheless, as most studies have considered only one disorder, it is not exactly clear which mental disorders predict suicidal behaviours. For example, findings on the role of panic disorder in predicting suicide attempts are altered when controlling for a range of comorbid disorders.8,9
To obtain a better understanding of the direct relationship between mental disorders and suicidal behaviour, studies accounting for the effects of co-occuring mental disorders are essential.
The relationship between prior mental disorders and subsequent suicide has been primarily studied in the developed world4,10
, with little data from low and middle income countries.11
It is possible that in developing countries different predictors of suicide ideation genesis and progression may be in operation.12,13
The development of adequate screening, prevention and intervention tools in such countries would benefit from a more in depth understanding of mental disorders as a risk factor for suicide.
There are also few data on the extent to which the associations between mental disorders and suicide attempts are mediated by suicide ideation and plans. The few studies that have investigated these issues suggest that mental disorders predict the onset of suicide ideation, but may have weaker effects in predicting suicide plans or attempts among people with suicide ideation.4,14,15
A clearer understanding of successful interventions and treatment would be achieved by mapping the relationships between identified mental disorders and progressive stages of suicide ideation – however, there is very little data to draw from in this area from the developing world.
Existing data from the South African Stress and Health Study (SASH) investigating the prevalence and correlates of suicide behaviour reveal that having a mental disorder is a risk factor for a lifetime suicide attempt. Respondents with at least one DSM–IV disorder were four times (95% CI 2.6–6.2) more likely to attempt suicide than those with no disorder.5
Respondents with three or more disorders were eight times more likely to attempt suicide (OR=8.3, 95% CI 4.8–14.2) and to develop suicidal ideation (OR=8.3, 95% CI 4.3–15.8) than were respondents with no psychiatric disorder. Here we extend that work by exploring the effects of co-occuring disorders in more detail, and by delineating the significant associations established through the mediators of suicide ideation.