Obsessive compulsive disorder (OCD) is a severe, often long-term mental disorder. It may be independent from, or comorbid with other mental disorders, especially depression and anxiety disorders. Suicidal thoughts, ideations and ruminations are prevalent in subjects with OCD, but it is not yet clear if the incidences of attempted and completed suicides have increased in comparison with the general population and with other psychiatric disorders.
We conducted a systematic literature search on the incidence of suicide attempts and completed suicides in subjects with OCD. Search terms for Pubmed and Medline were OCD and suicide. We selected papers providing follow-up data on the incidence of attempted and completed suicide in OCD.
404 papers were initially identified. Only 8 papers covering six studies provided prospective data on attempted or completed suicide over a defined period in subjects with OCD, four studies included control subjects. Two studies providing follow-up data were limited to high-risk samples and did not provide enough data on the incidence of suicide in comparison with the general population. The conclusion that there is an increased risk of attempted and completed suicides in OCD can only be based on one large Swedish National Registry sample with an up to 44 year follow up. Psychiatric comorbidity is the most relevant risk factor for suicide.
Even though some studies report an increased incidence of attempted and completed suicides in OCD patients from selected high risk samples, the evidence from population based studies is mostly based on one large Swedish study. More long-term studies in the general population with a reduced risk of subject attrition are needed. Using a clear definition and assessment of suicidal behaviour and a common time-frame would improve the comparability of future studies.