Do depression and anxiety converge or diverge in their association with suicidality?

Depressive disorders have been strongly linked to suicidality, but the association with anxiety disorders is less well established. This exploratory study aims to examine whether anxiety and depressive disorders are both independent risk factors for suicidal ideation and attempted suicide, and additionally examined the role of specific clinical characteristics (disorder type, severity, duration, onset age) in suicidality. Data are from 1693 persons with a current (6-month) CIDI based depressive or anxiety disorder and 644 healthy controls participating in the baseline measurement of the Netherlands Study of Depression and Anxiety, which is an existing dataset. Suicidal ideation in the week prior to baseline and attempted suicide ever in life were assessed. Results showed that compared to persons with only an anxiety disorder, persons with a depressive disorder were at significantly higher risk to have current suicidal ideation or a history of attempted suicide. When examining the association between type of disorder and suicidality the odds ratio for MDD was significantly higher than those for the separate anxiety disorders. Although depression and anxiety severity were univariate risk indicators for suicidal ideation and attempted suicide, only depression severity remained a risk indicator for suicidal ideation and attempted suicide in multivariate analyses. Additional risk indicators were an early age at disorder onset for both suicidal ideation and attempted suicide, male gender for suicidal ideation and lower education for attempted suicide. These findings suggest that although anxiety and depression tend to converge in many important areas, they appear to diverge with respect to suicidality.