Comorbidity and Suicidality in Patients Diagnosed with Panic Disorder/Agoraphobia and Major Depression

Comorbidity of anxiety and depression (both current and lifetime) is associated with greater chronicity and an increased risk of suicidality. We wished to ascertain which symptom clusters had the strongest association with suicidality. Our aims were (1) to examine the presence of current comorbidity and suicidality in patients diagnosed with panic disorder/agoraphobia (PD/A) and major depression (MD), and their relationship with duration of psychiatric treatment and frequency of hospital admission; and (2) to examine which coexisting symptoms were most strongly predictive of suicidality in sub-groups and the overall group.

The study sample comprised 100 patients with PD/A and MD. The following assessment instruments were applied: the Panic and Agoraphobia Scale, the Beck Anxiety Inventory, the Beck Depression Inventory-II, the Beck Scale for Suicide Ideation, the Obsessive-Compulsive Inventory-Revised, the Liebowitz Social Anxiety Scale and the Whiteley Index of Hypochondriasis.

High rates of current comorbidity were seen in both groups. Patients with MD had significantly higher suicidality scores, but were also older, with a longer duration of psychiatric treatment and more frequent hospitalizations. In the overall group, psychiatric comorbidity was correlated with duration of psychiatric treatment and frequency of hospitalizations (with the exception of hypochondriasis which was not correlated with frequency of hospitalization). In both sub-groups and the overall group, suicidality was correlated with scores for all examined comorbidity (with the exception of hypochondriasis in the PD/A group): however, after multiple regression only obsessive-compulsive symptomatology predicted suicidality in all sub-groups and the overall group, as well as depression in the overall group. Depression supposed as dependent variable and obsessive-compulsive symptomatology as a mediator explained around 37% of the variance in suicidal ideation.

Patients with PD/A or MD show high rates of current comorbidity. The effect of depression on suicidality was significant, but a non-trivial impact was also mediated by obsessive-compulsive symptomatology.