Anxiety and depressive disorders in people with epilepsy: A meta-analysis

Comorbid anxiety and depressive disorders in people with epilepsy (PWE) are highly prevalent and associated with various adverse outcomes. However, the prevalence of anxiety disorders in PWE across studies is highly variable. Our aim was to estimate the prevalence and moderating factors of anxiety and depressive disorders in PWE.

Following prospective registration (PROSPERO; CRD42015027101), electronic databases were searched for studies that reported the prevalence of both anxiety and depressive disorders in samples of PWE up until July 2016. Data extracted included the prevalence of anxiety and depressive disorders, and moderators of interest (e.g., method of diagnosis, prevalence of drug-resistant epilepsy). Meta-analysis of the overall pooled prevalence of anxiety and depressive disorders was conducted.

The search yielded 8,636 unique articles, with 27 studies meeting final inclusion criteria (3,221 PWE). The pooled prevalence of anxiety and depressive disorders was 20.2% (95% confidence interval [CI] 15.3-26.0%) and 22.9% (95% CI 18.2-28.4%), respectively. Method of diagnosis significantly moderated anxiety disorder prevalence (Q statistic with one degree of freedom [Q₁ ] = 36.29, p < 0.0001); the prevalence of anxiety disorders based on unstructured clinician assessment was 8.1% (95% CI 5.7-11.4%), compared to a prevalence of 27.3% (95% CI 22.1-33.3%) based on a structured clinical interview. There were no significant moderators of depressive disorder diagnosis.

Findings suggest the prevalence of anxiety and depressive disorders in PWE are equivalent, and variability in prevalence of anxiety disorders across studies can be attributed partly to the method of diagnosis. These findings also challenge widely held assumptions that psychiatric comorbidity is more common in people with drug-resistant epilepsy. Future research should aim to improve the detection and management of these comorbidities in PWE, particularly anxiety disorders, which have remained relatively neglected.