Contrary to the widespread belief that depressive disorders are more common than anxiety disorders among people with epilepsy, these psychiatric comorbidities appear to have equivalent prevalence, according to research published online ahead of print May 3 in Epilepsia. In addition, variability in the observed prevalence of anxiety disorders in previous studies partly results from the method of diagnosis.
“These findings also challenge widely held assumptions that psychiatric comorbidity is more common in people with drug-resistant epilepsy,” said Amelia J. Scott, a PhD candidate at the University of Sydney.
Comorbid anxiety and depressive disorders are highly prevalent in patients with epilepsy, compared with the general population. The prevalence of anxiety disorders reported in previous studies of people with epilepsy has been highly variable, however. Ms. Scott and colleagues conducted a study to clarify the prevalence of anxiety and depressive disorders in patients with epilepsy and to determine which factors account for the variability in estimates of these disorders’ prevalence.
The investigators searched electronic databases to find studies that reported the prevalence of anxiety and depressive disorders in people with epilepsy until July 2016. Journal articles or dissertations that reported on current diagnoses of anxiety and depressive disorders based on a structured diagnostic interview or a clinician evaluation were included. Clinician evaluations followed the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition or the International Classification of Diseases, Tenth Revision or more recent.
The investigators excluded studies of participants younger than 16. In addition, studies that reported diagnoses of anxiety and depressive disorders using self-report measures and studies that only reported a depression diagnosis or only an anxiety diagnosis were also excluded. Finally, researchers excluded studies if recruitment was based on additional medical comorbidity or on results of prescreening measures of distress.
Extracted data included the prevalence of anxiety and depressive disorders and moderators of interest (eg, method of diagnosis and prevalence of drug-resistant epilepsy). Using these data, Ms. Scott and colleagues conducted a meta-analysis of the overall pooled prevalence of anxiety and depressive disorders.
In all, 27 studies met the inclusion criteria. The pooled prevalence of anxiety disorders was 20.2%, and the pooled prevalence of depressive disorders was 22.9%. Ms. Scott and colleagues also observed that the method of diagnosis significantly affected the observed prevalence of anxiety disorders. The prevalence of anxiety disorders based on unstructured clinician assessment was 8.1%, compared with a prevalence of 27.3% based on a structured clinical interview. No significant moderators of depressive disorder diagnosis were reported, however.
“Future research should aim to improve the detection and management of comorbidities in people with epilepsy, particularly anxiety disorders, which have remained relatively neglected,” said Ms. Scott. “An improvement in our understanding, detection, and management of both anxiety and depressive disorders in people with epilepsy is crucial to improve the quality of life of people with epilepsy.”
—Erica Tricarico
Suggested Reading
Scott AJ, Sharpe L, Hunt C, Gandy M. Anxiety and depressive disorders in people with epilepsy: A meta-analysis. Epilepsia. 2017 May 3 [Epub ahead of print].