Depression and anxiety in epilepsy: the association with demographic and seizure-related variables

Abstract

Background: Depression and anxiety are common psychiatric symptoms in patients with epilepsy, exerting a profound negative effect on health-related quality of life. Several issues, however, pertaining to their association with psychosocial, seizure-related and medication factors, remain controversial. Accordingly, the present study was designed to investigate the association of interictal mood disorders with various demographic and seizure-related variables in patients with newly-diagnosed and chronic epilepsy.

Methods: We investigated 201 patients with epilepsy (51.2% males, mean age 33.2 +/- 10.0 years, range 16-60) with a mean disease duration of 13.9 +/- 9.5 years. Depression and anxiety were assessed in the interictal state with the Beck Depression Inventory, 21-item version (BDI-21) and the state and trait subscales of the State-Trait Anxiety Inventory (STAI-S and STAI-T), respectively. The association of mood disorders with various variables was investigated with simple and multiple linear regression analyses.

Results: High seizure frequency and symptomatic focal epilepsy (SFE) were independent determinants of depression, together accounting for 12.4% of the variation of the BDI-21. The STAI-S index was significantly associated with the type of epilepsy syndrome (SFE). Finally, high seizure frequency, SFE and female gender were independent determinants of trait anxiety accounting for 14.7% of the variation of the STAI-T.

Conclusion: Our results confirm the prevailing view that depression and anxiety are common psychological disorders in epileptics. It is additionally concluded that female gender, high seizure frequency and a symptomatic epilepsy syndrome are independent risk factors for the development of anxiety and/or depression.

Figure 1

Scattergram demonstrating the relationship between BDI score and the type of epilepsy syndrome. SFE: symptomatic focal epilepsy, CFE: cryptogenic focal epilepsy, IGE: idiopathic generalized epilepsy. A linear regression line and the 95% confidence band are shown. Slope: -2.299 ± 0.6290 (95% confidence interval: -3.532 to -1.066); y-intercept: 11.50 ± 1.182 (95% CI: 9.187 to 13.82); p < 0.001.

Figure 2

Scattergram demonstrating the relationship between STAI-2 score and the type of epilepsy syndrome. SFE: symptomatic focal epilepsy, CFE: cryptogenic focal epilepsy, IGE: idiopathic generalized epilepsy. A linear regression line and the 95% confidence band are shown. Slope: -1.932 ± 0.5797 (95% confidence interval: -3.068 to -0.7957); y-intercept: 46.16 ± 1.090 (95% CI: 44.03 to 48.30); p < 0.001.