Bright light therapy for symptoms of anxiety and depression in focal epilepsy: randomised controlled trial

Background Bright light therapy is an effective treatment for seasonal affective disorder and non-seasonal depression. Depression and anxiety are common psychiatric comorbidities in epilepsy. Aims To examine the efficacy of bright light therapy for symptoms of anxiety and depression in adults with focal epilepsy (trial registration at ClinicalTrials.gov: NCT01028456). Method We recruited 101 adults with medically intractable focal epilepsy. Participants completed the Hospital Anxiety and Depression Scale (HADS) at the beginning (T-1) and end of a 12-week baseline period (T-2) and again after 12 weeks of daily light therapy (T-3), with 51 participants using a high-intensity light box and 50 using a low-intensity one. Seizure diaries were kept throughout the baseline and trial period. Results A total of 58 patients completed the trial. Anxiety and depression scores were significantly reduced following the light therapy at T3 in both the high- and low-intensity groups. Conclusions Light therapy resulted in a significant reduction in symptoms of anxiety and depression but we did not find any differences between high- v. low-intensity treatment. This may, therefore, be an effective treatment for symptoms of low mood in epilepsy at lower intensities than those typically used to treat seasonal affective disorder. Further work is needed to investigate this possibility with an adequate placebo condition.