Abstracts

Rationale: Bright Light Therapy (BLT) influences the regulation of melatonin and is an established treatment for seasonal affective disorder (SAD). It is also an effective treatment for non seasonal depression in some patients. Depression and anxiety are amongst the most common psychiatric co-morbidities in epilepsy, with epidemiological studies suggesting a bi-directional relationship. This randomised control trial was designed to examine the efficacy of BLT for symptoms of anxiety and depression in adults with focal epilepsy . Methods: 101 adults with medically intractable, focal epilepsy were recruited to a parallel design, double blind, randomized trial of BLT. Participants completed the Hospital Anxiety and Depression Scale (HADS) at the beginning (T1) and end of a 12 week baseline period (T2). 51 of the participants were allocated a high intensity light box emitting 10,000 lux using an automated permuted block randomisation grid; 50 were allocated a cosmetically identical box emitting 2,000 lux (low intensity), a sub therapeutic dose in other patient populations. Both groups were instructed to use their box for 20-30 minutes, upon waking every day for 12 weeks. Following the end of the trial the participants completed the HADS for a third time (T3). Results: 60 participants (31 high intensity/29 low intensity) completed the trial and returned adequate data for analyses. Anxiety scores were significantly reduced following the BLT at T3 compared to the baseline measurements (T1 & T2) in both the high and low intensity groups. The same pattern was evident in the depression data with depression scores significantly reduced following the BLT at T3 compared to the baseline measurements (T1 & T2) in both the high and low intensity groups. Conclusions: We did not find any differences between the high vs. low intensity bright light therapy groups on self reported symptoms of anxiety and depression. Both groups reported a significant reduction in symptoms following treatment. BLT may be an effective treatment for symptoms of low mood in epilepsy at lower intensities than those typically used to treat SAD. Further work is needed to investigate this hypothesis with an adequate placebo condition. Trial Registration: www.ClinicalTrials.gov. Registration number NCT01028456. Source of Funding: This study was funded by a research grant number AP1202 from Action Medical Research, UK.