Bright light therapy for negative symptoms in schizophrenia: a pilot study.
Sir: Negative symptoms like blunted affect, lack of spontaneity , and emotional and social withdrawal are disabling conditions for many schizophrenic patients. Pharmacologic strategies alone are frequently insufficient in the treatment of negative symptoms. New treatment approaches are therefore required. Bright light therapy is the treatment of choice for seasonal depression , but is now also shown to be efficacious in nonseasonal depression. 1 Until now, no studies of bright light therapy in schizophrenic patients have been published. This is the first study to evaluate the safety and tolerability of bright light therapy in patients diagnosed with the residual subtype of schizophrenia. Method. Ten patients (8 men and 2 women) with a diagnosis of schizophrenia (DSM-IV criteria) were included in the study, which was conducted from January 2001 to October 2003. At study entry, the mean age of all patients was 41.8 years. Inclusion criteria were residual subtype of schizophrenia (295.6) and stable antipsychotic medication treatment for at least 4 weeks. Antidepressants were not allowed, and any medication inducing photosensitivity was an exclusion criterion. All patients signed informed consent statements before they were enrolled in the study, and the study was approved by the local human subjects research committee. Bright light therapy with 10,000 lux (Chronolux CL–100; Samarit; Aachen, Germany) was applied 1 hour daily, 5 days a week, for 4 weeks. All patients were evaluated with the Positive and Negative Syndrome Scale (PANSS), 2 a visual analog scale (VAS) for mood and a VAS for drive (ranging from 0 mm [abso-lute best mood or drive] to 100 mm [absolute worst mood or drive]), the Clinical Global Impressions scale (CGI), 3 and the Hamilton Rating Scale for Depression (17 items). 4 Measurements were conducted by blinded raters at the screening visit and at weeks 1, 2, and 4, and follow-up examinations were conducted at weeks 8 and 12. Statistical analyses were conducted using SPSS, Version 12 (SPSS Inc.; Chicago, Ill.). The effect of light therapy on the time course of the outcome variables listed above was tested with the Friedman test, as the assumption of normality was not met. Post hoc comparisons between individual time points were performed using the Wilcoxon test. During the treatment period (weeks 1–4), patients were analyzed by an intent-to-treat method, replacing missing data by the last-observation-carried-forward method. Results. Nine patients concluded 4 weeks of treatment, and 1 patient discontinued after 2 weeks for personal reasons. …