The effects of light therapy on mini-mental state examination scores in demented patients

Background: Preliminary evidence suggests that demented patients may experi ence beneficial effects of light therapy. The authors tested whether bright light therapy (BLT) is capable of improving cognitive functions in patient s with Alzheimer-type dementia (AD) or vascular dementia (VD). Methods: Twenty-three patients with AD or VD were randomly assigned to eith er evening BLT or dim light therapy (DLT). Effects of light therapy on cogn itive functions were assessed before and after light therapy using Mini-Men tal State Examination (MUSE) scores. Body temperature rhythm (BTR) was addi tionally recorded pre- and posttreatment. Results: Irrespective of their diagnosis, patients treated with BLT (p =.00 12) but not with DLT (p =.73) showed a statistically significant increase i n MMSE total scores after light therapy. Evening BLT simultaneously induced a significant phase delay of 56 min on BTR (p =.025). Conclusions: Our preliminary results suggest that shortterm evening BLT may exert beneficial effects on cognitive functioning in patients with dementi a. 2001 Society of Biological Psychiatry.