A randomized, controlled trial of bright light therapy for agitated behaviors in dementia patients residing in long-term care

Int J Geriatr Psychiatry. 1999 Jul;14(7):520-5.


Background: Agitated behaviors are common in dementia patients residing in chronic care settings. Their occurrence may be associated with lack of adequate exposure to sunlight and with circadian rhythm disturbances.

Objective: Prior research has suggested that bright light therapy (BLT) may reduce agitated behaviors in dementia patients. The aim of this study was to test the efficacy of BLT in a randomized, controlled, crossover clinical trial.

Method: Fifteen patients with dementia and agitated behaviors residing in a chronic care facility were randomized in a crossover design to morning BLT for 1 hour per day or to a control condition with dim light exposure. Patients were treated in either condition for 4 weeks, followed by 1 week on no treatment, prior to being crossed over to the other condition.

Results: Eight out of 15 patients completed the entire study. The rest completed at least 2 weeks of study. Patients randomized to the BLT condition exhibited a statistically significant improvement in nocturnal sleep from a mean of 6.4 hours/night to 8.1 hours/night 4 weeks later (p<0.05). The sleep of patients in the control condition did not improve significantly. There were no other significant differences between baseline and follow-up, nor between BLT and control treated patients on the other outcome measures, which included the Behavioral Pathology in Alzheimer Disease scale (Behave-AD) and the Cornell Scale for Depression in Dementia.

Conclusion: Patients with dementia in chronic care who exhibit agitated behaviors sleep more hours at night when administered morning BLT. However, BLT does not lead to improvements in agitated behaviors in institutionalized patients with dementia with non-disturbed sleep-wake cycles.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Cross-Over Studies
  • Dementia / complications*
  • Female
  • Humans
  • Male
  • Nursing Homes
  • Phototherapy*
  • Psychomotor Agitation / etiology
  • Psychomotor Agitation / therapy*
  • Sleep Wake Disorders / etiology
  • Sleep Wake Disorders / therapy*
  • Treatment Outcome