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Prevention of depression and sleep disturbances in elderly with memory-problems by activation of the biological clock with light–a randomized clinical trial


Most, Els I. S., Scheltens, Philip, Van Someren, Eus J. W.


Trials, Volume: 11, Pages.: 19-19

Year of Publication



Background: Depression frequently occurs in the elderly and in patients suffering from dementia. Its cause is largely unknown, but several studies point to a possible contribution of circadian rhythm disturbances. Post-mortem studies on aging, dementia and depression show impaired functioning of the suprachiasmatic nucleus (SCN) which is thought to be involved in the increased prevalence of day-night rhythm perturbations in these conditions. Bright light enhances neuronal activity in the SCN. Bright light therapy has beneficial effects on rhythms and mood in institutionalized moderate to advanced demented elderly. In spite of the fact that this is a potentially safe and inexpensive treatment option, no previous clinical trial evaluated the use of long-term daily light therapy to prevent worsening of sleep-wake rhythms and depressive symptoms in early to moderately demented home-dwelling elderly.; Methods/design: This study investigates whether long-term daily bright light prevents worsening of sleep-wake rhythms and depressive symptoms in elderly people with memory complaints. Patients with early Alzheimer’s Disease (AD), Mild Cognitive Impairment (MCI) and Subjective Memory Complaints (SMC), between the ages of 50 and 75, are included in a randomized double-blind placebo-controlled trial. For the duration of two years, patients are exposed to approximately 10,000 lux in the active condition or approximately 300 lux in the placebo condition, daily, for two half-hour sessions at fixed times in the morning and evening. Neuropsychological, behavioral, physiological and endocrine measures are assessed at baseline and follow-up every five to six months.; Discussion: If bright light therapy attenuates the worsening of sleep-wake rhythms and depressive symptoms, it will provide a measure that is easy to implement in the homes of elderly people with memory complaints, to complement treatments with cholinesterase inhibitors, sleep medication or anti-depressants or as a stand-alone treatment.; Trial Registration: ISRCTN29863753.;

Bibtex Citation

@article{Most_2010, doi = {10.1186/1745-6215-11-19}, url = {}, year = 2010, month = {feb}, publisher = {Springer Nature}, volume = {11}, number = {1}, author = {Els IS Most and Philip Scheltens and Eus JW Van Someren}, title = {Prevention of depression and sleep disturbances in elderly with memory-problems by activation of the biological clock with light - a randomized clinical trial}, journal = {Trials} }


activities of daily living, adverse effects, age factors, aged, biological clocks, biological markers, blood, bright, circadian rhythm, complaints, dementia, depression, double-blind method, humans, light, memory, memory disorders, middle aged, neuropsychological tests, phototherapy, physiopathology, prevention & control, psychology, research design, rhythms, sleep disorders, sleepwake, subjective, suprachiasmatic nucleus, therapy, time factors, treatment outcome

Countries of Study


Types of Dementia

Alzheimer’s Disease, Mild Cognitive Impairment (MCI)

Types of Study

Randomised Controlled Trial

Type of Outcomes

Behaviour, Depression and Anxiety, Other, Prevention and/or management of co-morbidities


Extra Care Housing

Type of Interventions

Non-pharmacological Treatment, Treatment/prevention of co-morbidities or additional risks

Non-Pharmaceutical Interventions



Depression / Prevention Management