Therapy for Insomnia and Circadian Rhythm Disorder in Alzheimer Disease

There is strong evidence for a bidirectional association between sleep disorders and Alzheimer's disease (AD). In particular, insomnia may be a potentially modifiable risk factor for AD. The present review summarizes recent advances in treatment of sleep disorders in AD.

Some studies investigated the efficacy and safety of hypnotic agents as ramelteon and mirtazapine to treat sleep disorders in AD but no significant therapeutic effects have been observed. Benzodiazepines are the most frequently used medication for treatment of insomnia but they may cause significant side effects in old subjects. Suvorexant, an orexin receptor antagonist, showed a positive effect on AD insomnia. Recent report suggests an association between trazodone use and delayed cognitive decline in AD. With respect to circadian rhythm disorders, non-pharmacological treatments, especially bright light therapy, could be useful and safe options for treatment in AD. Some pharmacological and non-pharmacological treatments might have benefits in AD patients with sleep disturbances, but further well-designed controlled trials are needed.