[Actigraphy in Bipolar Disorder and First Degree Relatives]

Bipolar disorder is a disabling disease that involves a significant economic costs to the health system, making it is essential to investigate possible early predictors such as changes in sleep-wake cycle in high-risk populations.

To review the available literature on alterations in the sleep-wake cycle and circadian rhythm in patients with bipolar disorder and their first degree relatives.

A literature search was performed in the data bases, Access Medicine, ClinicalKey, EMBASE, JAMA, Lilacs, OVID, Oxford Journals, ScienceDirect, SciELO, APA y PsycNET. Articles in both English and Spanish were reviewed, without limits by study type.

Actigraphy is a non-invasive, useful method for assessing sleep-wake cycle disturbances in the active phases of bipolar disorder, and during euthymia periods. Actigraphy showed good sensitivity to predict true sleep, but low specificity, compared with polysomnography. Although studies in bipolar offspring and relatives are scarce, they show sleep changes similar to bipolar patients.

Actigraphy may be a good screening tool of sleep/wake cycle in patients with bipolar disorders, because it is economic, non-invasive and sensitive. Longitudinal studies are required to evaluate its potential use as a risk marker.