Korean J Biol Psychiatry.  2014 Aug;21(3):107-113.

Clinical Significance of Restless Legs Syndrome in Patients with Late Life Depression

• Song JM
• Park JH
• Kang JE
• Lee CI

Abstract

OBJECTIVES
Restless legs syndrome (RLS) is a sleep disorder characterized by uncomfortable and unpleasant sensations in the legs and an urge to move the legs, usually at night. The aim of this study is to investigate the incidence of RLS in patients with late life depression and its influence on various clinical outcomes such as severity of depression, sleep quality, cognitive function, and quality of life and accordingly, to elucidate the clinical significance of RLS in patients with late life depression (LLD).
METHODS
This study enlisted 170 depressive patients aged 65 years or older from an outpatient clinic. Structured diagnostic interviews were performed using the Korean version of the Mini-International Neuropsychiatric Interview. All patients completed the questionnaires, including the International RLS Severity Scale, the Korean version of Short-Form 36-Item Health Survey (SF-36), and the Pittsburgh Sleep Quality Index (PSQI). The severity of depression was evaluated by the Korean form of the Geriatric Depression Scale (KGDS) and the level of global cognition was assessed by the Mini-Mental State Examination in the Korean version of The Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (MMSE-KC).
RESULTS
The incidence of RLS was 17.6% in LLD patients. RLS was more prevalent among the subjects with major depressive disorder (MDD) than those with minor depressive disorder or subsyndromal depressive disorder. The RLS group showed higher score in the KGDS than the Non-RLS group but the difference did not reach the statistical significance (p = 0.095, Student t-test). The mean PSQI score was significantly higher in the RLS group than in the Non-RLS group (p = 0.001, Student t-test). The MMSE-KC score was also lower in the RLS group than in Non-RLS group (p = 0.009, analysis of covariance). But, there was no difference in the score of SF-36 between the RLS group and the Non-RLS group.
CONCLUSIONS
RLS is common in LLD patients, especially in the patients with MDD and is associated with poor sleep quality and cognitive dysfunction, indicating that RLS is clinically significant in patients with LLD. Therefore, RLS should be considered as an important clinical issue in the management of LLD.

Keyword

Restless legs syndrome; Late life depression; Sleep quality; Cognitive function; Quality of life