title: Restless Legs Syndrome and Depression: Effect Mediation by Disturbed Sleep and Periodic Limb Movements.
abstract: To investigate an association between restless legs syndrome (RLS) and depression and to what extent sleep disturbance, periodic limb movements during sleep (PLMS), and antidepressant medication mediate this relationship.
  
  
  
  A cross-sectional analysis was conducted of the Osteoporotic Fractures in Older Men Study data in 982 men assessed for RLS (International RLS Study Group scale [IRLSS]) and depression (Geriatric Depression Scale [GDS]), who underwent actigraphy (for sleep latency/efficiency) and polysomnography (for PLMS). Men were split into three groups: no RLS (N = 815), mild RLS (IRLSS ≤ 12, N = 85), moderate-to-severe RLS (IRLSS > 12, N = 82). Depression was defined as GDS score ≥ 6. Logistic and linear regression assessed associations of RLS and depression or number depressive symptoms, respectively. Models were adjusted for age, site, race, education, body mass index, personal habits, benzodiazepine/dopaminergic medication, physical activity, cardiovascular risk factors, and apnea-hypopnea index.
  
  
  
  Of 982 men, 167 (17.0%) had RLS. Depression was significantly associated with moderate-to-severe RLS after adjustment (versus no RLS: OR [95% CI] 2.85 [1.23, 6.64]). Further adjustment for potential mediators attenuated effect size modestly, most for sleep efficiency (OR: 2.85-2.55). Compared with no RLS, moderate-to-severe RLS was associated with the number of depressive symptoms after adjustment (adjusted means [95% CI]; no RLS: 1.14 [1.05, 1.24] versus IRLSS > 12: 1.69 [1.32, 2.11]). Further adjustment for potential mediators did not alter effect size. For men with PLMS index at least median, number of depressive symptoms significantly increased as RLS category became more severe.
  
  
  
  Depression is more common as RLS severity worsens. The RLS-depression relationship is modestly explained by sleep disturbance and PLMS.
authors.affiliation: Department of Neurology, Yale University School of Medicine, New Haven, CT; Department of Neurology, Connecticut Veterans Affairs Health System, West Haven, CT; Yale Center for Neuroepidemiology & Clinical Neurological Research, New Haven, CT. Electronic address: koobri@gmail.com.
authors.forename: Brian B
authors.initials: BB
authors.lastname: Koo
authors.affiliation: California Pacific Medical Center, Research Institute, San Francisco, CA.
authors.forename: Terri
authors.initials: T
authors.lastname: Blackwell
authors.affiliation: Department Psychiatry, Yale University School of Medicine, New Haven, CT; Department of Medicine, Brigham and Women's Hospital and Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA.
authors.forename: Hochang B
authors.initials: HB
authors.lastname: Lee
authors.affiliation: California Pacific Medical Center, Research Institute, San Francisco, CA.
authors.forename: Katie L
authors.initials: KL
authors.lastname: Stone
authors.affiliation: Department of Neurology, Yale University School of Medicine, New Haven, CT; Yale Center for Neuroepidemiology & Clinical Neurological Research, New Haven, CT.
authors.forename: Elan D
authors.initials: ED
authors.lastname: Louis
authors.affiliation: Department Psychiatry, Yale University School of Medicine, New Haven, CT; Department of Medicine, Brigham and Women's Hospital and Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA.
authors.forename: Susan
authors.initials: S
authors.lastname: Redline
mesh_terms: D056044:Actigraphy; D000368:Aged; D000369:Aged, 80 and over; D000928:Antidepressive Agents / Q000627:therapeutic use; D003430:Cross-Sectional Studies; D003863:Depression / Q000188:drug therapy / Q000453:epidemiology; D003866:Depressive Disorder / Q000188:drug therapy / Q000453:epidemiology*; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D020189:Nocturnal Myoclonus Syndrome / Q000453:epidemiology*; D012148:Restless Legs Syndrome / Q000453:epidemiology*; D012720:Severity of Illness Index; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology*; D012893:Sleep Wake Disorders / Q000453:epidemiology
chemical_list: D000928:Antidepressive Agents
keywords: depression; periodic limb movement during sleep; restless legs syndrome; sleep