105 Therefore, RLS and PLMD are distinct by definition, but may coexist. A recent study found that several polysomnographic features in RLS differ from those of PLMD,106 suggesting that different pathophysiological mechanisms may influence sleep in both conditions. RLS and PLMD are highly prevalent. RLS is found in 9% to 15% of adults107,108 and its prevalence increases with age. PLMS may occur in up to 6% of the general population109 and in 20% of patients aged 60 years or older.110 The unpleasant sensations experienced by patients with RLS Inhibitors,research,lifescience,medical often lead to noticeable loss of sleep, with the more severely affected patients sleeping no more than 4 to 5 h and experiencing deficits in daily functioning.

Patients also report problems with functioning in sedentary situations, particularly in physically constraining places, and also in the evening when the symptoms are usually exacerbated. As a result, patients may have problems accomplishing their jobs and participating in social and recreational activities.111 Symptoms, along with the impairment Inhibitors,research,lifescience,medical of sleep,

may cause distress Inhibitors,research,lifescience,medical and lead to psychiatric illness and decreased well-being. In the 19th century, Wittmaack described the cooccurrence of RLS with symptoms of depression and anxiety, and suggested the term “anxietas Mdm2 inhibitor tibiarum.”112 Although the first modern study attracting attention to psychiatric comorbidity, showing higher scores on depression and psychoasthenia in RLS patients, was performed 40 years ago,113 little progress has been made since then in attempts to explore this relationship. Despite their high prevalence in the general population, little information is available on the impact of PLMS or RLS on quality Inhibitors,research,lifescience,medical of life. In a recent American Academy of Sleep Medicine review, reference is made to the “striking omission” of quality of life research Inhibitors,research,lifescience,medical and psychological impact with respect to this disorder.114 In two drug trials utilizing a modified version

of the Hamburg Visual Analog Scales, improvements after dopaminergic treatment (first-line therapy for RLS) were noted in activities of daily living, mental function, fatigue, and depressive feelings.115,116 A more recent large survey suggested a substantial impact of RLS on quality of life equivalent to or worse than some other major chronic medical disorders.117 This impact was apparent on all of the SF-36 items, but the more pronounced during deficits occur for measures of vitality/energy and limitations of work and activities due to physical problems, suggesting a major decrease in the level of alertness and energetic engagement with daily function. The data also indicate that patients with RLS are likely to have problems with anxiety or depressed feelings. This is in accordance with other data suggesting that patients with RLS are likely to experience mental health problems.