Cotter and O’Keefe Myth 4: There is no good treatment for RLS A degree of therapeutic nihilism may have been justified in the past but is inexcusable with the emergence, in particular, of dopaminergic treatments for RLS. Unfortunately, many clinicians persist in using benzodiazepines, which, while sometimes effective, often cause unacceptable side effects. Others, perhaps misdiagnosing RLS as related to muscle cramps, use quinine, which has been shown to be ineffective in RLS (Van Dijk et al 1991). Why is RLS an important condition? RLS is an important condition because it is common, it causes significant distress to sufferers, it may be the presenting feature of serious underlying conditions and it is treatable. In recent years, there has been an improved understanding of the pathophysiology of the condition, particularly in relation to genetic susceptibility and to the importance of dopamine and of iron metabolism. RLS is common Ekbom performed the first study on the prevalence of RLS and reported that about 5% of a middle aged Swedish population had the condition (Ekbom 1945). However, interpretation of this and subsequent studies up to 1995 were hampered by the lack of agreed diagnostic criteria for the condition. Since then a substantial number of studies have been conducted, mainly in European and North American populations, using questions designed to elicit the essential criteria of the condition and usually requiring some minimum frequency of symptoms. As a general rule, slightly higher rates are found in studies based on self-administered questionnaires compared with studies using face-to-face or telephone interviews; the latter studies are probably more reliable. Allowing for differences in study designs and in the age and sex profile of the populations studied, there has been a remarkable consistency across different studies, with prevalence rates ranging from approximately 5% to 15%. Indeed more recent studies have converged on a range of 7%–11%. For example, a large recent French study, involving face-to-face interviews of 10 238 individuals, found a prevalence of RLS symptoms of 8.5% with a narrow confidence interval of ± 0.5% (Tison et al 2005) (Table 2). An increase in symptoms with age has been reported in most studies. For example, in an American study, Phillips and colleagues (2000) asked 1803 men and women on the telephone if they experienced symptoms of restless legs 5 or more nights per month. They received a positive response in 3% of participants aged 18 to 29, 10% aged 30 to 79 years and 19% of those aged 80 years and older. In recent years, there is increased recognition that RLS may also present during childhood; the condition may be misdiagnosed as attention-deficit/hyperactivity disorder or as ‘growing pains’ (Kotagal and Silber 1999). Another striking finding, originally reported by Ekbom (1945), is the increased frequency of the condition in women compared with men, with a two-fold difference in some reports (Rothdach et al 2000; Egan et al 2003). Associations that have been reported in population studies include links to psychiatric disorders, general health, smoking, body mass index, lower socioeconomic status, diabetes, lack of exercise, and alcohol abstinence (Phillips et al 2000). The relatively few studies in non-European populations suggest that RLS may be less common in such populations. A Turkish study found a prevalence of 3%, while a study in Singapore found that less than 1% of those questioned reported RLS symptoms (Sevim et al 2003). A Japanese study found that 1.1% reported RLS symptoms; however, contrary to the pattern in Europe, symptoms were more common in men. On the other hand, a recent Korean study Table 2 Epidemiological studies of the prevalence of Restless Legs Syndrome using International Restless Legs Syndrome (IRLS) Study Group criteria and either telephone or face-to- face interviews Year Author n Population Prevalence 1994 2000 2000 2002 2003 2005 2005 2005 2005 2005 2005 Lavigne and 2019 Canada, Montplaisir* Phillips et al** 1803 Kentucky, USA Rothdach et al 369 Germany, 65–83 years Ohayon and 18 980 Five European Roth countries Sevim et al 3234 Turkey, Allen et al 15 391 USA, 5 European countries, Högl et al 701 Bruneck, Northern Italy, 40–79 y Bjorvatn et al 2005 Norway and Denmark, Mizuno et al† 3287 Japan >65 years Tison et al 10 263 France, adults Kim et al 9930 Korea, adults 10% 10.0% 9.8% 5.5% 3.2% 7.2% 10.6% 11.5% 1.1% 8.5% 12.1% Notes: *3 of 4 IRLS criteria used for diagnosis; **2 of 4 IRLS criteria used for diagnosis; †Screening by questionnaire, followed by telephone interview. 468 Therapeutics and Clinical Risk Management 2006:2(4)