Sleep disorders in substance abusers: how common are they?

Substance abuse is a major public health problem with high morbidity and mortality. Comorbid disorders are suspected to cause a high relapse rate. Subjects with sleep disorders tend to self medicate with alcohol and tranquilizers to promote sleep or abuse stimulants to stay awake during the day. Substance abuse can, in turn, cause sleep disturbances, which can result in relapse. No studies have systematically studied the prevalence of various sleep disorders in these subjects. This is a cross-sectional study conducted at the Alcohol and Drug Recovery Center (ADRC) at Cleveland Clinic, Cleveland, Ohio. Subjects with active substance abuse and the ability to consent were recruited to complete a comprehensive sleep disorder questionnaire, including a general medical, psychiatric, and substance abuse history as well as validated scales (e.g., Insomnia Severity Index, Pittsburgh Sleep Quality Index (PSQI), Berlin Questionnaire for sleep apnea and restless legs). Thirty patients completed the survey so far. The most commonly abused substance was alcohol (80%) followed by narcotics (40%); about 66 percent were polysubstance users. Forty-six percent of the patients reported using substance to self-medicate sleep problems. The prevalence of various sleep disorders in this population along with the prevalence in general population in parenthesis are as follows: Sleep impairment (PSQI>5) was noted in 96 percent (15%) of the subjects, and 56 percent (10-15%) had insomnia of moderate-to-severe degree. Symptoms suggestive of sleep apnea were reported in 53 percent (4-6%) of the subjects and restless leg syndrome symptoms in 33 percent (10%). Substance abuse is on the rise and affects every aspect of society. Our study has, for the first time, systematically evaluated various sleep disorders in these subjects who seem 5 to 10 times more likely to have sleep disorders. Diagnosing and treating sleep disorders will have a huge impact in inducing remission. However, this study has significant limitations, including a small number of subjects, subjective data collected via questionnaires, and no long-term follow up, which makes it difficult to draw conclusions.