Comorbid Substance Use and Eating Disorders

Substance use disorders can affect from 25% to 50% of ED patients.

Many people with substance use disorders (SUDs) do not seek treatment, and many, perhaps the majority, relapse. One factor underlying relapse is the presence of a comorbid eating disorder, according to psychologist Dr. JoAnna Elmquist of the University of Tennessee, Knoxville. This comorbidity often leads to poorer treatment outcomes, higher risk for relapse, and higher mortality.

Dr. Elmquist and colleagues at Ohio University, UTM, and Cornerstone of Recovery, an alcohol and substance abuse treatment center in Louisville, TN, recently evaluated the possible relationships between bulimia and binge-eating symptoms and rejection of treatment among a group of young men at a residential substance use treatment center (Subst Abuse. 2016; 10:39).

According to the authors, estimates of comorbid EDs and SUDs are alarmingly high: for example, the prevalence of EDs among patients seeking treatment for SUDs is 35%, far higher than the prevalence of EDs in the general population (BMC Psychiatry. 2013; 13:289). Correspondingly, many of those with EDs also have a diagnosis of an SUD. The high co-occurrence of EDs and SUDs has been suggested to be due to use of alcohol and/or drugs to suppress appetite, leading to disordered eating and problematic substance use. Additionally, heavy drinking (5 or more drinks at one session, for men) may be followed by severe caloric restriction to compensate for the alcohol calories. The authors also note that personality factors such as impulsivity might explain the high comorbidity.

The authors used medical records of 68 men aged 18 to 25 who were undergoing 28 to 35 days of treatment at a 12-step residential center. Bulimia and binge eating symptoms were assessed with the 10-item ED subscale of the Psychiatric Diagnostic Screening Questionnaire (Los Angeles: Western Psychological Services, 2002). The 22-item depression subscale on the same questionnaire was used to assess the presence of depression in the men. To assess treatment rejection, the authors used the 8-item treatment rejection (RXR) subscale of the Personality Assessment Inventory. This subscale assesses such components of treatment nonadherence as lack of motivation and unwillingness to accept responsibility for one’s actions. Two other measures, the 10-item Alcohol Use Disorders Identification Test (AUDIT) and the 14-item Drug Use Identification Test were used to measure alcohol use and problems and drug use and problems over the past year.

What the authors found

Dr. Elmquist and colleagues reported that alcohol use was significantly and negatively associated with treatment rejection, but positively associated with ED symptoms. Alcohol use was negatively associated with drug use, and drug use was significantly associated with depression symptoms; in turn, treatment rejection was negatively associated with depression symptoms.

Where did all this leave the research team? Rejection of treatment was associated with ED symptoms after controlling for alcohol and drug use and problems with depressive symptoms. The authors speculate that traits such as impulsivity or difficulties with distress tolerance may explain the findings. They correctly note that the findings emphasize the importance of identifying strategies that address both SUDs and EDs.