Research Update

Research Date

In clinical trials for alcohol use disorder (AUD), abstinence and no heavy drinking days are currently the only end points approved by the U.S. Food and Drug Administration. However, many individuals who do not achieve these end points may still reduce their drinking to less harmful levels during treatment.

A recent study published in Alcoholism: Clinical and Experimental Research suggests that reductions in drinking risk levels could be useful end points for evaluating the effectiveness of AUD treatment for a given patient. Researchers conducted a secondary analysis of data collected from more than 1,000 individuals enrolled in NIAAA’s Combined Pharmacotherapies and Behavioral Interventions study, also known as COMBINE. The COMBINE study, a clinical trial of medications and behavioral treatments for fourth edition Diagnostic and Statistical Manual of Mental Disorders alcohol dependence (as defined in the Diagnostic and Statistical Manual of Mental Disorders, fourth edition) launched in 2001 and was conducted at 11 academic sites throughout the United States.

Researchers examined the COMBINE data for associations between reductions in drinking risk levels established by the World Health Organization (WHO) and improvements in physical health and quality of life.

WHO defines four levels of drinking risk, from low risk to medium, high, and very high risk.

A table of four levels of driking risk from WHO

The researchers found that during treatment, reductions of one and two levels of WHO drinking risk (for example, reducing alcohol consumption from high risk to medium or low risk) were associated with significant reductions in blood pressure, improvements in liver enzyme levels, and significantly better quality of life measures. The researchers concluded that their findings suggest a reduction in WHO drinking risk levels could be a meaningful surrogate marker of improvement in how a person “feels and functions” after AUD treatment. They also note that “extending treatment options to target reductions in drinking, rather than complete abstinence, could expand the reach of alcohol treatment and have an important impact on public health.”


Witkiewitz, K.; Kranzler, H.R.; Hallgren, K.A.; O’Malley, S.S.; Falk, D.E.; Litten, R.Z.; Hasin, D.S.; Mann, K.F.; and Anton, R.F. Drinking risk level reductions associated with improvements in physical health and quality of life among individuals with alcohol use disorder. Alcoholism: Clinical and Experimental Research42(12):2453–2465, 2018. PMID: 30395350

This article first appeared in the NIAAA Spectrum.