Newswise — A study published in Alcoholism: Clinical and Experimental Research provides support for treatment goals based on reducing drinking, and not necessarily stopping completely, for people recovering from alcohol use disorder (AUD). AUD is linked to damaging reductions in the gray and white matter of certain brain regions. This tissue loss, particularly in the frontal brain lobes, can contribute to cognitive deficits and may increase the risk of relapse following treatment. In people with AUD who quit alcohol completely, brain tissue volumes can increase quite dramatically during abstinence, in parallel to cognitive improvements. Complete abstinence is also associated with improvements in general health and quality of life - therefore abstinence is the usual goal of treatment for AUD.

However, many treatment seekers struggle with the expectation of complete abstinence, and may be better motivated to get treatment by a goal of drinking reduction.Recent evidence suggested that cutting down is associated with meaningful improvements in physical and psychosocial outcomes. Attention among treatment experts has thus turned towards non-abstinent treatment goals, and towards identifying a level of drinking reduction that – similar to total abstinence – is associated with beneficial regional brain tissue volumes in those who cannot maintain abstinence (relapsers). In the new study, researchers from the University of California have used MRI data to compare regional brain volumes among abstainers and two groups of relapsers - with low and higher levels of alcohol intake - following treatment.

The data were from adults with diagnosed AUD, who had consumed an average of ~15 standard drinks per day over the previous year and initiated treatment at an outpatient clinic. Eight months after starting treatment, participants completed a detailed ‘follow-back’ interview to assess their pattern of drinking over that interval. Those reporting no drinking were classed as abstainers. Those who reported some alcohol use (or had medical records indicating relapse) were classed as relapsers and assigned to one of four World Health Organization (WHO) risk drinking levels (very high, high, moderate and low) based on their daily alcohol consumption averaged over the recovery period. An MRI scan was conducted at the same timepoint after the 8-months-interval, to assess volumes of gray matter in select, alcohol-relevant brain regions.

Data from 28 relapsers and 26 abstainers, who were well matched on demographic and other characteristics, were evaluated. Seventeen of the relapsers had a ‘low’ WHO risk level at follow-up – i.e. they had reduced their drinking to a level equating to an average of no more than ~3 standard drinks (for men) or ~1.5  standard drinks (women) per day. Eleven relapsers had an average daily consumption above this threshold, and they were assigned to a higher WHO risk level at follow-up. Statistical analysis showed that relapsers with a low risk level had regional brain tissue volumes indistinguishable from those of abstainers at follow-up. However, those with higher risk levels had significantly smaller gray matter volumes in relevant brain regions than abstainers and low-risk level relapsers. Low (versus higher) risk level relapsers also tended to perform better on cognitive domains of working memory and visuospatial skills assessed over the recovery interval.

This is one of the first studies to relate reduced drinking (as opposed to complete abstinence), after treatment for AUD, to objective measures of brain health and cognitive improvement. As such, the findings provide further support for clinically meaningful drinking reduction goals, which is of practical relevance to patients, treatment providers, and clinical researchers. The study also highlights structural MRI measures that may have a role as biomarkers of treatment response and brain health for future clinical trials.

Not all is lost for relapsers: Relapsers with low WHO risk drinking levels and complete abstainers have comparable regional gray matter volumes. D.J. Meyerhoff, T.C. Durazzo (pages xxx)