https://www.genengnews.com/news/brain-biomarker-predicts-compulsive-drinking/

A cortical brain circuit was identified as being “both a biomarker and a circuit-specific cellular substrate for the development of compulsive drinking.” The imaging technique is called microendoscopic single-cell resolution calcium imaging. The brain region of interest was the medial prefrontal cortex and the periaqueductal gray matter. The regions are controlling behavior and responses to adverse events, respectively. Certain neural communication patterns across the two brain regions indicated the development of compulsive alcohol drinking. This was determined by taking two mice that did not exhibit any differences in behavioral performance during their initial exposure to alcohol. After examining their neural responses from the initial exposure, the researches were able to determine the future development of compulsive drinking. This discovery has lead to the ability to shut on or off, control how much of a compulsive drinker the mice become. The scientists plan on sequencing the cortical brain stem neurons to investigate methods for therapies. 

The idea of changing a behavior through genetic therapy is bound to get people questioning the ethics of these kinds of studies. While this may actually help a population's health it can also lead to more gene therapy other types. This can be perceived as an emergence of the eugenics movement. Hopefully, it is not viewed this way because alcoholics can benefit greatly.