Psychological factors associated with NAFLD/NASH: a systematic review.

Nonalcoholic fatty liver disease (NAFLD) represents one of the most common chronic liver diseases worldwide. So far, the pathogenesis of NAFLD and its more severe variant nonalcoholic steatohepatitis (NASH) is yet unclear, with many mechanisms being proposed as possible causes. This article aims to review the psychological factors associated with NAFLD/NASH.Three main categories of factors have been investigated: emotional, cognitive and behavioral. Five electronic databases were searched, limited to studies published in the English language, during the period 2005-2015: PubMed, Thomson ISI - Web of Science, Scopus, ProQuest, and ScienceDirect.Results indicated the most relevant emotional factors to be depression and anxiety. The areas of investigation for cognitive functioning concern those contents and processes related to the ability to initiate and maintain lifestyle changes. The most important behavioral factors identified are physical activity, nutrition/food intake and substance consumption: coffee, alcohol, cigarettes.Some of the factors identified act as protective factors, other as vulnerability factors. NAFLD/NASH may be considered a cognitive-behavioral disease, the most effective management being lifestyle changes, with emphasis on diet and exercise.