Abstract
INTRODUCTION: This study aims to clarify differences in mood, craving, and treatment response between reward and relief/habit individuals in a study of naltrexone, varenicline, and placebo. We hypothesized that relief/habit individuals would have a poorer mood during early abstinence and higher levels of alcohol craving than reward individuals. We hypothesized that reward individuals would demonstrate better drinking outcomes on naltrexone versus placebo. METHODS: Data were culled from a randomized, double-blind, placebo-controlled human trial of 53 individuals (18F/16M) with alcohol use disorder randomized to varenicline (n = 19), naltrexone (n = 15), or matched placebo (n = 19). In this 6-day practice quit trial, participants attempted to abstain from drinking and completed daily diaries. Participants were classified into reward or relief/habit subgroups based on self-reported motivation for drinking. Multilinear models tested differences in mood and alcohol craving between reward and relief/habit individuals. General linear models tested differences between reward and relief/habit individuals' drinking outcomes on each medication versus placebo. RESULTS: Relief/habit individuals showed decreases in positive mood and increases in negative mood over the quit attempt across medications, compared to reward individuals (P's < .05). Reward individuals' tension decreased on naltrexone, while relief/habit individuals' tension remained stable (F = 3.64, P = .03). Reward individuals in the placebo group had higher percent days abstinent than relief individuals in the placebo group (P < .001). DISCUSSION: This study suggests relief/habit individuals' mood worsens during early abstinence. Our finding that reward individuals' tension decreased on naltrexone and increased on placebo may suggest a clinical response to the medication.