Ibudilast and Withdrawal-Related Dysphoria

Alcohol use disorder (AUD) is a prevalent and disabling psychiatric disorder with few, and only moderately efficacious, treatment options. Consequently, the identification of novel treatment targets and the development of rigorous laboratory paradigms to screen and optimize novel therapeutics represents a research priority. Ibudilast (IBUD) is a neuroimmune modulator that inhibits phosphodiesterase-4 and -10 and macrophage migration inhibitory factor. Recently in an AUD sample, IBUD was shown to decrease reactivity to a psychological stressor. Furthermore, IBUD was effective in blunting alcohol reward among participants with greater depressive symptoms, a hallmark symptom of protracted withdrawal. Recently, preclinical research in opiates has demonstrated that drug withdrawal is necessary for microglia activation and neuroinflammation in reward networks, suggesting that IBUD may be most effective among patients who experience withdrawal-related dysphoria. Therefore, this proposed study aims to examine withdrawal-related dysphoria as a moderator of IBUD efficacy in the natural environment measured using Daily Diary Assessment (DDA) approaches. To accomplish this aim, participants meeting criteria for AUD and balanced on the presence of withdrawal-related dysphoria will be enrolled in a double-blinded IBUD trial including consisting of two weeks randomized to medication and DDA assessment. The proposed research aims are: Aim 1: Test whether IBUD reduces basal negative affect in abstinence, and blunts alcohol-related negative reinforcement. It is hypothesized that IBUD will reduce basal levels of negative affect during alcohol abstinence, and in so doing will interfere with alcohol-induced blunting of negative affectivity as captured during naturalistic drinking episodes. Aim 2: Test whether IBUD attenuates neural alcohol cue-reactivity. It is hypothesized that IBUD will reduce BOLD activation to alcohol cues in mesocorticolimbic reward circuitry. Aim 3: Test whether withdrawal-related dysphoria moderates the effects of IBUD. It is hypothesized that IBUD will alleviate basal negative affect, interfere with alcohol-induced negative reinforcement and attenuate BOLD activation to alcohol cues only among participants who experience dysphoria in withdrawal. Aim 4: Test whether neural activation to alcohol cues is predictive of drinking outcomes. It is hypothesized that individuals with higher mesocorticolimbic activation to alcohol cues will report more drinking in the week following the neuroimaging session.