Addict Biol. 2022 May;27(3):e13165. doi: 10.1111/adb.13165.
This study investigated the potential therapeutic effects of the FDA-approved drug metformin on cue-induced reinstatement of cocaine seeking. Metformin (dimethyl-biguanide) is a first-line treatment for type II diabetes that, among other mechanisms, is involved in the activation of adenosine monophosphate activated protein kinase (AMPK). Cocaine self-administration and extinction is associated with decreased levels of phosphorylated AMPK within the nucleus accumbens core (NAcore). Previously, it was shown that increasing AMPK activity in the NAcore decreased cue-induced reinstatement of cocaine seeking. Decreasing AMPK activity produced the opposite effect. The goal of the present study was to determine if metformin in the NAcore reduces cue-induced cocaine seeking in adult male and female Sprague Dawley rats. Rats were trained to self-administer cocaine followed by extinction prior to cue-induced reinstatement trials. Metformin microinjected in the NAcore attenuated cue-induced reinstatement in male and female rats. Importantly, metformin's effects on cocaine seeking were not due to a general depression of spontaneous locomotor activity. In female rats, metformin's effects did generalize to a reduction in cue-induced reinstatement of sucrose seeking. These data support a potential role for metformin as a pharmacotherapy for cocaine use disorder but warrant caution given the potential for metformin's effects to generalize to a natural reward in female rats.
Gender Differences in the Psychosocial Determinants Underlying the Onset and Maintenance of Alcohol Use Disorder
Front Neurosci. 2022 Mar 14;16:808776. doi: 10.3389/fnins.2022.808776. eCollection 2022.
A large number of different mechanisms have been linked to Alcohol Use Disorder (AUD), including psychosocial, neurocognitive, affective, and neurobiological factors. Gender has been shown to impact the presentation and progression of AUD; yet, little work has been done to parse the different mechanisms underlying AUD within the lens of gender differences. A review of the literature on adolescence revealed that psychosocial factors, in particular lack of family social support and interactions with peers, drive the onset of alcohol use more strongly in girls relative to boys. However, research done on gender differences in disease progression in adults remains limited. Our gender-specific analysis of the mechanisms underlying AUD in adults revealed that lack of social support was causally linked to negative affect, mental health symptoms, and AUD symptom severity in women, but not men. These novel results suggest that psychosocial factors may play a gender-specific role not only in the onset of use in adolescence, but also in the maintenance of addiction in adults. If confirmed, this suggests the need for investigating gender-specific recovery trajectories. In this perspective piece, we review the literature regarding gender differences in the onset and maintenance of AUD and present original data that support unique risk factors in women.