The present study demonstrates that chronic administration of cannabidiol (CBD) attenuates both behavioral and neurobiological manifestations of alcohol dependence in rodent models. Specifically, CBD reduced alcohol intake and withdrawal symptoms, lowered relapse-like behaviors, normalized neuronal excitability in the basolateral amygdala (BLA), and prevented alcohol-induced neurodegeneration in striatal regions associated with reward and habit formation. Additionally, CBD did not potentiate alcohol’s sedative effects, as shown by no differences in loss of righting reflex duration or locomotor activity during alcohol intoxication, while increasing time spent in the open field’s center, indicating anxiolytic effects. These results underscore CBD’s potential therapeutic utility for alcohol use disorder (AUD) and provide mechanistic insights into its actions.

Chronic intermittent ethanol (CIE) exposure is a well-established model that induces physical dependence and mimics the neuroadaptive changes observed in human AUD, particularly during withdrawal [25–30]. In this study, CBD administration during CIE exposure significantly reduced alcohol intake during acute withdrawal without affecting alcohol metabolism or locomotor activity. This aligns with earlier findings that CBD decreases ethanol intake and motivation to drink in rodent models [13–15]. Importantly, CBD also alleviated withdrawal-associated behaviors, such as somatic signs, anxiety-like behavior, and mechanical sensitivity, which are critical components driving the persistence of alcohol dependence and relapse [46]. CBD-treated rats showed reduced alcohol-seeking during extinction, driven by lower initial responding (Fig. 2B, C), likely reflecting a motivational shift that attenuates cue-induced reinstatement [15]. Notably, human studies suggest CBD enhances extinction consolidation, such as in fear conditioning [47], consistent with reduced cue-reactivity. These findings indicate CBD may support behavioral therapies for AUD by weakening alcohol-cue associations, thus lowering relapse risk.

Stress-induced relapse is another major obstacle in AUD treatment [46]. Here, CBD successfully blocked stress-driven reinstatement of alcohol seeking precipitated by the α2-adrenergic receptor antagonist yohimbine [48]. CBD’s anxiolytic properties, partly mediated via serotonergic 5-HT1A receptors [49], likely underlie this capacity to mitigate stress-induced triggers of relapse. Thus, CBD’s behavioral benefits appear multifaceted, addressing both withdrawal and relapse by dampening stress reactivity.

A pivotal finding of this study is that CBD reversed alcohol-induced decreases in neuronal excitability in the BLA. This region is central to alcohol withdrawal and dependence-related behaviors, and its dysregulation contributes to maladaptive processes that drive relapse [43–45]. Previous studies depicted an increase of BLA neuronal excitability during acute alcohol withdrawal or after shorter CIE regimens [50, 51], an effect believed to implicate glutamatergic hyperactivity and plasticity changes resembling long-term potentiation [52]. However, following our protocol of prolonged ethanol exposure (9 weeks of CIE) and a 2-week abstinence, we observed a reduction of neuronal excitability in BLA neurons. This discrepancy may reflect the duration and intensity of alcohol exposure as well as the time point of assessment.

It is possible that prolonged alcohol exposure triggers compensatory or homeostatic plasticity mechanisms to counteract the initial hyperexcitability. Chronic alcohol use can lead to excitotoxicity due to excessive glutamate release, sometimes resulting in neuronal damage and downregulation of excitability over extended periods [53–55]. Moreover, alcohol has been shown to progressively enhance GABAergic inhibition while suppressing glutamatergic transmission in the central amygdala (CeA) [56–58]. Similar time-dependent shifts have been reported in the medial prefrontal cortex (mPFC), where initial withdrawal can surge excitability, followed by diminished activity during protracted abstinence [59, 60]. By compensating for these maladaptive adaptations, CBD-induced restoration of normal BLA excitability may help prevent the affective disturbances as well as the heightened relapse risk associated with chronic alcohol exposure. Similarly, in a model of temporal lobe epilepsy, CBD was found to restore impaired membrane excitability of hippocampal neurons [61], indicating that CBD may have a general capacity to normalize neuronal function in pathological states.

Unlike traditional forced-exposure paradigms, the ethanol vapor self-administration (EVSA) model incorporates volitional elements of alcohol intake, capturing the transition to dependence through active participation [31, 32]. In the EVSA model, CBD administration during the escalation phase not only suppressed the development of alcohol dependence but also prevented neurodegeneration in the nucleus accumbens (NAc) shell and dorsomedial striatum (DMS). In the EVSA model, CBD’s reduction of neurodegeneration markers may be confounded by lower voluntary alcohol intake. While our findings suggest potential neuroprotective effects, future studies with controlled exposure are needed to isolate CBD’s direct effects. These regions are directly implicated in reward and in the shift from goal-directed to habitual drug-seeking behaviors [62, 63]. Chronic alcohol exposure disrupts these processes by eliciting cellular damage and synaptic alterations[64, 65]. Our findings that CBD confers neuroprotection in these areas are consistent with previous work showing its antioxidant and anti-inflammatory properties against alcohol-induced neuronal damage [9, 12, 19, 20]. Although CBD did not prevent neurodegeneration in the NAc core and dorsolateral striatum (DLS), its selective efficacy in the NAc shell and DMS may reflect differential contributions of each subregion to harm avoidance, habit formation, and reward. The NAc shell and DMS are critically involved in early-stage reward processing and goal-directed behaviors, whereas the NAc core and DLS play a more prominent role in habitual responding [62, 63] These results highlight how CBD’s neuroprotective effects may specifically preserve cortical-striatal circuitry related to volitional control, thereby slowing or preventing the transition from voluntary to compulsive alcohol use [32]. Restored BLA excitability and striatal neuroprotection likely converge via BLA-NAc circuits, which are critical in mediating alcohol addiction-like behaviors [43]

CBD’s broad range of targets likely contributes to its beneficial effects. It can act as a negative allosteric modulator of the CB1 receptor under certain conditions [66] and also interacts with 5-HT1A receptors, GPR55, TRPV1 cation channels, μ- and δ-opioid receptors, and peroxisome proliferator-activated receptor gamma (PPARγ) [11, 67–71] These multifaceted mechanisms may help restore homeostatic neuronal activity in the BLA, limit neurodegeneration in the striatum, and reduce withdrawal- and stress-related behaviors. While CBD at 60 mg/kg may have analgesic and anxiolytic effects [72], it lacks sedation (Figs. 1 and 2) and abuse potential [73], supporting its non-psychoactive profile.

The doses used here (30 and 60 mg/kg in rats) parallel other preclinical studies [33–36]. In addition, plasma CBD concentrations following 60 mg/kg subcutaneous administration in rats (~400 ng/mL; Fig. 2B) align with therapeutic levels in human epilepsy trials, where oral doses of 10–20 mg/kg/day achieve steady-state concentrations of ~100–400 ng/mL [74]. These levels support the translational relevance of our findings, as they approximate human doses (~700–1400 mg/day for a 70 kg person) effective for neuropsychiatric conditions. Consistent with prior work, doubling the dose from 30 mg/kg (~180–220 ng/mL) to 60 mg/kg doubled plasma levels, confirming dose-dependent pharmacokinetics [75]. Observational data in humans link CBD to reduced alcohol use [76, 77] and co-administration with alcohol shows no worsened cognitive impairment in healthy volunteers [78–80]. Additionally, CBD may benefit those with alcohol-related sleep disturbances [81] and a recent study further supports CBD’s potential, reducing anxiety and craving in alcoholics [82]. Ongoing trials (NCT05389930, NCT05860699, NCT06512389, NCT05159830, NCT05613608, NCT04873453, NCT03252756) are testing optimal dosing, duration, and sex differences in AUD treatment efficacy.

Our study included both male and female Wistar rats, but exploratory analyses showed no consistent sex differences in CBD’s therapeutic effects. Limited statistical power, due to sample sizes precluded robust sex-specific analyses. Individual data points for males (blue circles) and females (pink circles) are shown in Figs. 1–5. This is particularly relevant given that AUD exhibits distinct sex-specific patterns in humans, and treatment responses may differ between males and females. Future research should incorporate sex as a biological variable to better evaluate CBD’s efficacy across sexes.

In conclusion, chronic CBD administration mitigates key behavioral and neurobiological features of alcohol dependence by reducing withdrawal symptoms, lowering relapse risk, restoring BLA neuronal excitability, and preventing neurodegeneration in striatal regions. Together, these findings highlight CBD’s capacity to preserve functional integrity in neural circuits underlying emotional regulation, reward processing, and habit formation. Further translational research and clinical trials are warranted both to validate CBD’s therapeutic efficacy in human populations and to optimize dosing strategies for individuals with AUD.