Repeated footshock stress during cocaine self-administration escalated intake equally in male and female rats, with CB1 receptor antagonism reducing cocaine intake in both sexes but with different sensitivity patterns.
Read this if you are interested in how stress drives drug use and the role of the endocannabinoid system in addiction.
Both sexes escalateStress-induced cocaine escalation occurred equally in males and females, mediated by CB1 receptors
What the researchers found
Daily footshock stress produced escalation of cocaine self-administration similarly in both sexes. Female stress-escalated rats showed greater timeout responding and "front-loading" behavior. The CB1 antagonist rimonabant reduced cocaine intake in stressed males specifically (not unstressed controls), while in females it reduced intake across conditions but with greater sensitivity in stressed rats. This suggests stress recruits CB1 signaling to regulate cocaine-taking behavior in both sexes.
Why it matters
Stress is a major driver of drug use escalation, and understanding the biological mechanisms — particularly sex differences — is essential for developing targeted interventions. This study shows the endocannabinoid system is a key mediator.
The numbers in context
- Equal cocaine escalation in both sexes under stress
- Rimonabant in males: only reduced intake in stress+cocaine group
- Rimonabant in females: reduced intake across groups
- Female stressed rats: both doses (1, 3 mg/kg) effective
- Cocaine dose: 0.5 mg/kg/infusion IV
- 2-hour access in 4x30-min blocks
How the study worked
Male and female Sprague-Dawley rats self-administered cocaine during modified short-access paradigm with daily footshock stress. Systemic rimonabant (CB1 inverse agonist/antagonist) tested at 1 and 3 mg/kg. Behavioral measures included intake, timeout responding, and front-loading.
Who was studied
Male and female Sprague-Dawley rats self-administering cocaine with and without daily stress
What this study cannot tell us
Preprint not yet peer-reviewed. Rat stress model may not capture human stress-drug interactions. Rimonabant has been withdrawn from human use due to psychiatric side effects. Only one cocaine dose tested.
How to read the evidence
Preprint animal study (not yet peer-reviewed) with sex comparison and pharmacological intervention. Strong preclinical design.
When this study was published
Published as preprint in 2023. Extends previous male-only findings to include females.
The bigger picture
The convergence of stress, endocannabinoid, and reward circuits in driving drug use has major implications for treatment. While rimonabant itself is not viable due to side effects, understanding that CB1 mediates stress-driven cocaine escalation points toward safer endocannabinoid-targeting strategies.
Questions still open
- Could peripherally-restricted CB1 antagonists reduce stress-driven cocaine use without psychiatric side effects?
- Do sex differences in CB1 sensitivity translate to humans?
- Would FAAH or MAGL inhibitors have the opposite effect, increasing cocaine escalation?
Read the original research
Repeated footshock stress induces an escalation of cocaine self-administration in male and female rats: Role of the cannabinoid receptor 1.
bioRxiv : the preprint server for biology
Citation
Gaulden, Andrew D; Tepe, Erin A; Sia, Eleni; Rollins, Sierra S; McReynolds, Jayme R. (2023). Repeated footshock stress induces an escalation of cocaine self-administration in male and female rats: Role of the cannabinoid receptor 1.. bioRxiv : the preprint server for biology. https://doi.org/10.1101/2023.02.23.529774