Female Rats Work Harder for THC Vapor, and Prior Exposure Increases Use

Among 96 rats, both males and females voluntarily self-administered THC vapor over several months. Female rats responded more than males as the effort required increased. Prior THC vapor exposure significantly increased later self-administration, suggesting sensitization. Rats titrated their intake based on THC concentration.

Controlled animal study with 96 Sprague Dawley rats (male and female) pre-exposed to THC or vehicle vapor, then trained to self-administer THC vapor under increasing effort requirements and varying concentrations.

This model closely mirrors human cannabis inhalation behavior and reveals important sex differences and sensitization effects that could inform understanding of why some people develop cannabis use disorder.

The sex differences found here parallel human data showing women may progress to cannabis use disorder faster. The pre-exposure sensitization effect has implications for understanding how early cannabis use might facilitate later problematic use.

Animal models cannot fully replicate human cannabis use behavior. Propylene glycol vehicle may have its own effects. Limited to one strain of rats. Short pre-exposure period may not reflect human use patterns.