Male and Female Rats Showed Similar THC Withdrawal, with One Exception | Research

The takeaway

When THC-dependent rats were given a withdrawal-precipitating drug, males and females showed broadly similar withdrawal signs, though females exhibited more retropulsion.

Read this if you want to understand how cannabis withdrawal compares between males and females.

First study of THC dependence in adult rats of both sexes

What the researchers found

After 6.5 days of twice-daily THC administration (30 mg/kg), rats challenged with the CB1 antagonist rimonabant displayed a pronounced withdrawal syndrome spanning multiple domains. Somatic signs included paw tremors, head twitches, and retropulsion. Cognitive disruptions included lack of locomotor habituation and impaired prepulse inhibition. Affective changes included increased startle reactivity.

With the exception of increased retropulsion (backward walking) in female rats, sex differences were minimal. Both sexes showed comparable withdrawal severity across most measures.

During chronic THC dosing, both male and female rats experienced weight loss, and females showed disrupted estrous cycling. Spontaneous withdrawal (without rimonabant) produced only minimal overt signs, consistent with the pattern seen in human cannabis withdrawal.

Why it matters

This was the first study to systematically examine THC dependence in both male and female adult rats. The finding that withdrawal extends beyond somatic signs into cognitive and affective domains mirrors what humans report and suggests animal models may be more useful for studying cannabis withdrawal than previously thought.

The numbers in context

THC dose: 30 mg/kg twice daily for 6.5 days. Withdrawal was precipitated with rimonabant. Female rats showed more retropulsion than males. Both sexes showed disrupted prepulse inhibition and increased startle reactivity.

How the study worked

Adult male and female Sprague-Dawley rats received either 30 mg/kg THC or vehicle twice daily for 6.5 days. On day 7, rats were challenged with either vehicle or the CB1 antagonist rimonabant to precipitate withdrawal. Researchers assessed somatic signs (paw tremors, head twitches, retropulsion), cognitive measures (locomotor habituation, prepulse inhibition), and affective measures (startle reactivity).

What this study cannot tell us

This was an animal study, and rat withdrawal patterns may not fully translate to human experience. Withdrawal was precipitated by a CB1 antagonist rather than occurring spontaneously, which may produce a more intense and acute withdrawal profile than natural cessation. The THC doses used were high relative to typical human consumption.

How to read the evidence

This is an animal study providing preliminary evidence. Findings need human confirmation.

When this study was published

Published in 2014. Research on sex differences in cannabis effects and withdrawal has expanded substantially since.

The bigger picture

While female rodents show enhanced sensitivity to acute THC effects, this study found that chronic THC exposure produces largely similar withdrawal profiles across sexes. The breadth of withdrawal signs observed, spanning somatic, cognitive, and affective domains, parallels the multi-dimensional withdrawal syndrome described in human cannabis users.

Questions still open

Do the cognitive and affective components of withdrawal drive relapse more than somatic symptoms? Would sex differences become more pronounced with different THC doses or longer exposure periods? How do hormonal fluctuations interact with cannabinoid withdrawal?

Common questions

What is precipitated withdrawal?

Instead of waiting for THC to naturally leave the body, researchers administered rimonabant, a drug that blocks CB1 receptors and instantly removes cannabinoid signaling. This produces a rapid, measurable withdrawal syndrome useful for research, but more intense than natural withdrawal.

Why do sex differences in drug response matter?

Women and men can respond differently to the same drug in terms of effects, side effects, dependence development, and withdrawal. Understanding these differences helps develop more personalized treatment approaches.

Read the original research

Evaluation of sex differences in cannabinoid dependence.

Drug and alcohol dependence, 137, 20-8

View on PubMed ↗Publisher’s paper ↗

Citation

Marusich, Julie A; Lefever, Timothy W; Antonazzo, Kateland R; Craft, Rebecca M; Wiley, Jenny L. (2014). Evaluation of sex differences in cannabinoid dependence.. Drug and alcohol dependence, 137, 20-8. https://doi.org/10.1016/j.drugalcdep.2014.01.019