Cannabinoid Treatment During Late Adolescence Reversed the Cognitive Damage From Early Life Stress in Rats | Research

The takeaway

Rats exposed to early life stress showed impaired memory in adulthood, but two weeks of cannabinoid treatment during late adolescence prevented these cognitive deficits and reduced anxiety in both males and females.

Readers interested in how early life stress affects the brain and whether cannabinoids could help reverse that damage.

Two weeks of adolescent cannabinoid treatment prevented all stress-induced memory impairments

What the researchers found

Researchers tested whether cannabinoid treatment during late adolescence could reverse the long-term cognitive damage caused by early life stress in rats.

Male and female rats were stressed during their first two weeks of life, then treated with the cannabinoid agonist WIN55,212-2 for two weeks during late adolescence. In adulthood, untreated stressed rats showed impaired short-term memory across multiple tasks. Males were additionally impaired in object recognition.

Cannabinoid treatment during adolescence prevented all of these stress-induced memory impairments and reduced anxiety levels. The treatment also normalized stress-induced changes in glucocorticoid receptors and CB1 receptors in the brain, though the specific receptor changes differed between males and females.

Why it matters

Early life stress is a major risk factor for mental health problems. This study suggests the endocannabinoid system may be a target for reversing stress-related cognitive damage, and that there may be a window during late adolescence when intervention is particularly effective.

The numbers in context

Stress during postnatal days 7-14. Cannabinoid treatment during days 45-60 (equivalent to ages 18-25 in humans). Testing at day 90. Both sexes showed impaired spatial and social recognition memory. Males additionally showed impaired object recognition. WIN treatment prevented all impairments.

How the study worked

Male and female rats were exposed to early stress (postnatal days 7-14), injected with WIN55,212-2 (1.2 mg/kg) for two weeks during late adolescence (days 45-60), and tested in adulthood (day 90) for working memory (spatial location, social recognition, novel object recognition), anxiety, and receptor expression in the hippocampus, prefrontal cortex, and amygdala.

What this study cannot tell us

This was an animal study, and the cannabinoid used (WIN55,212-2) is a synthetic full agonist that is much more potent than THC. The stress model (maternal separation) is one of several and may not capture all forms of early adversity. The timing window and dosing may not translate directly to humans.

How to read the evidence

This is an animal study using a synthetic cannabinoid agonist. While the findings are promising, they involve a specific stress model and drug that differ substantially from human experience.

When this study was published

Published in 2016. Research on cannabinoids and stress resilience has continued, though human translation remains limited.

The bigger picture

This research challenges the common narrative that cannabinoid exposure during adolescence is exclusively harmful. In the specific context of early life stress, cannabinoid treatment during a critical developmental window appeared protective rather than damaging, suggesting the effects of cannabinoids depend heavily on context.

Questions still open

Could cannabis use during late adolescence have protective effects in humans who experienced early childhood trauma? Would similar results occur with THC or CBD rather than a full synthetic agonist?

Common questions

Does this mean cannabis is good for teens who experienced trauma?

The study used a potent synthetic cannabinoid in a controlled animal setting, which is very different from human cannabis use. While the findings are intriguing, they cannot be directly applied to human teens using cannabis. The effects of cannabinoids depend heavily on timing, dose, type, and individual circumstances.

Why did males and females show different brain changes?

The sexes had different patterns of receptor changes in response to stress and cannabinoid treatment, suggesting that males and females may use different neurobiological mechanisms to cope with stress. This is consistent with broader research showing sex differences in stress responses and cannabinoid effects.

Read the original research

Cannabinoids reverse the effects of early stress on neurocognitive performance in adulthood.

Learning & memory (Cold Spring Harbor, N.Y.), 23(7), 349-58

View on PubMed ↗Publisher’s paper ↗

Citation

Alteba, Shirley; Korem, Nachshon; Akirav, Irit. (2016). Cannabinoids reverse the effects of early stress on neurocognitive performance in adulthood.. Learning & memory (Cold Spring Harbor, N.Y.), 23(7), 349-58. https://doi.org/10.1101/lm.041608.116