What topics does this cannabis study cover?

This study covers research on: THC, Terpenes, Mental Health.

Where was this research published?

Published in Psychopharmacology on September 25, 2026.

THC Terpenes Mental Health

Rat study finds terpenes can shift THC-related attention impairment

Q: What did this research study find?

In rats, *THC* **dose-dependently reduced accuracy and increased lapses** on a sustained-attention task.

The monoterpenes ⍺-pinene and limonene augment or mitigate THC-induced impairments in sustained attention in rats.

Psychopharmacology • September 25, 2026 • Highly Relevant

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AI Summary

This animal study examined whether the cannabis terpenes α-pinene and limonene change THC-related problems with sustained attention. Twenty-four male and female rats were trained on a rodent psychomotor vigilance task and given oral THC, a terpene, both substances together, or a vehicle control 60 minutes before testing. The researchers measured accuracy and lapses in attention; this was not a human clinical trial.

THC reduced accuracy and increased lapses in a dose-dependent manner. α-pinene at its highest tested dose showed similar tendencies when given alone, while limonene alone did not affect task performance. In combination, the effects were mixed: high-dose α-pinene worsened impairment from a moderate THC dose but reduced some effects of a high THC dose at lower terpene doses. Limonene reduced some impairment from moderate-dose THC, but not from high-dose THC. These findings support the conclusion that cannabis terpenes can modulate THC-related cognitive effects in rats, but the abstract-based results cannot establish that the same interactions occur in humans or provide consumer dosing guidance.

💡 Key Findings

In rats, THC dose-dependently reduced accuracy and increased lapses on a sustained-attention task.

High

80%

α-pinene showed mixed effects: at its highest tested dose it tended to impair performance alone, worsened impairment from moderate-dose THC, but mitigated some effects of high-dose THC at lower doses.

Good

75%

Limonene alone had no effect on task performance, but mitigated impairment from moderate-dose THC and not from high-dose THC.

Good

75%

The findings support the idea that cannabis terpenes can modulate THC-related cognitive effects, although this was an animal study and cannot establish effects in humans.

High

90%

📄 Original Abstract

RATIONALE: α-pinene and limonene are two monoterpenes found in cannabis and cannabis products containing Δ-9-tetrahydrocannabinol (THC). These terpenes are often purported to alter the effects of THC, but empirical data are lacking. OBJECTIVES: The current study sought to determine whether orally administered α-pinene and limonene in combination with THC, would mitigate or augment the adverse effects of THC on performance of a cognitive task of sustained attention in rodents. METHODS: Male and female Sprague-Dawley rats (n = 24, 50% female) were trained in the rodent psychomotor vigilance task (rPVT). Rats received single or combined doses of THC (3 and 10 mg/kg) and one terpene (10-100 mg/kg; limonene or α-pinene) or vehicle (sesame oil) via oral gavage 60-min prior to rPVT test sessions. Data were analyzed with linear mixed models with sex, THC dose, and terpene dose as factors, accepting p < 0.05 as significant. RESULTS: THC dose-dependently reduced accuracy and increased lapses in the rPVT. When administered alone, α-pinene tended to reduce accuracy and increase lapses at the highest dose (100 mg/kg); limonene alone had no effect on rPVT performance at any doses tested. α-pinene (100 mg/kg) exacerbated performance impairments when administered in combination with a moderate dose of THC (3 mg/kg) but mitigated some effects of a high dose THC (10 mg/kg) on rPVT performance (at α-pinene doses 10-30 mg/kg). Limonene (10-100 mg/kg) mitigated performance impairments from 3 mg/kg THC, but not 10 mg/kg THC. CONCLUSIONS: These data lend support to the idea that terpenes found in cannabis can modulate the cognitive effects of the psychoactive constituent THC.

Paper Type

📄 Research

Publication

Journal: Psychopharmacology
Published: September 25, 2026
PMID: 42789049
DOI: 10.1007/s00213-026-07158-w

Authors (5)

Catherine F Moore Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Dr, Baltimore, MD, 21224, USA.
Travis J Wilberger Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Dr, Baltimore, MD, 21224, USA.
Bryan W Jenkins Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Dr, Baltimore, MD, 21224, USA.
Ryan Vandrey Behavioral Pharmacology Research Unit, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Elise M Weerts Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Dr, Baltimore, MD, 21224, USA. eweerts@jhmi.edu.