What topics does this cannabis study cover?

This study covers research on: CBD, Anxiety, Pain, Neuroprotection, Mental Health.

Where was this research published?

Published in Behavioural brain research on January 5, 2026.

CBD Anxiety Pain Neuroprotection Mental Health

CBD reduces pain and anxiety differently based on individual traits

Q: What did this research study find?

**CBD at 5 mg/kg daily reduced pain sensitivity across all rat lineages**, though the effect was less pronounced in anxiety-prone rats, suggesting individual differences in treatment response.

Chronic cannabidiol treatment effects on contextual fear and neuropathic pain in Carioca rats high and low conditioned freezing.

Behavioural brain research • January 5, 2026 • Highly Relevant

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AI Summary

This study examined whether chronic cannabidiol (CBD) treatment could reduce both pain and anxiety in rats, using a specially bred animal model designed to study generalized anxiety disorder (GAD). Researchers used three distinct rat lineages—those with high anxiety responses, low anxiety responses, and a control group—and gave them either nerve damage surgery or sham surgery. CBD at 5 mg/kg daily reduced pain sensitivity across all rat types, though the effect was somewhat weaker in the anxiety-prone rats. The treatment also showed anxiolytic (anxiety-reducing) effects in some groups, particularly in control and high-anxiety rats undergoing pain surgery.

The research revealed important insights about how CBD's effectiveness varies depending on individual anxiety traits. CBD reduced anxiety-related freezing behavior in all sham-surgery groups but failed to help high-anxiety rats with actual nerve damage, suggesting that baseline anxiety levels and concurrent pain may influence treatment response. The study also found that CBD affected brain chemistry differently across the rat lineages, with the compound restoring BDNF (brain-derived neurotrophic factor) levels in the hippocampus—a brain region crucial for learning and memory—only in control rats. This points to how CBD may work through different neurobiological pathways depending on individual traits.

These preclinical findings have significant implications for treating patients with co-occurring anxiety and chronic pain. The differential effects across anxiety-prone and anxiety-resistant groups suggest that CBD treatment outcomes may vary based on individual psychological profiles, highlighting the importance of personalized medicine approaches. Future clinical trials should consider whether patients' baseline anxiety levels predict CBD effectiveness, potentially leading to better treatment strategies for the millions experiencing both GAD and chronic pain.

💡 Key Findings

CBD at 5 mg/kg daily reduced pain sensitivity across all rat lineages, though the effect was less pronounced in anxiety-prone rats, suggesting individual differences in treatment response.

High

85%

CBD showed anxiolytic effects in some but not all groups—reducing anxiety-related freezing in control and anxiety-resistant rats under pain conditions, but failing to reduce freezing in anxiety-prone rats with nerve damage.

High

80%

CBD restored BDNF levels in the dorsal hippocampus only in control rats, indicating that the compound's effects on brain plasticity and neurotropic factors vary based on individual anxiety traits.

Good

75%

The combination of pain and high anxiety may create a treatment-resistant state, as CBD's anxiolytic benefits disappeared in high-anxiety rats with actual nerve injury, despite helping other groups.

Good

78%

📄 Original Abstract

Generalized anxiety disorder (GAD) and chronic pain often co-occur, and cannabidiol (CBD) has a promising treatment for both conditions. In this study, we evaluated whether chronic systemic treatment with CBD decreases pain sensitivity and anxiety-like behavior in a validated animal model of GAD - the Carioca rat lineages, selectively bred based on extreme responses to contextual fear conditioning: high freezing (CHF), low freezing (CLF), and a non-selected control group (CTL). Male rats from each lineage (n = 32 per group) were submitted to a chronic constriction injury of the sciatic nerve (CCI) or SHAM surgery. Sensory responses were assessed with the von Frey (mechanical sensitivity) and acetone (thermal sensitivity to cold) tests before CCI and on postoperative days 13 and 23. CBD (5 mg/kg, i.p., daily) was administered from day 14-23. Locomotor and anxiety-like behaviors were evaluated using the open field test (OFT) on day 22, and contextual fear conditioning (CFC) was reassessed on day 24. CBD treatment reduced allodynia across all lineages, although this effect was less in CHF rats. In the OFT, CBD exerted an anxiolytic effect in CTL and CHF rats under CCI, and increased locomotion was observed in CLF+SHAM rats. In the CFC, CBD reduced freezing in all SHAM-treated lineages but not in CHF rats with CCI. BDNF expression in the dorsal hippocampus varied by lineages, with CBD restoring BDNF levels in CTL rats. These findings suggest that CBD has differential analgesic and anxiolytic effects across anxiety-prone and anxiety-resistant rat breeding lineages and may modulate hippocampal plasticity through BDNF. Additionally, these preclinical results can improve future strategies for managing patients with GAD and chronic pain.

Paper Type

📄 Research

Publication

Journal: Behavioural brain research
Published: January 5, 2026
PMID: 41027533
DOI: 10.1016/j.bbr.2025.115855

Authors (10)

Carolina Macêdo-Souza Department of Psychology, Faculty of Philosophy, Science and Letters of Ribeirão Preto, University of São Paulo, Brazil; National Institute for Translational Medicine (INCT-TM; CNPq), São Paulo, Brazil.
Aline A Ferrarese-Tiballi Department of Psychology, Faculty of Philosophy, Science and Letters of Ribeirão Preto, University of São Paulo, Brazil.
Silvia Soares Maisonnette Department of Psychology, Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro, Brazil.
Flávia Rosseti Department of Psychology, Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro, Brazil.
Carlos Henrique Rocha Catalão Department of Psychology, Faculty of Philosophy, Science and Letters of Ribeirão Preto, University of São Paulo, Brazil.
+5 more authors