Cannabidiol in the anterior insular cortex attenuates chronic neuropathic pain and comorbid anxiety- and depression-like behaviors: involvement of CB1 and 5-HT1A receptor signaling

Background: Chronic neuropathic pain (NP) is frequently accompanied by anxiety- and depression‑like symptoms, reflecting maladaptive interactions between nociceptive and affective brain networks. The anterior insular cortex (AIC) integrates sensory and emotional dimensions of pain and represents a potential target for pharmacological modulation. Cannabidiol (CBD) exhibits analgesic and anxiolytic/antidepressant‑like properties through interactions with endocannabinoid and serotonergic systems.

Objectives: We investigated whether CBD microinjection into the AIC modulates NP and its affective comorbidities, and whether these effects depend on CB1 and 5‑HT1A receptors.

Methods: Male Wistar rats were subjected to chronic constriction injury (CCI) of the sciatic nerve. Fourteen days later, guide cannulae were implanted into the AIC. On day 21 post‑CCI, animals received intra‑AIC microinjections of CBD (15, 30, or 60 nmol/200 nL) or vehicle. Mechanical (von Frey test) and cold (acetone test) allodynia, anxiety‑like behavior (open field and elevated plus maze tests), and depression‑like behavior (forced swim and sucrose spray tests) were assessed by different psychobiological tests. The role of cannabinoid and serotonergic receptors was addressed by intra‑AIC pretreatment with either the CB1 receptor antagonist AM251 or the 5‑HT1A receptor antagonist WAY-100,635 in independent groups.

Results: AIC pretreatment with CBD dose‑dependently reduced mechanical and cold allodynia and anxiety‑ and depression‑like behaviors, with the most robust effects observed at 60 nmol. AIC Pretreatment with either AM251 or WAY-100,635 abolished the antinociceptive and affective effects of CBD.

Conclusion: CBD administration within the AIC produces integrated analgesic, anxiolytic, and antidepressant-like effects in a model of neuropathic pain. These effects are consistent with the involvement of CB1 and 5-HT1A receptor signaling. The findings identify the AIC as a relevant cortical substrate linking nociceptive and affective processes and support CBD as a promising psychopharmacological strategy for NP associated with emotional comorbidities.”

https://pubmed.ncbi.nlm.nih.gov/42390818

“In conclusion, this study demonstrates that CBD microinjection into the AIC attenuates mechanical and cold allodynia while also reducing anxiety- and depression-like behaviors in an experimental model of NP.”

“Overall, these findings highlight the AIC as a potential neural substrate involved in the interaction between chronic pain and its emotional comorbidities and identify CBD as a promising psychopharmacological approach for NP conditions associated with affective dysfunction.”

https://link.springer.com/article/10.1007/s00213-026-07116-6

Interplay between the HPA axis and inflammation as mechanisms therapeutic targets of Cannabis sativa in depression

“Major Depressive Disorder (MDD) is a highly prevalent and disabling psychiatric disorder, representing a major global health burden across all age groups.

Increasing evidence indicates that its pathophysiology involves a complex interplay between chronic stress, dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, immune activation, and neuroinflammation. Persistent HPA axis hyperactivity, glucocorticoid resistance, and altered expression of key regulators such as FKBP51 contribute to sustained inflammatory signaling and impaired neural plasticity in brain regions involved in mood regulation. Epigenetic mechanisms, including DNA methylation and microRNA-mediated regulation, further modulate stress responsivity, inflammatory pathways, and vulnerability to major depressive disorder.

In this context, growing attention has been directed toward Cannabis sativa and its bioactive constituents as potential therapeutic agents.

Preclinical and clinical evidence suggest that cannabinoids may modulate the endocannabinoid system, attenuate HPA axis hyperactivity, reduce neuroinflammation, and influence monoaminergic and neuroplasticity-related pathways.

This review synthesizes the current literature on the mechanistic links among the HPA axis, inflammation, and MDD, highlighting the emerging role of Cannabis sativa-derived compounds in targeting these interconnected pathways.”

https://pubmed.ncbi.nlm.nih.gov/42239513

https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2026.1801474/full

Therapeutic potential of phytocannabinoids in depression and cognitive dysfunction: Evidence from preclinical models

“Depression is a highly prevalent and incident mental illness. Current pharmacological therapies fail in approximately 30-40% of patients, highlighting the urgent need for novel agents with pleiotropic effects.

This preclinical study aimed to identify new antidepressants and cognitive modulators among five phytocannabinoids: cannabichromene, cannabidiol, cannabidivarin, cannabigerol and cannabinol.

Phytocannabinoids were first evaluated in BV-2 microglial cells for cell viability and then, for anti-inflammatory activity, where BV-2 cells were previously stimulated with lipopolysaccharide (50 ng/mL). Based on these profiles, and comparing with ketamine, cannabidiol, cannabidivarin and cannabigerol were selected to be administered (55 µmol/kg, i.p.) once to healthy CD-1 male mice, and subsequently, administered six times to mice submitted to the unpredictable chronic mild stress (UCMS) protocol, which is a validated model of depression.

Among the phytocannabinoids under investigation, cannabigerol exhibited the lowest cytotoxicity, whereas cannabidiol and cannabidivarin demonstrated the strongest anti-inflammatory effects, significantly reducing nitrite, iNOS and pro-IL1β levels. In healthy mice, only cannabigerol produced consistent antidepressant-like effects in the forced swimming test compared to ketamine. Under UCMS protocol, cannabidivarin was anxiogenic and impaired cognitive and hepatic functions. Cannabidiol, despite its favorable safety profile, failed to ameliorate depressive phenotype or cognitive deficits. Notably, cannabigerol significantly improved cognitive performance, associated with increased dendritic spine density in the hippocampus.

Overall, our unprecedented findings demonstrated that a single administration of cannabigerol ameliorates depressive-like behavior in healthy animals, while multiple administrations improved cognitive function in mice exhibiting depressive-like phenotypes.

Together, these results highlight the therapeutic potential of cannabigerol in mood and cognitive disorders.”

https://pubmed.ncbi.nlm.nih.gov/41934896

“CBG has anxiolytic and antidepressant effects in healthy male CD-1 mice.”

https://www.sciencedirect.com/science/article/pii/S0753332226003318?via%3Dihub


Bridging reward and resilience: the endocannabinoid system as a unifying mechanism in exercise-induced protection against major depressive disorder

“Major depressive disorder (MDD) refers to a complex mental disorder defined by hindered reward system and hindered stress resilience. The limitations of traditional monoamine antidepressants have prompted the academic community to study new pathological processes and intervention strategies. Major depressive disorder arises from a complex interplay of psychological, social, and biological factors.

Among the latter, dysfunction of the endocannabinoid system (ECS) has emerged as a critical pathological mechanism contributing to the core symptoms.

This review demonstrates the key idea that exercise as a powerful non-pharmacological intervention can increase stress resilience and exert antidepressant effects by positively activating the ECS.

Exercise, especially moderate intensity aerobic exercise, can significantly increase the levels of major endogenous cannabinoids AEA and 2-AG, and exert effects at multiple levels by activating CB1 receptors: at the acute level, it can immediately promote mood, generate analgesic effects and improve the termination of the stress response; At the long-term level, it can drive synaptic plasticity, facilitate hippocampal neurogenesis, and regulate neuroimmunity, thereby obtaining lasting structural improvement of emotional and stress neural circuits.

These processes work together to reshape the brain’s reward function and establish internal resilience against stress. In comparison to drug therapy, ECS-regulated exercise interventions have the unique benefits of high safety, systemic advantages, and endogenous reward reinforcement.

Thus, individualized exercise therapy for ECS represents a promising mechanism-induced non-pharmacological intervention approach offering a new aspect and perspective for the prevention and rehabilitation of depression.”

https://pubmed.ncbi.nlm.nih.gov/41877874

https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2026.1766980/full

“Exercise activates the endocannabinoid system”

https://pubmed.ncbi.nlm.nih.gov/14625449

UK medical Cannabis registry: A two-year case series of clinical outcomes in depression

Background: Whilst preclinical evidence details the effects of cannabinoids on mood regulation, there is a paucity of clinical evidence on the use of cannabis-based medicinal products (CBMPs) in individuals with depression. This study aims to evaluate longitudinal changes in patient-reported outcome measures (PROMs) and the incidence of adverse events over 24 months in patients treated with CBMPs for depression.

Methods: Patient data from the UK Medical Cannabis Registry were used for analysis. PROMs, including the Patient Health Questionnaire-9 (PHQ-9), Generalised Anxiety Disorder-7 (GAD-7), Single-Item Sleep Quality Scale (SQS), EuroQol 5-Dimension 5-Level (EQ-5D-5L), and Patient Global Impression of Change (PGIC), were measured at baseline, 1, 3, 6, 12, 18, and 24 months. Adverse events (AEs) were also recorded. P < 0.050 was considered statistically significant.

Results: Of the 34,563 patients in the UK Medical Cannabis Registry on January 6th 2025, 698 (2.02 %) patients were included in the analysis. Improvements were observed across the PHQ-9. GAD-7, SQS, and EQ-5D-5L index value at all time points compared to baseline (p < 0.001). At baseline, half of the patients reported severe anxiety (GAD-7 ≥ 15: 50.86 %, n = 355), which was correlated with depression severity (PHQ-9; r = 0.67, p < 0.001). Sixty-three patients (9.03 %) reported at least one AE during treatment, of which 85 % (n = 411) were mild or moderate.

Discussion: Initiation of CBMPs was associated with statistically and clinically significant improvements in depression, anxiety, sleep quality, and health-related quality of life among patients. Improvements were most prominent in the first 3 months. Limitations of the study mean that no causal relationship can be ascertained.

Conclusion: The positive findings from this and other observational data support future evaluation of CBMPs for the treatment of depression to establish their efficacy.”

https://pubmed.ncbi.nlm.nih.gov/41506388

“This UK Medical Cannabis Registry study of patients with treatment-resistant depression prescribed CBMPs demonstrated sustained and clinically meaningful improvements in depression, anxiety, health-related quality of life, and sleep quality over 24 months. Improvements were most pronounced within the first three months and were sustained thereafter. Adverse events were infrequent and predominantly mild to moderate.”

https://www.sciencedirect.com/science/article/pii/S0165032725025728?via%3Dihub

Cannabidiol Alleviates LPS-Induced Depressive-Like Behaviors Via Improving Mitochondria Function

“Mitochondrial autophagy has been regarded as a new signaling pathway for the action of antidepressant drugs.

The neuroprotective properties of the non-psychoactive cannabinoid cannabidiol (CBD) have been demonstrated in different animal models of neurological disorders. However, the therapeutic effect of cannabidiol on neuroinflammation-induced depression and its underlying molecular mechanisms involved has not been comprehensively studied.

In this study, depressive-like behaviors were induced in male C57BL/6 mice by LPS injection, with intragastric administration of CBD (70 or 140 mg/kg/day) for 6 days.

Our results demonstrated that CBD treatment significantly attenuated lipopolysaccharide (LPS)-induced depressive-like behaviors, accompanied by a marked amelioration of synaptic healthiness in the hippocampal region.

CBD effectively inhibited reactive oxygen species production, normalized the levels of oxidative stress markers, and restored superoxide dismutase activity, involving a mechanism that promotes mitochondrial biogenesis and mitophagy. In addition, LPS-induced neuroinflammation was reduced by CBD, as evidenced by a marked decrease in neuroinflammatory activation markers. CBD also inhibited LPS-activated inflammasome activation by targeting NLRP3/IL-1β/Caspase-1 signaling pathway.

These findings suggest that CBD may be a potential therapeutic drug for managing major depressive disorder.”

https://pubmed.ncbi.nlm.nih.gov/41484536

https://link.springer.com/article/10.1007/s12035-025-05614-w

Neuropathic Pain and Related Depression in Mice: The Effect of a Terpene and a Minor Cannabinoid in Combination

Background/Objectives: Neuropathic pain is one of the most severe types of chronic pain. Although it is difficult to manage, it often co-occurs with depression. Yet, no medication addresses the neuropathic pain and depression comorbidity. Therefore, developing integrated treatment strategies that address both pain and depression is a major public health priority and an unmet need affecting millions. 

Methods: In this study, we investigated the effect of combining a terpene, Beta-Caryophyllene (BCP), and cannabidiol (CBD) on neuropathic pain and associated depression. We employed a chronic constriction injury (CCI) neuropathic pain model and a series of behavioral tests to evaluate how oral administration of this combination influences neuropathic pain and depression-like behaviors in mice. We employed immunohistochemistry and proteomics approaches to explore the mechanism. 

Results: The analgesic effect of combining CBD and BCP is synergistic in neuropathic pain and also shows an antidepressant effect. Additionally, we found that this combination decreases neuroinflammation associated with CCI and affects specific genes involved in the inflammation. 

Conclusions: This work provides preclinical scientific evidence supporting the potential usefulness of this combination for neuropathic pain and associated depression.”

https://pubmed.ncbi.nlm.nih.gov/41463111

“Cannabis plants contain various non-psychoactive compounds, including Caryophyllene (BCP). BCP is a natural bicyclic sesquiterpene that acts as a natural ligand for the cannabinoid type 2 receptor (CB2) and is an FDA-approved food additive. It has several benefits, such as pain relief, antidepressant effects, and anti-inflammatory properties.

Given this background, the main goal of this study is to test the hypothesis that combining CBD and BCP is effective for neuropathic pain while also demonstrating antidepressant effects.”

“In conclusion, the proposed project introduces the concept that the combination of CBD and BCP can effectively relieve neuropathic pain while also addressing depression. This knowledge will advance the field by providing preclinical scientific evidence supporting the potential usefulness of this combination for neuropathic pain and associated depression.”

https://www.mdpi.com/2227-9059/13/12/3103


Medicinal use of non-prescribed cannabis: a cross-sectional survey on patterns of use, motives for use, and treatment access in the Netherlands

Background: Despite the Netherlands having one of the world’s oldest medical cannabis programs, the majority of people who use cannabis for medicinal purposes continue to rely on non-prescribed sources. This study investigates patterns of use, motives for use, perceived effectiveness, and barriers to accessing prescribed cannabis among individuals self-medicating with non-prescribed cannabis.

Methods: A cross-sectional online survey was conducted between January and April 2023, using convenience sampling primarily via social media. Participants (N = 1059) were adults (18 years or older) residing in the Netherlands who self-reported current use of non-prescribed cannabis-based products to manage physical or mental health symptoms.

Results: Cannabis was used to manage a wide range of conditions, most commonly chronic pain, sleep disorders, depression, and ADHD/ADD, with three out of four participants reporting use for multiple conditions. Most participants obtained cannabis from coffeeshops, although one in four also reported home cultivation as a source. Participants typically smoked cannabis with tobacco, reported (near-)daily use for therapeutic purposes, and indicated a monthly expenditure of €100. The majority was not aware of the THC and CBD content of their products. Perceived effectiveness was rated as high, and more than half of those with a history of prescription medication use reported substituting cannabis for these medications. Only a minority of participants had ever used, or were currently using, prescribed cannabis. Commonly cited barriers included perceived lower quality, higher cost, and lower ease of access compared with non-prescribed cannabis.

Conclusions: The widespread use of non-prescribed cannabis for medicinal purposes in the Netherlands reflects both unmet health needs and barriers within the regulated medical cannabis system. Risky use practices – such as smoking cannabis with tobacco and using products without knowing their cannabinoid content – raise public health concerns. The findings highlight the need for harm reduction strategies and policies that better align medical cannabis regulation with patients’ real-world behaviours and care needs.”

https://pubmed.ncbi.nlm.nih.gov/41331499

https://link.springer.com/article/10.1186/s42238-025-00355-y

The Endocannabinoid System: Pharmacological Targets and Therapeutic Potential in CNS Disorders

“The endocannabinoid system (ECS) influences a wide range of brain functions, including synaptic transmission, neuroplasticity, emotion, and immune regulation within the central nervous system, with CB1 and CB2 receptors mediating various neurophysiological and pathophysiological outcomes. Thus, growing interest in its therapeutic potential has prompted extensive research into how cannabinoid receptors contribute to the pathophysiology of neurological and psychiatric disorders, particularly CB1 and CB2.

This review has integrated findings from studies published between 2015 and 2025, covering conditions, like depression, anxiety, pain, multiple sclerosis, and Parkinson’s disease. We have also examined recent advances in receptor pharmacology and experimental technologies, including cryo-EM, optogenetics, and chemogenetics.

Although ECS-targeted therapeutics hold considerable promise, some key challenges remain in establishing safe and effective dosing protocols and integrating these approaches into clinical frameworks.

This review has provided an updated perspective on the system’s role in brain health and its potential to inform future therapeutic directions. Thus, ECS-targeted strategies may become increasingly important in managing and treating central nervous system disorders.”

https://pubmed.ncbi.nlm.nih.gov/41178765/

https://www.eurekaselect.com/article/151549

Measuring the Effects of Cannabis on Anxiety and Depression Among Cancer Patients

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“Introduction: Cancer patients are increasingly turning to cannabis products to modulate physical and psychological symptoms despite limited evidence supporting their efficacy. We aimed to explore cancer patients’ self-reported anxiety and depression symptoms in response to cannabis use.

Methods: This longitudinal study examined how patient-reported anxiety and depression symptoms varied according to the dose, ratio of tetrahydrocannabinol (THC) to cannabidiol (CBD), and route of administration of cannabis products among cancer patients. Change in self-reported anxiety and depression symptoms was evaluated in 1962 cancer patients after 30 days of enrollment in the Minnesota Medical Cannabis Program.

Results: Anxiety scores improved more in patients taking higher doses of CBD (> 14.3 mg/day) compared to those taking lower doses (< 4.6 mg/day) and among patients using enteral cannabis products. Depression scores also improved more for patients taking enteral products.

Discussion: Anxiety scores varied according to the dose of cannabis, the ratio of THC to CBD, and the route of administration of cannabis products. In contrast, depression scores only varied according to the route of administration.

Conclusions: This study of cancer patients in Minnesota suggests that patterns of cannabis use that include relatively higher doses of CBD taken enterally may improve the quality of life of cancer survivors who report anxiety and depression. This study constructs a foundation for future research to improve the tailoring of cannabis-related educational materials to patients’ needs and inform the training of healthcare professionals on how to recommend cannabis products for cancer survivors.”

https://pubmed.ncbi.nlm.nih.gov/41163433/

“Given the high prevalence of anxiety and depression symptoms among cancer patients, along with the potential for cannabis products to alleviate these serious psychological symptoms, this study suggests specific patterns of use that may improve the quality of life of cancer survivors.”

https://onlinelibrary.wiley.com/doi/10.1002/cam4.71342