CBD

Authors:

Adriana Yndart Arias

Findings:

Cannabidiol is presented as an emerging strategy for treating cognitive impairments, based on a review of randomized trials.

Study Quality Assessment:

Review of randomized trials.

Authors:

Arjun Narala, Chandrashekhar Kocherlakota, Kumar SD Kothapalli, Nagaraju Banda, Prasad Rao Gundugurti, Ramyasree Thatikonda, Siva Sankara Rao Yadlapalli

Findings:

Nanodispersible CBD significantly improved primary (GAD-7, HAM-A scores) and secondary outcomes (CGI-I, CGI-S, PHQ-9, PSQI scores) compared to placebo in treating mild to moderate anxiety disorders. The treatment was found to be therapeutically safe, well-tolerated, with no serious adverse events, and also effective for associated depression and sleep quality disturbances.

Participants:

N=178 participants with mild to moderate anxiety

Dosage:

Nanodispersible cannabidiol oral solution (150 mg/mL)

Study Quality Assessment:

Phase 3 prospective, randomized, double blind, parallel group, placebo-controlled, 15-week cohort study conducted at multiple sites. N=178. Conflict of interest declared for several authors affiliated with pharmaceutical companies.

All Effects:

Authors:

Black et al.

Findings:

This review summarizes evidence on cannabinoid effects for major depression, bipolar disorder, anxiety, PTSD, and schizophrenia, suggesting therapeutic potential due to the endocannabinoid system's role in these conditions. However, the text concludes that current evidence supporting cannabinoid use for mental disorders is unconvincing due to study limitations (small samples, short duration, lack of follow-up), mixed results across studies, and potential harms associated with regular/heavy cannabis use. High-quality clinical trials are deemed necessary to confirm efficacy and safety.

Participants:

The text reviews studies involving various participants, including: medication-free women with major depression, patients treated with electroconvulsive therapy, suicide victims with/without psychiatric history, female patients with high comorbid anxiety, adults exposed to childhood trauma, psychiatric patients, general population members, bipolar patients (including type I), healthy adults/volunteers, patients with social anxiety disorder (SAD), drug-naive subjects with SAD, patients with generalized anxiety disorder, panic disorder, or agoraphobia, individuals with PTSD, psychiatric outpatients with PTSD, schizophrenic patients (including first-episode, treatment-refractory, stable outpatients), and individuals vulnerable to psychosis. Several ongoing clinical trials mentioned target specific groups like those with bipolar depression, various anxiety disorders, PTSD, or schizophrenia.

Dosage:

Specific dosages mentioned in reviewed studies or ongoing trials include: Bipolar: CBD (600-1200 mg/day oral; 150-300 mg/day for 12 weeks; 600 mg one-time oral), THC (2mg & 4mg vaporized), Dronabinol (5 mg one-time oral). Anxiety: CBD (400 mg single dose; 600 mg acute dose; 30 mg/day sublingual tincture for 4 weeks; 200-800 mg/day capsules for 8 weeks; 150-300 mg/day oil; up to 100 mg/day soft gels for 12 weeks), THC (7.5 mg oral - anxiolytic; 12.5 mg oral - increased negative mood). PTSD: THC (5 mg sublingual twice daily for 3 weeks), Dronabinol (5 mg & 10 mg), CBD (300 mg fixed dose oil). Schizophrenia: Dronabinol (2.5, 5, 10 mg increasing doses for 3 weeks), CBD (1000 mg adjunct for 6 weeks; 600 mg/daily adjunct for 6 weeks). Nabilone use mentioned for PTSD nightmares. Dose-dependent effects noted for THC in anxiety (low dose anxiolytic, high dose anxiogenic) and psychosis.

Study Quality Assessment:

The text describes itself as a review summarizing evidence. It mentions findings from various study types including: systematic reviews, meta-analyses, randomized controlled trials (RCTs, some double-blind, placebo-controlled), cross-sectional investigations, large-scale epidemiological studies, independent cohort studies, population-based longitudinal studies, open-label studies, case reports/series, controlled cohort studies, postmortem studies, genetic studies, and neuroimaging studies (SPECT, PET). Limitations acknowledged include: equivocal evidence for cannabis-based interventions, weak evidence for efficacy/safety in major depression, conflicting results potentially due to varying doses, THC/CBD content, and administration modes, limited and insufficient evidence for PTSD improvement, potential confounding by sample size/methodology differences in schizophrenia studies, and general limitations of existing clinical studies (small patient numbers, short duration, lack of reliable follow-up). Funding source acknowledged (University of Cagliari), and authors declared no conflict of interest.

All Effects:

Findings:

This review summarizes evidence for cannabinoid (natural/synthetic, THC/CBD) use in major depression, bipolar disorder, anxiety, PTSD, and schizophrenia, noting dysregulation of the endocannabinoid system in these conditions. While some studies and anecdotal reports suggest potential benefits (e.g., CBD for anxiety/psychosis; THC for PTSD nightmares), the overall evidence for therapeutic efficacy is considered unconvincing, weak, mixed, or equivocal. Risks associated with heavy/regular cannabis use (worsening symptoms, psychosis risk) are highlighted, and the need for more high-quality, large-scale clinical trials to confirm efficacy and safety is emphasized.

Participants:

The text reviews studies involving various participants including: patients with mental disorders (major depression, bipolar disorder, anxiety disorders, PTSD, schizophrenia), medication-free women with major depression, suicide victims, drug-naive subjects with social anxiety disorder, healthy adults/volunteers, psychiatric outpatients, and individuals exposed to childhood trauma or the World Trade Center attacks. Specific patient characteristics (e.g., treatment-refractory, first-episode psychosis) are sometimes mentioned.

Dosage:

Specific dosages mentioned include: CBD (single 400mg or 600mg; 600-1200mg/day; 30mg/day; 150-300mg/day; 200-800mg/day; up to 100mg/day; 1000mg/day; 600mg/day; fixed 300mg), THC (vaporizer 2mg & 4mg; oral 7.5mg & 12.5mg; sublingual 5mg twice daily), Dronabinol (synthetic THC) (oral 5mg; 2.5, 5, 10mg daily; 5mg & 10mg). Administration methods mentioned include oral, sublingual, vaporizer, smoked flower, ingested edible, oil capsules, tincture, soft gel capsules. Dose-dependent effects (e.g., low-dose THC anxiolytic, high-dose anxiogenic) and influence of CBD:THC ratio are noted.

Study Quality Assessment:

The text cites various study types: systematic reviews, meta-analyses, randomized controlled trials (RCTs, including double-blind, placebo-controlled, multicenter), cross-sectional studies, epidemiological studies, cohort studies, longitudinal studies, open-label studies, case reports/series, observational studies, postmortem studies, genetic studies, and neuroimaging studies (SPECT, PET, fMRI). It notes limitations such as preliminary results, equivocal/weak/mixed/conflicting evidence, small sample sizes, short duration of therapy, lack of reliable follow-up, potential confounding factors, and differences in methodology (doses, THC/CBD content, administration modes). Several ongoing/registered clinical trials (referenced by ClinicalTrials.gov identifiers) are mentioned.

All Effects: