Small studies have been done, but the results have not been reported or suggest a need for larger studies.
See the General Information section of the health professional version of the Cannabis and Cannabinoids summary for more information on medicinal Cannabis products.
Cannabis and cannabinoids have been studied in the treatment of pain:
Cannabis may be taken by mouth (in baked products or as an herbal tea) or may be inhaled. When taken by mouth, the main psychoactive ingredient in Cannabis (delta-9-THC) is processed by the liver and changed into a different psychoactive chemical (11-OH-THC).
When considering complementary and alternative therapies, patients should ask their health care provider the following questions:
Most of the patients (n = 30) received Cannabis in the form of oral oil drops, with some of the older children inhaling vaporized Cannabis or combining inhalation with oral oils. Structured interviews with the parents, and their child when appropriate, revealed that 40 participants (80%) reported a high level of general satisfaction with the use of Cannabis with infrequent short-term side effects.
In recent decades, the neurobiology of cannabinoids has been analyzed.[13-16] The first cannabinoid receptor, CB1, was identified in the brain in 1988. A second cannabinoid receptor, CB2, was identified in 1993. The highest expression of CB2 receptors is located on B lymphocytes and natural killer cells, suggesting a possible role in immunity. Endogenous cannabinoids (endocannabinoids) have been identified and appear to have a role in pain modulation, control of movement, feeding behavior, mood, bone growth, inflammation, neuroprotection, and memory.
Unlike other commonly used drugs, cannabinoids are stored in adipose tissue and excreted at a low rate (half-life 1–3 days), so even abrupt cessation of cannabinoid intake is not associated with rapid declines in plasma concentrations that would precipitate severe or abrupt withdrawal symptoms or drug cravings.
In a 2016 consecutive case series study, nine patients with varying stages of brain tumors, including six with glioblastoma multiforme, received CBD 200 mg twice daily in addition to surgical excision and chemoradiation.[Level of evidence: 3iiiA] The authors reported that all but one of the cohort remained alive at the time of publication. However, the heterogeneity of the brain tumor patients probably contributed to the findings.
Anorexia, early satiety, weight loss, and cachexia are problems experienced by cancer patients. Such patients are faced not only with the disfigurement associated with wasting but also with an inability to engage in the social interaction of meals.
Salzman C, Kochansky GE, Van Der Kolk BA, Shader RI. The effect of marijuana on small group process. Am J Drug Alcohol Abuse. 1977;4(2):251–5.
Karhson DS, Krasinska KM, Dallaire JA, Libove RA, Phillips JM, Chien AS, et al. Plasma anandamide concentrations are lower in children with autism spectrum disorder. Mol Autism. 2018;9:18.
Schopler E, Reichler RJ, DeVellis RF, Daly K. Toward objective classification of childhood autism: Childhood Autism Rating Scale (CARS). J Autism Dev Disord. 1980;10(1):91–103.
Registered primary efficacy outcome measures were improvement in behavioral problems (differences between whole-plant extract and placebo) on the Home Situation Questionnaire-ASD (HSQ-ASD) and the Clinical Global Impression-Improvement scale with disruptive behavior anchor points (CGI-I). Secondary measures were Social Responsiveness Scale (SRS-2) and Autism Parenting Stress Index (APSI).
For ethical reasons, we used a crossover design in which all participants would receive cannabinoids at least once: after 12-weeks of treatment (‘Period-1’) and a 4-week washout period, participants crossed-over to a predetermined second 12-week treatment (‘Period-2’; Fig. 1). The cross-over design was intended to allow within-participant analyses, comparing the two treatments that each participant received. As we had noted a substantial improvement in our open observational study with whole-plant extract , we ordered treatments a priori to minimize the likelihood of substantial improvement of severe disruptive behaviors in the first period and deterioration in the second period. As we hypothesized that whole-plant extract would be more effective than pure cannabinoids, we excluded the sequence of whole-plant extract followed by placebo.
ASD symptoms (secondary outcome) were assessed with the SRS-2 . Improvement in SRS-2 total score was significantly higher following treatment with whole-plant extract compared with placebo (Table 4). Median total score improved by 3.6 points after placebo (n = 36) versus 14.9 on whole-plant extract (n = 34; p = 0.009) and 8.2 on pure cannabinoids (n = 28; p = 0.80). Results of the second treatment period are presented in Additional file 1: Table S3 and Additional file 1: Figure S3 for transparency.
Consumption of cannabis is reported to enhance interpersonal communication  and decrease hostile feelings . The main components of the cannabis plant (phytocannabinoids) are Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). THC activates the type-1 cannabinoid receptor (CB1R) in the brain; it is psychoactive and can lead to anxiety and psychosis . CBD, on the other hand, is an allosteric modulator of the CB1R and might decrease the effects of CB1R agonists such as THC. It is not psychoactive and has a relatively high toxicity threshold . While THC consumption, especially at a young age, can lead to addiction, cognitive decline, motivational loss, and psychosis, co-consumption of CBD might reduce these risks .