Cannabis is also called medical cannabis or medical marijuana if it is used to treat or relieve complaints, symptoms, or diseases, rather than for pleasure. In this sense, any cannabis strain that contains an effective amount of active cannabionoids can be considered medicinal cannabis when used for this purpose.
The history of the use of medical cannabis also has its origins in medicine and pharmacology. This is because humans first started using plants for medicinal purposes instead of food.
Cannabis effects – how does it work in the body?
Although researchers have been studying the effects of cannabis since the 1940s, the effects of cannabinoids have not yet been fully explained. In 1988, the first signs of a specific part of the nervous system were discovered in which the body’s own endocannabinoids act as mediators. However, the main active ingredients of the cannabis plant also bind to receptors in the endocannabinoid system.
So far, scientists have identified two types of receptors that cannabinoids bind to: the CB1 receptor and the CB2 receptor. The first type is most commonly found in the brain, mainly in areas responsible for memory, motivation, emotion, or perception. This is true when using THC. Cannabis use can induce feelings of happiness, calmness, but also impair memory. By blocking CB1 receptors in people taking medications, they can prevent people from feeling good.
On the other hand, the CB2 receptor is found throughout the body. They have a role in regulating the immune system as well as other functions in the liver, muscle, heart, or skin. However, the complex effects of cannabinoids and the effects they cause on the body are still not entirely clear and require further research.
Cannabis medicine – what diseases is it effective for?
A scientific report on cannabis as a medicine, prepared on behalf of TIK, focuses on the current research situation. The diseases and uses listed below – with the exception of schizophrenia – are possible indications for medical marijuana treatment.
Vomiting and nausea often cause stress in cancer patients during chemotherapy. The role of cannabinoids in nausea has been the subject of scientific research since the 1970s, as the mechanisms of action differ from conventional antiemetics, which are drugs that suppress nausea and vomiting. However, there is ambiguity in the review analysis of previous studies: some authors attribute the scientifically proven effect to medical cannabis. However, other scientists cannot recommend cannabinoid therapy. The reason is that there are now safer and more effective antiemetics for nausea and vomiting after chemotherapy.
Medical cannabis appears to outperform placebo therapy for cancer pain. The research done so far against cannabis pain still reveals uncertainties. However, the effect of the medicinal plant on neuropathic pain, the so-called nerve pain, has been scientifically proven.
However, a 2017 review article on pain in multiple sclerosis did not show statistically significant differences when compared to placebo treatment. Likewise, medical marijuana did not have any greater benefit than placebo for acute postoperative pain.
Accordingly, current meta-studies highlight that long-term studies are needed to uncover the efficacy of cannabis as a drug and the ideal dosage for neuropathic pain.
It is also worth mentioning that while some analyzes recommend the use of cannabinoids for pain management and palliative medicine as an individual treatment attempt, patients should nevertheless expect possible side effects. These include confusion, dizziness, or psychosis.
Medical cannabis can also be effective against certain types of epilepsy. Interest in the treatment of epilepsy with medicinal cannabis has grown over the past decade after promising case studies of its effects. The development of a suitable composition for oral administration has been difficult. Interactions with other medications may also occur.
However, more recent results from studies of the effectiveness of cannabinoids in Dravet and Lennox-Gastaut syndromes. In addition, further methodologically qualitative studies of cannabis in focal epilepsy have not yet been completed.
• Depression and anxiety.
The extent to which medicinal cannabis helps relieve depression and anxiety remains unclear. Because the level of research on medical marijuana therapy for depression is still low. Research shows that cannabinoids are superior to placebos, but the few existing studies may be biased.
Research has also shown that pharmaceutical grade tetrahydrocannabinol (TH) with or without cannabidiol (CBD) can help relieve symptoms of secondary anxiety in patients with chronic pain. However, this is a low level of evidence.
Whether medical cannabis can help with attention deficit / hyperactivity disorder (ADHD) has not yet been extensively researched as there are only a few research findings on medical cannabis for ADHD. In this context, experience reports were mainly published. For example, a case study showed that a patient with severe ADHD symptoms (inattention, inappropriate behavior) may behave unnoticed after taking THC.
Additionally, a randomized pilot study of 30 adults with ADHD examined the medicinal effects of Sativex versus placebo. Results for cognitive performance and activity level did not differ significantly between patients. However, symptoms of impulsivity and hyperactivity improved in the Sativex group.
Research to date suggests that more research is needed to demonstrate the potential effects of marijuana on ADHD symptoms in adults. Likewise, future research should focus on knowledge about the endocannabinoid system and ADHD.
• Oncological diseases.
Likewise, the positive effects of medical cannabis on cancer have yet to be determined. However, some studies show the effect of weight gain in cancer patients receiving palliative care as a modest increase in appetite. However, they were not significant compared to placebo.
A new observational study, however, shows that there is insufficient scientific evidence on the use of cannabinoids in cancer patients with loss of appetite. However, previous studies have dealt with short follow-up periods in small groups of patients.
• Sleep disturbances.
The extent to which medicinal cannabis can be used for sleep disorders needs further clarification. Scientific research so far has not specifically addressed medical cannabis for sleep disorders. However, separate studies, such as medical cannabis for pain relief, have documented effects on sleep as a secondary parameter.
However, no evidence has been found to show that medical cannabis has a positive effect on sleep disturbance, so the possible benefits warrant further research.
However, according to recent research, medical cannabis may be effective against schizophrenia. The data collected so far on the efficacy of medical marijuana for schizophrenia seems to be significant, especially with regard to the active ingredient cannabidiol (CBD).
Long-term cannabis use can lead to schizophrenia, but CBD does not appear to have any psychedelic effects. In addition, case studies show that treating acute schizophrenia with CBD has a similar effect to the antipsychotic amisulpride and even causes fewer side effects. However, more large-scale clinical trials of CBD in schizophrenia are needed.
• Other diseases.
Cannabis can still have a positive effect on some types of pain and intestinal diseases. Research on the use of CBD for the treatment of musculoskeletal or tumor pain and rheumatoid arthritis is still rare today. According to this, scientific evidence still needs to be recorded in the context of further research.
Few tests show whether cannabis helps with intestinal diseases. Whether the symptoms of irritable bowel syndrome or Crohn’s disease improve, further research is needed. The same is true for the association with decreased tics intensity in people with Tourette’s and medical cannabis use: whether this really matters has only little evidence from research.
It is also unclear to what extent medicinal cannabis has a positive effect on the disease in glaucoma. However, studies to date have not shown that the use of cannabinoid-containing substances has a different effect on intraocular pressure than placebo.
Medical cannabis is also used for the following diseases and symptoms:
- Borderline syndrome.
- Anorexia and loss of appetite.
- Spasms of the bladder.
- Lyme disease.
- HIV infection.
- Syndrome of post-traumatic stress.
In the case of these diseases, the costs are usually covered by insurance companies. In some cases of illness, health insurance companies allow themselves a detailed examination. If necessary, the costs must be paid by the patient in advance and will be reimbursed after the positive decision of the insurance company.