Results from clinical research demonstrate that cannabis can offer a safe and effective treatment for the following illnesses: muscle spasms in multiple sclerosis, Tourette syndrome, chronic pain, nausea and vomiting in HIV/AIDS and cancer chemotherapy, loss of appetite from cancer, hyperactivity of the bladder in patients with multiple sclerosis and spinal cord injury, and dyskinesia caused by levodopa in Parkinson's disease.
According to a research done by Roger Anderson and colleagues of Anderson Clinical Research in Pittsburgh, 85% (23/27) of HIV/ AIDS patients who added THC, to their current antiretroviral therapy had a 50% improvement in symptoms of nausea and vomiting. Patients were assessed by questionnaire for the number of minutes they did not feel well in the previous 48 hours, the number of episodes of vomiting, and the severity of nausea during that same period. 93% of patients in the group taking THC twice a day had a greater than 50% improvement in symptoms of nausea and vomiting, and 77% of patients taking THC at bedtime had a greater than 50% improvement.
Patients with glaucoma and are resistant to conventional therapies, THC decreased the intraocular pressure by between 20 and 30% (Porcella et al. 2001). The data confirmed that CB1 receptors that have been found in the ciliary body of the eye have direct involvement in the regulation of human intraocular pressure. THC binds to the CB1 receptor, which explains the intraocular pressure lowering effects of cannabis.
According to a Swiss study at the Clinic Montana, the effects of capsulated cannabis extract in 57 patients with multiple sclerosis were investigated. In this experiment, half of the patients received a placebo first and then the extract, while the other half received cannabis first. Muscle tone assessed with the Ashworth Scale was not significantly influenced by cannabis compared to placebo. But, the number of muscle spasms and the intensity of spasticity were reduced. The movement, which was measured with the Rivermead Mobility Index, was improved with cannabis.
According to the scientific journal "Frontiers in Psychiatry" administration of synthetic THC reduces symptoms of sleep apnea. Sleep apnea is a medical disorder characterized by frequent interruptions in breathing of up to ten seconds or more during sleep.
Overall recent clinical research shows that cannabis is effective in a wide range of symptoms. Effectiveness may also vary widely among patients. THC or cannabis does not necessarily mean it is the best medicine available for one symptom but the combination of several of its effects may be very useful in a range of chronic illnesses that often present with several symptoms. According to the Institute of Medicine, "In cases where symptoms are multi-faced, the combination of THC effects might provide a form of adjunctive therapy."