Anxiety / Depression

Anxiety and depression are widespread in Australia affecting up to 25% of the population. They are conditions with a multitude of causes and can occur on their own, but they also often accompany severe, chronic or life-threatening conditions. The endocannabinoid system has been implicated in many scientific studies as a mediator of anxiety and depression, as well as sleep, through its interaction with the neurotransmitter serotonin.

Medical Cannabis Treatment of Anxiety

Anxiolytic
Serotonin is an essential neurotransmitter involved in the regulation of mood, sleep, appetite and libido. In the central nervous system serotonin communicates with numerous receptors responsible for a variety of biological functions. The precise mechanism by which the endocannabinoid system modulates anxiety and depression is not fully understood. CBD is postulated to act as an agonist to the 5HT_1A receptor. Activation of the 5HT_1A receptor is understood to modulate the release of serotonin in the brain. In a study in which mice were pretreated with a 5HT_1A antagonist, the antidepressant effects of CBD were absent, confirming the hypothesis. Further evidence of the role of 5HT_1A is given by the observed similarities of CBD and isapirone (a 5HT_1A partial agonist) in a public speaking model. The procedure of the simulated public speaking model consist of subjects speaking in front of a video camera during which time physiological indicators of anxiety (heart rate, blood pressure and skin conductance) were measured. Patients were also asked to subjectively quantify their feelings of stress and anxiety.

Neuroprotection
Impairment of hippocampal neurogenesis has been associated with the pathogenesis of anxiety disorders and depression. CBD is thought to stimulate hippocampal neurogenesis, a property absent in CB1 knockout mice. Researchers postulate that the mechanism is CB1 dependent. CBD is thought to reduce the efficiency of FAAH and reduce anandamide reuptake; hence the CB1 receptor is activated.

Current Treatment
Medication is typically prescribed for the treatment of anxiety and depression. Studies indicate that the SSRI’s and tricyclic antidepressants are very effective treatments for depression and anxiety. For extreme circumstances where the patient is experiencing panic and high levels of anxiety, benzodiazepines may also be prescribed. It typically takes about three weeks for most antidepressants to take effect. It is suggested that alongside medication, patients receive therapy to talk out their issues with a professional. Cognitive behaviour therapy (CBT) and Interpersonal psychotherapy (IPT) works best for the treatment of anxiety and depression. Both SSRI’s and benzodiazepines have significant side effects while clinical studies suggest that CBD produces little to no adverse effects in the short or long term.

Pertinent Studies:
R de Mello Schier, A., P de Oliveira Ribeiro, N., S Coutinho, D., Machado, S., Arias-Carrian, O., A Crippa, J., … & C Silva, A. (2014). Antidepressant-Like and Anxiolytic-Like Effects of Cannabidiol: A Chemical Compound of Cannabis sativa. CNS & Neurological Disorders-Drug Targets (Formerly Current Drug Targets-CNS & Neurological Disorders), 13(6), 953-960.