Cannabinoids in the Treatment of Selected Mental Illnesses: Practical Approach and Overview of the Literature

Abstract

Although an increasing number of patients suffering from mental illnesses self-medicate with cannabis, current knowledge about the efficacy and safety of cannabis-based medicine in psychiatry is still extremely limited. So far, no cannabis-based finished product has been approved for the treatment of a mental illness. There is increasing evidence that cannabinoids may improve symptoms in autism spectrum disorder (ASD), Tourette syndrome (TS), anxiety disorders, and post-traumatic stress disorder (PTSD). According to surveys, patients often use cannabinoids to improve mood, sleep, and symptoms of attention deficit/hyperactivity disorder (ADHD). There is evidence suggesting that tetrahydrocannabinol (THC) and THC-containing cannabis extracts, such as nabiximols, can be used as substitutes in patients with cannabis use disorder.Preliminary evidence also suggests an involvement of the endocannabinoid system (ECS) in the pathophysiology of TS, ADHD, and PTSD. Since the ECS is the most important neuromodulatory system in the brain, it possibly induces beneficial effects of cannabinoids by alterations in other neurotransmitter systems. Finally, the ECS is an important stress management system. Thus, cannabinoids may improve symptoms in patients with mental illnesses by reducing stress.Practically, cannabis-based treatment in patients with psychiatric disorders does not differ from other indications. The starting dose of THC-containing products should be low (1–2.5 mg THC/day), and the dose should be up-titrated slowly (by 1–2.5 mg every 3–5 days). The average daily dose is 10–20 mg THC. In contrast, cannabidiol (CBD) is mainly used in high doses>400 mg/day.

Endocannabinoid System Changes throughout Life: Implications and Therapeutic Potential for Autism, ADHD, and Alzheimer’s Disease

“…Neurological disorders are a significant global public health issue due to their high prevalence, associated chronic disability, and severe impact on patients’ quality of life. Although the pathophysiology of these diseases is complex and not entirely understood, genetic, biological, and environmental factors are relevant to their appearance and progression [ 1 , 5 ]. There is increasing evidence of cannabinoids’ therapeutic potential on the behavioral impairments exhibited in neurodevelopmental and neurodegenerative disorders [ 5 ].…”

“…Although the pathophysiology of these diseases is complex and not entirely understood, genetic, biological, and environmental factors are relevant to their appearance and progression [ 1 , 5 ]. There is increasing evidence of cannabinoids’ therapeutic potential on the behavioral impairments exhibited in neurodevelopmental and neurodegenerative disorders [ 5 ].…”

“…Once the ECS plays a neuromodulator role in the central nervous system, ECS stimulation could influence neurological conditions, even if caused by changes in other neurotransmitter systems. In this way, CB1R agonists have been studied, due to their ability to modulate neuronal activity and neurotransmitter release [ 5 ]. CBD and CB2R agonists are also promising strategies for avoiding the psychoactive effects associated with CB1R stimulation.…”