Medicinal cannabis for the treatment of anxiety disorders: a narrative review

Purpose of review: Anxiety is a prevalent mental health condition which manifests as a disproportionate response of fear to a perceived threat. Different types of anxiety disorders vary in their pathophysiology, symptoms and treatments. The causes of anxiety disorders are complex and largely unknown; however, it has been suggested that a number of brain mechanisms and neurotransmitters are involved in the development of these conditions. While there are non-pharmacological treatments for anxiety, many patients are prescribed medications such as selective serotonin reuptake inhibitors, serotonin and noradrenaline reuptake inhibitors and/or benzodiazepines. Unfortunately, these medications have issues with efficacy and safety, and therefore, there is a continuing need for newer medicines. The cannabis constituents of tetrahydrocannabinol (THC), cannabidiol (CBD) and terpenes have been proposed as a potential treatment for anxiety conditions.

Recent findings: Medicinal cannabis constituents act on the endocannabinoid system (ECS) and other targets. The ECS affects several physiological functions through modulation of the central nervous system and inflammatory pathways. In particular, CBD has been suggested to exhibit anxiolytic properties, whereas THC can either have an anxiogenic or anxiolytic effect, depending on the dose, route of administration and individual genetic and environmental factors. There is also evidence that terpenes could be effective in anxiety management.

Summary: Currently, there is a gap in the literature as to whether standardised CBD and/or THC preparations can be used for anxiety disorders. Further information is required to know the precise doses and CBD-THC ratios from human clinical trials and real-world patient use.