This Special Report contains articles about cannabis use and its potential complications, including cannabis use disorder (CUD).
The first piece highlights the use of cannabinoids among the geriatric population. Cannabis and cannabidiol (CBD) use in older adults has become more prevalent as a result of reduced stigma; leniency in state restrictions on possession and sale; and advertisements touting benefits for chronic pain, peripheral neuropathy, stress, anxiety, depression, insomnia, headaches, and the adverse effects of chemotherapy. Medical marijuana use by individuals 65 and older has increased more than 8-fold in recent years. The article nicely summarizes how heavy marijuana use can cause mild functional and structural brain impairments, affecting attention, processing speed, motor coordination, verbal memory, and executive function. Overall, every older patient, along with their caregivers, should be queried as to their use of cannabis products. They should also be cautioned that those with preexisting neurocognitive impairment, such as Alzheimer disease, might be particularly vulnerable to adverse effects such as drowsiness, dizziness, fatigue, and mood changes.
We have a changing cultural ethos regarding cannabis acceptability; nevertheless, many users will suffer from its use. Some will develop CUD, and many can damage their educational achievement, work lives, health, and relationships. The next article in this Special Report includes an overview of clinical insights about the increasing number of cannabis users who experience negative effects, ranging from the annoying to the catastrophic. As noted, these effects arise from 3 sources: potential users’ sharply decreased perception of risk in recent years, easy availability of cannabis, and increased potency of Δ-9-tetrahydrocannabinol (THC) in legal and illegal cannabis sources. In recent years, THC concentrations in smoked cannabis doubled to 17.1% in 2017. Due to these high THC concentrations, clinicians need to recognize psychiatric complications of heavy repeated cannabis use, such as depression, anxiety, psychosis and, although rare, the cannabinoid hyperemesis syndrome.
Furthermore, although subtle compared with alcohol or opioid withdrawal, cannabis withdrawal does occur and includes irritability, anxiety, depression, insomnia, disturbing dreams, anorexia, abdominal pain, tremors, sweating, fever, chills, headache, and craving. Off-label use of medications for withdrawal are suggested and might include gabapentin and the THC analogue dronabinol, and limited amounts of benzodiazepines to relieve anxiety and insomnia. However, there has been little efficacy in the treatment of CUD.
The final article focuses on patients with schizophrenia. It synthesizes the large literature on cannabis and psychosis risk. The piece also reviews the literature on genetic associations, earlier age of onset, poorer treatment outcomes, and cognition. For example, a critical meta-analysis found an association between better cognitive performance and cannabis use in schizophrenia, a finding that merits careful replication because another analysis of first-episode schizophrenia found patients with psychosis and current cannabis use had significantly lower premorbid and current IQ scores.
We hope that you find that this educational Special Report enhances your understanding of the rapidly changing field of cannabinoids and their clinical implications, particularly for our geriatric population and patients with schizophrenia.
Dr Kosten is the Jay H. Waggoner Endowed Chair and co-founder at the Institute for Clinical and Translational Research. He is also a professor of psychiatry, neuroscience, pharmacology, and immunology at Baylor College of Medicine in Houston, Texas. Dr Verrico is an assistant professor of psychiatry research at Baylor College of Medicine. ❒