Cannabis Use Disrupts SSRIs for Anxiety, Depression

Published July 2021 | Journal of Personalized Medicine

Clinicians regularly prescribe selective serotonin reuptake inhibitors (SSRIs) to treat children and teens with anxiety and depression disorders. Meanwhile, many youths use cannabis recreationally while growing up.

The combination is not healthy, according to a study led by first author Samuel Vaughn, MD, PhD, and senior author Laura Ramsey, PhD, which shows that cannabis use can interfere with the benefits of SSRIs while increasing adverse events such as cough, fatigue, diarrhea, and dizziness.

The study presents a specific example of a 15-year-old female being treated for generalized anxiety disorder with panic attacks and recurrent depression. Her symptoms went into remission while treated with 10 mg a day of the SSRI escitalopram. However, over time, the panic attacks began increasing. As her physician increased the drug dosage to 15 mg and then 20 mg per day, the symptoms continued along with worsening nausea, headaches, and abdominal pain.

Unbeknownst to her clinician or parents, the patient had started consuming CBD/THC edibles. Once the usage was disclosed, and reduced, the girl began achieving improved symptom control with a reduced dose of escitalopram.

The study provides detail about how this drug-drug interaction affects the ability of the CYP2C19 enzyme to metabolize SSRIs in the liver, leading to excessive concentrations of the medication. This study did not evaluate SSRIs that rely on other metabolic enzymes.

The key takeaway, the co-authors say, is that more clinicians should inquire about CBD and THC usage to allow for better-informed dosing. To date, only a few clinicians who prescribe SSRIs to children also monitor SSRI plasma drug levels on a regular basis. The co-authors say a larger-scale study is needed to better understand the nuances of these emerging drug-drug interactions.