Adding an Antidepressant to Therapy Did Not Help People Quit Cannabis | Research

The takeaway

In a double-blind trial of 52 cannabis-dependent users, adding escitalopram (an SSRI) to cognitive-behavioral therapy did not improve abstinence rates, anxiety, or depression compared to placebo.

Read this if you are trying to quit cannabis and wondering whether antidepressants could help.

Only 19% abstinent at 9 weeks; SSRI provided no additional benefit over therapy alone

What the researchers found

Cannabis-dependent users received 9 weeks of weekly CBT and motivational enhancement therapy along with either escitalopram (10 mg/day) or placebo. The dropout rate was high at 50%. Among the 52 patients in the intention-to-treat analysis, only 10 (19%) remained abstinent at 9 weeks.

Escitalopram provided no advantage over placebo for cannabis abstinence rates, anxiety scores, or depression scores during withdrawal and abstinence. The authors note that the low overall abstinence rate and high dropout limited their ability to fully assess anxiety and depression outcomes.

Despite the null result, the authors caution against concluding that SSRIs are definitively ineffective for cannabis withdrawal, given the study's limitations.

Why it matters

Cannabis dependence treatment remains challenging, and many cannabis users have co-occurring mood symptoms. This study tested whether addressing potential underlying depression and anxiety with an SSRI would improve quit outcomes. The null result informs treatment planning but does not close the door on pharmacological support.

The numbers in context

52 participants. 9-week treatment. 50% dropout rate. 19% abstinent at 9 weeks. No difference between escitalopram and placebo on any outcome.

How the study worked

This was a double-blind, placebo-controlled trial. 52 cannabis-dependent individuals were randomized to receive escitalopram (10 mg/day) or placebo for 9 weeks alongside weekly CBT and motivational enhancement therapy. Urine samples monitored THC levels, and questionnaires assessed anxiety and depression.

What this study cannot tell us

The high dropout rate (50%) severely limited statistical power. Only 19% achieved abstinence, meaning anxiety and depression measures were assessed in mostly active users. The sample size was small. Escitalopram dosing (10 mg/day) may have been insufficient for some patients.

How to read the evidence

This is a double-blind RCT, but the high dropout rate and small sample limit the conclusions that can be drawn.

When this study was published

Published in 2014. The search for effective pharmacological treatments for cannabis dependence continues.

The bigger picture

No medication has been consistently shown to help with cannabis dependence. This study adds escitalopram to the list of failed pharmacological approaches. The high dropout rate (50%) underscores the difficulty of treating cannabis dependence and the need for better engagement strategies.

Questions still open

Would higher SSRI doses or different antidepressants show different results? Is the 50% dropout rate an inherent challenge of cannabis treatment trials? Would engagement-focused interventions reduce dropout?

Common questions

Why did so many people drop out?

Cannabis dependence treatment trials typically have high dropout rates. Contributing factors may include ambivalence about quitting, withdrawal symptoms, return to use environments, and the perceived low severity of cannabis compared to other substances.

Are any medications proven to help with cannabis quitting?

As of this study, no medication had been consistently shown to improve cannabis cessation outcomes. Behavioral therapies (CBT, motivational enhancement) remain the mainstay of treatment. Some research has explored gabapentin, NAC, and dronabinol with mixed results.

Read the original research

Treatment of cannabis dependence using escitalopram in combination with cognitive-behavior therapy: a double-blind placebo-controlled study.

The American journal of drug and alcohol abuse, 40(1), 16-22

View on PubMed ↗Publisher’s paper ↗

Citation

Weinstein, A M; Miller, H; Bluvstein, I; Rapoport, E; Schreiber, S; Bar-Hamburger, R; Bloch, M. (2014). Treatment of cannabis dependence using escitalopram in combination with cognitive-behavior therapy: a double-blind placebo-controlled study.. The American journal of drug and alcohol abuse, 40(1), 16-22. https://doi.org/10.3109/00952990.2013.819362