Marijuana and Ritalin

Dear Alice,

I have ADHD and am prescribed 30 mg of Ritalin a day. However I also smoke pot at least once a week. Is it okay to be smoking while on Ritalin?

Dear Reader,

Kudos for taking the time to research the interactions of your medications! Mixing drugs can lead to unexpected (and sometimes negative) outcomes, so it’s a wise to stay informed. Unfortunately, there’s not a straightforward answer to your question yet. People use both marijuana (also commonly called pot or weed) and Ritalin, or methylphenidate (MPH), for medicinal and recreational purposes, even if those aren't the intended uses. While a fair amount is known about their separate effects on the body, the research on the combination of MPH and marijuana is sparse.

First, it might be useful to review some basic information about the two substances. MPH is a stimulant that acts on the central nervous system and is used to treat attention deficit hyperactivity disorder (ADHD). For people with ADHD, MPH may help them to focus or decrease restlessness. Tetrahydrocannabinol (THC) is the main active ingredient in marijuana, and it affects the dopamine centers in the brain to alter a person’s mood and senses. Marijuana may sometimes be used medicinally to treat issues such as nausea or anxiety, just as MPH is sometimes used recreationally as a study drug or at parties (though it's key to note this isn't one of its indicated uses). The desired effects of the two drugs are quite different, and they each have their own list of side effects. 

Some potential side effects of MPH are:

  • Stomach pain, nausea, or vomiting
  • Loss of appetite
  • Rapid heart rate
  • Sweating
  • Skin rash
  • Numbness, tingling, or cold feeling in the hands or feet
  • Insomnia
  • Hair loss

Some known side effects of pot are:

  • Rapid heart rate
  • Increased blood pressure
  • Increased rate of breathing
  • Red eyes
  • Dry mouth
  • Increased appetite
  • Slowed reaction time, cognitive impairment

Given the gaps in the research, the effects of combining THC and MPH are relatively unknown. A study of 16 participants, which observed the vital signs of the individuals and used self-report measures on sensations, found that the positive feelings many associate with MPH and THC use were amplified when the drugs were taken simultaneously. However, that same investigation found that the combination caused a higher heart rate than each of the drugs on their own. Additionally, a case study offered anecdotal evidence that the combined effects of THC and MPH could potentially contribute to manic episodes (feelings of being very energized, irritable, and active). While these studies hint at some positive and negative interactions between the two drugs, the lack of data on the subject makes it difficult to draw any solid conclusions.

There’s been more research into weed’s effect on ADHD, but the results have been similarly inconclusive. Some folks hold the belief that marijuana can be therapeutic for people with ADHD, but it has yet to be supported by the evidence. In fact, one study found that pot decreased performance when it came to attention, working memory, and verbal learning for people with ADHD. In terms of weed usage, there's conflicting evidence as to whether those diagnosed with ADHD engage in more or less weed usage than others. It has been found, however, that people with ADHD tend to use marijuana along with other substances.

Drugs, whether prescribed or not, tend to have the risk of unintended side effects, and combining drugs increases this risk. While there’s some information that points to negative consequences of combining weed and MPH, the scope and severity are still reasonably unknown. At the end of the day, it’s up to you to decide whether you feel comfortable mixing THC and MPH, given the limited and conflicting research. Health care providers often speak with patients about substance use, so if you're comfortable, you may want to talk with yours about your marijuana use and how it interacts with your medication. Being honest with them may help inform your treatment plan and ensure that you're getting the best possible care.

Last updated May 08, 2020
Originally published Jan 17, 2014

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