Is cannabis bad for my mental health?

We’ll start by giving you the answer you’re probably expecting: it depends. 

Cannabis can present with so many opposite effects and this can be confusing.  This depends on so many factors within our bodies and the types of cannabis. It can make us relaxed or cause anxiety, improve or impair sleep, reduce nausea or cause vomiting, increased appetite or make us go off food… a sort of “yin and yang”. Getting the desired effect without any negative effects takes a lot of very careful consideration.

Let’s start by checking out the links between different groups of mental health symptoms. Much of the research until now has examined internalizing symptoms (for mental health issues that are difficult to see from the outside, and are experienced in a very inward way, such as depression, anxiety and post-traumatic stress disorder (PTSD) and externalizing symptoms (issues that are more apparent to other people, such as conduct or opposition problems, and sometimes attention deficit hyperactivity disorder (ADHD) is included here as well).

If we look at the general pattern between cannabis use and mental health issues, we see that overall, people who use cannabis are more likely to also experience difficulties with their mental health. The question then becomes “which one came first?”.

Externalizing systems are generally a predictor of later cannabis use. This doesn’t necessarily mean that because someone is very resistant to authority or rules, that in itself might make them go smoke a bunch of weed. There can be a lot of other important factors like the people they hang out with, their relationships with their family and teachers, and their performance at school. On the other hand, while some internalizing symptoms like depressive symptoms sometimes predict later cannabis use, there is more evidence for cannabis use predicting later internalizing symptoms, again particularly for depression, as well as psychosis. If you’re looking to learn more about psychosis specifically, we’ve covered risk factors (who’s more likely to develop psychosis linked to their cannabis use), harm reduction methods particularly for psychosis and cannabis, and recognizing the difference between a bad trip and an episode of psychosis.

Now, you might be wondering about the short-term effects, and what’s the deal with cannabis and anxiety? For now, not much is known for sure about short-term effects of cannabis on mental health, but there are some links between cannabis use and a reduction in certain types of memory during the next few days, and this could be frustrating to experience. Some people also feel less motivated, although this is still questionable as a research finding. If you’re feeling like your cannabis use might be affecting your mental health (in a positive or negative way), one thing you can do is keep a journal of how you feel every day, while noting the times when you’re using weed. Don’t forget to note details of your sleep, appetite, mood, social interaction and use of other things like alcohol in your journal. An added benefit is that some people find that this practice – keeping a journal – in itself helps them with their mental health!