So, as you can imagine, I have patients coming to me with a lot of worries about using marijuana medically.

Just the other day, a family member of a patient asked me,

Does marijuana use increase the risk of Depression?

Another version of this question is,

Does medical marijuana cause Depression?

What a great question!

And, the reason this particular person asked was because of his experience using pharmaceutical drugs in treating his own depression.  He found that some of the anti-depressants he tried actually made his depression symptoms worse.

I’m sure you’ve seen the TV ads for anti-depressants where they’re very quickly rattling off at the end, by the way, this medication may make the symptoms of your depression worse.  Or, it may even cause suicidal or homicidal thoughts.

Yea, that’s what this family member was referring to.

And, I’m sure if one person has that concern, so do others out there.

So I want to take some time to walk you through the results of 3 different studies done on marijuana and depression.  The results of these studies pretty accurately represent the results I’ve seen in the patients I’ve treated.


Marijuana and Depression: The Research

Marijuana and Depression: STUDY #1

Decreased depression in marijuana users.

A study published in 2006 surveyed 4400 adults

-those who used marijuana 7 days a week (daily marijuana users)

-those who used marijuana less than 1 day a week (weekly marijuana users)

-and those who never used marijuana (non-users)

The results showed that the daily and weekly marijuana users compared to the non-users reported

1.   LESS depressed mood

Depressed mood in this case was defined as

-not being able to shake off the blues even with help from my family or friends

-feeling depressed

-feeling lonely

-having crying spells

-feeling sad

So, again, the daily and weekly marijuana users reported feeling less of these symptoms.

2.  MORE positive affect

Positive affect in this case was defined as

-feeling just as good as other people

-feeling hopeful about the future

-enjoying life

Again, the daily and weekly marijuana users reported feeling more of these characteristics.

The results also showed that the weekly marijuana users compared to non-users reported experiencing

FEWER somatic complaints

Somatic complaints included

-feeling bothered by things that usually didn’t bother the participant

-having a poor appetite

-feeling like everything is an effort

-having restless sleep

-participants could not get going

Overall, the researchers concluded that the data suggested that the risk of depression is not increased in adults who use marijuana.

Marijuana and Depression: STUDY #2  

Marijuana use and depression among adults: Testing for causal associations.

Another study published in 2006 looked at the relationship between marijuana use and the development of depression years later down the line.

They researchers followed 8759 adults between the ages of 27 and 39 beginning in 1979 through 2002.  Over the years, these participants were asked about 1. their frequency and duration of marijuana use and 2. their mood.

Overall, they found that for every 100 participants, 23 of the marijuana users reported depression and 21 of the non-users reported depression.

Basically, the researchers concluded that marijuana use does not significantly predict depression later on in life.

Marijuana and Depression: STUDY #3  

Cannabis use and depression: a longitudinal study of a national cohort of Swedish conscripts.

In a similar study published in 2012, the researchers followed 45087 Swedish men.  They started by reviewing their military records when they were being drafted to see if they admitted or denied the use of marijuana.  The researchers then followed up on their hospital records over the next 35 years to check for a diagnosis of Depression.

They found that of the 45087 men, a total of 14% had used cannabis at the time they were drafted (so around age 18 to 20) and 2.5% had been diagnosed with Depression over the 35 years.

When they did some more statistical analysis on these numbers, they found there was no increased risk of future depression among those who had used marijuana between the ages of 18 to 20.

Marijuana and Depression:  The Results

There are patients that come to be that have been diagnosed with and are being treated for depression.  Then, there are patients that don’t have a diagnosis of depression anywhere on their chart nor do they report any symptoms of depression.

Basically, in both these groups of patients, I haven’t had reports that using marijuana medically has led to either symptoms of depression in those without a diagnosis of Depression or has worsened their existing symptoms in those with a diagnosis of Depression.

More specifically, they haven’t reported the symptoms of more depressed mood, less positive affect or any somatic complaints as I detailed in STUDY #1 above.

Alright I hope you’ve found this information helpful.




Marijuana and Depression: Research Referenced