Bipolar Disorder – Does Cannabis Help or Hurt?

There is nothing more controversial that the use of cannabis in patients with coexisting mental illness. Many studies suggest that cannabis use helps with the myriad symptoms of psychosis. Others seem convinced that marijuana use can worsen symptoms in schizophrenia while accelerating its course, and exacerbate bipolar and anxiety disorders. Others, of course, swear that cannabis reduces the clutches of panic attacks and anxiety.

Today I would like to update you on the use of medical marijuana and its effects on some psychotic disorders, in particular bipolar disorder using only the latest research.

Let’s first define what a bipolar disorder is and then proceed from there.

From WebMD:

Bipolar disorder, also known as manic depression, is a mental illness that brings severe high and low moods and changes in sleep, energy, thinking, and behavior.

People who have bipolar disorder can have periods in which they feel overly happy and energized and other periods of feeling very sad, hopeless, and sluggish. In between those periods, they usually feel normal. You can think of the highs and the lows as two “poles” of mood, which is why it’s called “bipolar” disorder.

The word “manic” describes the times when someone with bipolar disorder feels overly excited and confident. These feelings can also involve irritability and impulsive or reckless decision-making. About half of people during mania can also have delusions (believing things that aren’t true and that they can’t be talked out of) or hallucinations (seeing or hearing things that aren’t there).

“Hypomania” describes milder symptoms of mania, in which someone does not have delusions or hallucinations, and their high symptoms do not interfere with their everyday life.

The word “depressive” describes the times when the person feels very sad or depressed. Those symptoms are the same as those described in major depressive disorder or “clinical depression,” a condition in which someone never has manic or hypomanic episodes.

During the depressive phase patients will suffer typical symptoms of depression such as:

  • Sadness
  • Loss of energy
  • Feelings of hopelessness or worthlessness
  • Not enjoying things they once liked
  • Trouble concentrating
  • Uncontrollable crying
  • Trouble making decisions
  • Irritability
  • Needing more sleep
  • Insomnia
  • Appetite changes that make them lose or gain weight
  • Thoughts of death or suicide
  • Attempting suicide

In a publication from 2012, titled: ‘Cognitive and clinical outcomes associated with cannabis use in patients with bipolar I disorder’ by Raphael J. Braga, et al, some interesting finding were made.

In their discussion they noted:

Results from our analysis suggest that subjects with bipolar disorder and history of cannabis use disorders [CUD] demonstrate significantly better neurocognitive performance, particularly on measures of attention, processing speed, and working memory. These findings are consistent with a previous study that demonstrated that bipolar subjects with history of cannabis use had superior verbal fluency performance as compared to bipolar patients without a history of cannabis use (Ringen et al., 2010). Similar results have also been found in schizophrenia in several studies (Rabin et al., 2011). These data could be interpreted to suggest that cannabis use may have a beneficial effect on cognitive functioning in patients with severe psychiatric disorders.

The authors, who pretty clearly do not wish to admit their findings that cannabis may actually help some of these patients, offer another, different alternative interpretation.

The alternative explanation is that those patients with both CUD and bipolar disorder have better social skills because they are required to be fluent in speech in order to score marijuana from a dealer! That, the authors contend, may help explain the positive effects of cannabis on the brains of patients with these two simultaneously occurring disorders. Well, okay if you insist.

I however, find this explanation far too ad hoc for my liking. And it clearly makes little sense. They also found another interesting problem, that pot seems to make bipolar symptoms worse, yet not worse.

Although it appears that cannabis, at least in this study, intensified psychiatric symptoms, it simultaneously enabled these same patients better social skills. From the publication:

Interestingly, in that study social outcomes were only moderately affected by cannabis use, and in fact users engaged in more social activities than non users [sic] (van Rossum et al., 2009).

The researchers finished their discussion with this rather positive note:

Despite potential limitations, these analyses indicate an interesting pattern suggesting superior neurocognitive performance among bipolar patient[s] with comorbid CUD when compared to bipolar patients with history of cannabis use. Moreover, this cognitive advantage is noted in spite of evidence of a more severe clinical course. These results extend previous findings of similar studies reported in patients with schizophrenia and add significantly to the limited literature on cannabis use in bipolar illness.

I would like to clarify the above study somewhat. We have what amounts to a contradiction (which I didn’t delve into in the above quotations), when you read the entire study.

On one side the authors found that marijuana appears to make bipolar symptoms worse, while at the same time allows these same ‘worsened patients’ to be much more adept at social interactions, and social skills.

One of the hallmarks of psychosis is that patients generally lose their social attributes to a much greater extent than those without psychosis. It therefore seems unlikely that a patient who has degraded his or her psychotic symptoms would at the same time be better equipped at handling social interactions or improving social skills.

Perhaps the easiest way to interpret this data is to see pot as a drug that improves some very important aspects of bipolar disease while on the surface appears to worsen some ‘symptoms’ of bipolar illness such as intensifying either manic or depressive events.

Another study from Cambridge University press seems to support the benefits of cannabis in treating bipolar disorder but not schizophrenia. The title of this article is: ‘Opposite relationships between cannabis use and neurocognitive functioning in bipolar disorder and schizophrenia’ by P. A. Ringen, et al.

Without getting into the ‘sticky wicket’ of their methodology they conclude:

The findings suggest that cannabis use may be related to improved neurocognition in bipolar disorder and compromised neurocognition in schizophrenia. The results need to be replicated in independent samples, and may suggest different underlying disease mechanisms in the two disorders.

A 2014 study entitled:  Acute and Long-Term Effects of Cannabis Use: A Review by Karila, Laurent et al revealed this:

Cannabis can frequently have negative effects in its users, which may be amplified by certain demographic and/or psychosocial factors. Acute adverse effects include hyperemesis syndrome, impaired coordination and performance, anxiety, suicidal ideations/tendencies, and psychotic symptoms. Acute cannabis consumption is also associated with an increased risk of motor vehicle crashes, especially fatal collisions. Evidence indicates that frequent and prolonged use of cannabis can be detrimental to both mental and physical health. Chronic effects of cannabis use include mood disorders, exacerbation of psychotic disorders in vulnerable people, cannabis use disorders, withdrawal syndrome, neurocognitive impairments, cardiovascular and respiratory and other diseases.

After this review, they concluded that cannabis can indeed exacerbate psychosis in vulnerable people who use marijuana. The key word here is susceptible people. Normal, healthy people who use marijuana are not normally considered at higher risk than the general population.

However, the UK National Institute of Health Research published a recent (2016) meta-analysis (a study of all good quality studies available) in Lancet Psychiatry, covering all investigations on psychosis (including bipolar and schizophrenia) and marijuana use. They had this to say:

Continued cannabis use after onset of psychosis predicts adverse outcome, including higher relapse rates, longer hospital admissions, and more severe positive symptoms than for individuals who discontinue cannabis use and those who are non-users. These findings point to reductions in cannabis use as a crucial interventional target to improve outcome in patients with psychosis.

While many publications point to cannabis as an aid to those that suffer from psychosis, other data including the meta-analysis above, suggest the opposite.

I think it will take many more investigations into the complex world of cannabinoids and mental illness before we can conclude that pot is either good or bad for psychiatric patients.

The controversy continues.

Dr. Christopher Rasmussen
Dr. Christopher Rasmussen MD,MS, an anesthesiologist with a Master’s degree in traditional Chinese medicine, is a professor, lecturer, seminar provider, and world authority on preventive medicine.For more information on preventive medicine see


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