The connection between cannabis use and mental disorders, especially schizophrenia, is supported by an incredible amount of scientific and medical evidence. However, despite this vast amount of data, experts still do not agree on whether marijuana cures or causes mental illness.
The most important connection between schizophrenia and marijuana is the endocannabinoid system. It is involved in neurotransmission and helps regulate important functions such as sleep and emotion recognition.
Why might marijuana be considered dangerous?
A typical argument against the legalization of marijuana is that its use is associated with an increased risk of psychosis. Although the cause is still not established, such critical and accusatory assumptions from the top stigmatize cannabis and put it in a bad light. This ignores the fact that people with psychotic disorders engage in a form of self-medication by devouring cannabis.
The most important connection between schizophrenia and marijuana is the endocannabinoid system. It participates in neurotransmission and helps regulate important functions such as sleep and emotion recognition. The endocannabinoid system is also responsible for reward and pleasure functions, both of which are pathological in schizophrenia patients.
The primary psychoactive component of marijuana, Δ9-tetrahydrocannabinol (THC), exerts its effects by binding to cannabinoid receptors in the endocannabinoid system. THC is one of approximately 80 different cannabinoid compounds found in cannabis, the vast majority of which do not cause any obstructive or psychologically altering effects.
Similarities of the condition after marijuana use and schizophrenia
Patients with schizophrenia have been shown to have increased levels of endogenous cannabinoids in both blood and cerebrospinal fluid. Neuroimaging studies and post-mortem tests have shown that patients have increased levels of cannabinoid receptors in their brains. As a result, people with schizophrenia suffer from:
- misinterpretation of reality memory impairment, malfunctioning cognitive and executive functions, and inability to process emotions.
Researchers have found that this condition is remarkably similar to that of high THC marijuana users.
These relationships can be observed at the behavioral level. A study published in the September 2015 issue of Schizophrenia Research and compiled by researchers at the Geisel School of Medicine at Dartmouth College and the Massachusetts Institute of Technology confirms that as many as 42% of schizophrenia patients behave like those who consume sizable amounts of THC-rich marijuana - such as seeing non-existent objects, spinning stories for hours, or completely shutting themselves off from the outside world.
In 2013, a study was conducted at an American hospital. Using MRI, images of the resting brain were taken from 12 people with schizophrenia. Through this, they observed that the circuit connections of the brain's reward system in the 12 patients who smoked marijuana were in better condition than is the case for patients who did not take the specific. They also found that connectivity increased in patients who were given THC through smoking or capsules.
One study that appeared in the Journal of Psychiatry & Neuroscience looked at the state of intercellular connectivity in 70 people, some of whom were control and study groups. They were also divided into those who do not take stimulants and those who take marijuana. The researchers then showed the subjects pleasant images. The results of the analysis confirmed that compared to the control group, those consuming THC products in any way showed a reduced response to pleasant stimuli. This in turn often leads to the development of depression and worsening of schizophrenia.
Due to the increase in schizophrenia patients and cannabis users, some experts have begun to investigate the role of the endocannabinoid system in the pathophysiology of the disease.
Does marijuana cause mental illness?
When it comes to the debate about whether cannabis use causes psychiatric symptoms or whether it should be used as a medication to alleviate symptoms, there are still no clear answers. Certainly, we should recognize that there is a common model for both behaviors, in which both mental illness and substance use can be causal to the development of pathology, such as the deficits in processing feelings of pleasure in the example above.
The results of another study published in 2014 suggest that a common genetic etiology may be at least partially responsible for the link between schizophrenia and marijuana use. For many patients, it may be the least consciously guided process in which their brain attempts to tune into the reward system in such a way as to create activities that immediately bring relief or joy - as is the case with smoking marijuana. Due to the increase in the number of schizophrenic patients and cannabis users, some experts have begun to investigate the role of the endocannabinoid system in the pathophysiology of the disease. They have begun to wonder if there are cannabinoids that can help manage certain symptoms of schizophrenia.
Many studies over the years have led us to believe that THC is the bad substance that leads to all the problems that come from marijuana use. But fortunately, there is also a whole range of cannabinoids that don't exhibit psychoactive effects, and among these, cannabidiol (CBD) has received the most attention from scientists. There is quite a bit of evidence that it has cell regenerative properties and may be a powerful ally in regulating the state of the endocannabinoid system in people with schizophrenia.
A group of German and Italian researchers, scientists at the University of California, conducted a double randomized clinical trial comparing the effects of cannabidiol with those of antipsychotic drugs. Their findings were reported in 2012 in Translational Psychiatry and showed that both treatments led to significant clinical improvements, but that cannabidiol caused fewer of the common side effects - including impaired concentration and weight gain - that generally always occur with antipsychotics.
These results need to be confirmed in larger clinical trials, but they are very promising. A series of studies has already been initiated in which patients with schizophrenia are given CBD and monitored through neuropsychological and neuroimaging tests.