The history of research on cannabis and schizophrenia is a complicated one. Today, we understand that cannabinoids can have very powerful effects on the brain. We also know that cannabis contains many different compounds, all of which can affect our cognition differently. That’s why scientists believe that consuming the cannabinoid THC could be a risk factor in developing schizophrenia, and yet other cannabinoids like CBD could treat symptoms of this condition. So how does CBD affect our brain? And what do those effects mean for people with schizophrenia? Here’s what the latest research shows.
Schizophrenia is an incredibly complex psychiatric condition that affects brain function. The most prominent symptom of schizophrenia is that it causes a loss of connection with reality, causing people to experience delusions or hallucinations. This is known as psychosis.
But the symptoms of schizophrenia range much further than psychosis. It’s a condition that can affect all aspects of your life. Psychiatrists recognize three types of schizophrenia symptoms: positive, negative, and cognitive.
Positive symptoms are generally the easiest to recognize. They include symptoms of psychosis such as:
- Being delusional
- Speaking in an abnormal or disorganized manner
Schizophrenia also has negative symptoms, meaning symptoms characterized by a lack of something other people commonly experience. For example, these symptoms include:
- Loss of emotions
- Lack of motivation
- Loss of interest in life
Finally, schizophrenia affects brain function in a way that can cause cognitive losses. This can lead to:
- Memory loss
- Disorganized thinking
- Learning difficulties
- Lack of self-awareness
What are the five types of schizophrenia?
Although all people with schizophrenia will suffer from at least some symptoms from all three categories, psychiatrists also categorize schizophrenia into five different types.
Paranoid schizophrenia is characterized by strong delusions or hallucinations, and paranoia is the main positive symptom.
Hebephrenic schizophrenia is characterized by unusual speech and behavior, even in the absence of delusions and hallucinations.
Catatonic schizophrenia is characterized by stupor; loss of speech is one of the main symptoms.
Residual schizophrenia is when people exhibit schizophrenia symptoms that disappear completely with time.
Undifferentiated schizophrenia is the diagnosis given to people with schizophrenia symptoms that don’t fit into the other four categories.
What causes schizophrenia?
The scientific community is still unsure about what causes schizophrenia. People with this disorder exhibit a slightly different brain structure, as well as chemical imbalances. These probably come from a mixture of genetic and environmental factors.
We find that schizophrenia tends to run in certain families, so having a parent or family member with schizophrenia could be a factor for developing the condition.
Scientists believe that environmental factors also play a role. For example, high levels of stress and drug use are associated with developing schizophrenia. But whether they are actual causes or simply risk factors is still unclear.
Can schizophrenia go away? Understanding treatment options
Some people experience schizophrenia symptoms that go away with time (residual schizophrenia). However, this is rare. Most people who struggle with schizophrenia have the disorder for life. There is currently no cure for it, but certain forms of treatment can successfully manage its symptoms.
When someone is diagnosed with schizophrenia, they are usually given antipsychotic medications. Although it often takes a bit of time to find drugs they respond well to, antipsychotic medications can stop symptoms of psychosis-like hallucinations and delusions.
Other psychiatric drugs like antidepressants and anti-anxiety medications can also be used, helping with the negative symptoms of schizophrenia, and preventing common psychosis triggers.
Finally, different forms of therapy can help people with schizophrenia to cope with their symptoms in everyday life. Talking to someone can take some of the burdens off from the most painful symptoms of the condition. That’s why joining groups of other people with schizophrenia can also be useful. And therapy can also be a good way for people with schizophrenia to learn coping mechanisms, as well as the communication skills they may be lacking.
CBD and schizophrenia—what we know so far
The use of CBD in psychiatry is rapidly expanding. In the past couple of years, we’ve found that CBD could help people with symptoms of depression, anxiety, social anxiety and other mental health issues. What has been more surprising was the discovery that the molecule could help with even more severe symptoms, like psychosis. Clinical trials on people with schizophrenia are still few and far between. However, studies on animals and healthy volunteers show that CBD could help with some of the symptoms of schizophrenia. Here’s how it works.
What is CBD?
CBD, also known as cannabidiol, is classified as a cannabinoid compound, which is a type of molecule found in the cannabis plant and in the human body. These compounds can have powerful health benefits, due to their action on the endocannabinoid system (ECS).
The ECS is a vast biological system that regulates a number of important body functions. For example, it plays a key role in the management of pain, inflammation, appetite, nausea, and blood pressure. Cannabidiol acts on the ECS by binding with endocannabinoid receptors. When this reaction happens, it gives a boost to the endocannabinoid system, which can help to treat symptoms from countless conditions.
Because endocannabinoid receptors are located in the whole body, in the nervous system, and in the brain, cannabinoids can have benefits for all branches of medicine, including psychiatry.
CBD products that contain trace amounts of THC are now legal in most Western countries. In the United States, they are legal on a federal level but may be prohibited by certain states. CBD products are not approved by the FDA.
Is CBD good for schizophrenia?
There has been some controversy around the topic of cannabis and schizophrenia because the studies so far sometimes seem to contradict each other. For example, some studies show that cannabis can cause psychosis in healthy volunteers, while others show that it can actually combat it.
The key to the problem rests in making the distinction between different cannabinoids.
Consuming THC, which is the psychoactive molecule in marijuana, has sometimes been associated with greater odds of having schizophrenia.
But studies have actually found that consuming cannabis strains that are high in CBD results in fewer psychotic symptoms. This lets us know that even though the cannabis plant as a whole may not be appropriate for the treatment of schizophrenia, the CBD molecule could be beneficial.
Does CBD help psychosis?
Over the years, studies have found that CBD had antipsychotic effects. This 2012 review of 30 years of research on cannabidiol showed that both human and animal studies point toward one conclusion: CBD can relieve psychosis. We still don’t fully understand how this works, but the scientists behind the review concluded that the findings so far justify using CBD to treat schizophrenia, as well as other conditions characterized by psychosis.
So far, there have only been a few studies conducted on people with psychosis.
In 2006, a group of scientists administered daily doses of CBD to three people with treatment-resistant schizophrenia. They found that one of the three subjects experienced an improvement in their psychotic symptoms.
More recently, scientists conducted an experiment testing the effects of CBD used in conjunction with other schizophrenia medications. For this 2017 experiment, 88 patients received a high daily dose of CBD (1,000 mg) or a placebo for the duration of six weeks. By the end of the experiment, those who had taken CBD had a significant decrease in their psychotic symptoms, in comparison with the placebo control group.
Although these studies are still limited, they let us suggest that CBD could be helpful for people with schizophrenia, as it seems to lower psychotic symptoms.
What else can CBD do for schizophrenia patients?
Psychosis is not only the most obvious but also the most debilitating symptom of schizophrenia. Unfortunately, it’s not the only one. People with this condition also suffer from negative symptoms (lack of motivation and emotional flatness, for example) and cognitive impairments (memory loss and attention deficit).
Up to a quarter of people with schizophrenia suffer from depression. And even without a depression diagnosis, people with schizophrenia often struggle with depressive symptoms such as lack of motivation, and loss of interest in hobbies and social interaction. Several studies have found that CBD has antidepressant properties, which could also make it useful for schizophrenia patients with depressive symptoms.
Animal studies have shown that CBD has positive effects on cognition. For example, this 2017 study showed that taking CBD improved social interaction, recognition, and working memory in rats. We would need more human studies to confirm its benefits for the brain, but these studies are promising. They suggest that as well as lowering psychosis, CBD could also help people with schizophrenia function better in everyday life.
Finally, many people with schizophrenia report that stress can be a trigger of psychosis and particularly paranoia. When schizophrenia patients experience more anxiety in their lives, their delusions and hallucinations are likely to get worse. That’s why the fact that CBD reduces anxiety could make it even more useful for treating schizophrenia. It could not only treat and alleviate psychosis but also stop one of its more common triggers.
CBD—A new treatment for schizophrenia?
We’ve known about the anti-psychotic effects of CBD for years. But it’s only in the past two decades that we’ve had studies confirming the benefits of CBD for people with schizophrenia. According to research, it could lower levels of psychosis, either in conjunction with medication or on its own.
Not only that but CBD could also lower non-psychotic symptoms of schizophrenia, like cognitive impairments and depression.
Finally, CBD could lower stress and anxiety in people with schizophrenia, making them less likely to experience violent bouts of psychosis.
One of the best things about using CBD to treat schizophrenia is that it has a very good safety profile. As opposed to many antipsychotics, it’s generally well-tolerated and doesn’t cause significant changes in appetite, sleep, or attention. This means people with schizophrenia could use CBD on top of their usual medications without suffering from painful additional side effects.
Unfortunately, there are a couple of issues with these recent findings. The first is that there have only been a handful of studies conducted on people who actually have schizophrenia. The vast majority of the research has been done on animals or healthy volunteers.
The second issue is that clinical studies often use very high doses of CBD, above 1,000 mg per day per person. Although these studies have shown very good results, it may not actually be possible to prescribe such high doses to schizophrenia patients because of the cost factor. 1,000 mg of CBD would cost at the very least $70 and could go up to $200. This is a price few people would be able to afford daily.
CBD is one of the most promising natural treatments in the field of mental health and psychiatry today. With powerful antipsychotics, anti-anxiety, antidepressant,s and cognitive-enhancing effects, it could provide many benefits for people with schizophrenia. More research is still needed, but the data we have so far suggests that supplementing with CBD is a low-risk option that could provide significant relief from schizophrenia symptoms.
Cannabis and schizophrenia
2016 meta-analysis study on the connection between cannabis use and psychosis
2011 study on the connection between high-CBD cannabis on psychosis
CBD and schizophrenia
2012 review of studies on CBD and psychosis
2006 study on the effects of CBD on 3 patients with schizophrenia
2017 study on the effects of CBD on people with schizophrenia
CBD and depressive symptoms
2018 study on the effects of CBD against depression on mice
2014 study on the antidepressant effects of CBD
CBD and cognition
2017 study on the effects of CBD on social interaction, recognition, and working memory
CBD and stress or anxiety
2019 study on CBD for anxiety and sleep
2019 study on the effects of CBD for stress reduction
The safety profile of CBD
2017 study on the safety and side effects of CBD