For more than 130 years, schizophrenia has been one of Western society’s most dreaded diseases, with those diagnosed suffering not only from its symptoms but also the terrible social stigma which accompanies it. According to the National Institute of Mental Health, 1.1% of the adult population of the United States – approximately 3,589,586 individuals – suffer from the disease.
Dr. Joseph Hayes, a clinical fellow in psychiatry at University College London, says negative perceptions of schizophrenia can have a direct impact on patients. “Some people definitely do internalize the shame associated with it. For someone already suffering from paranoia, to feel that people around you perceive you as strange or dangerous can compound things.
The general public’s lack of understanding regarding schizophrenia as a spectrum disease, much like autism, stems both from a lack of public education, and the fact that when schizophrenia is mentioned in the media or portrayed in a movie or on TV, it is usually its psychotic symptoms that are emphasized, and almost always linked to violence. This has created a false, and damaging, association in many people’s minds. The fact of the matter is that violence is not a symptom of schizophrenia, and schizophrenics, like most mentally ill people, are far more likely to be the victim of a violent crime than the perpetrator of one.
Worse still, schizophrenia is often conflated with multiple personality disorder. Alfred Hitchcock’s Psycho (1960) introduced the notion of a “split personality” to movie audiences, and the trope has since been used countless times, usually featuring at least one bloodthirsty and violent personality. M. Night Shyamalan’s 2016 psychological horror-thriller Split, whose main character has 24 different personalities, is just one example of the “crazy bad guy” archetype that informs many people’s understanding of what mental illness looks like.
Now, new research has the medical community re-evaluating schizophrenia’s status as a distinct disease, as well as the role an ingredient found in cannabis could play in treating some of its most intractable symptoms. But first, it is essential to have at least a broad understanding of what schizophrenia is, and how it works.
Most diseases are defined by their etiology (cause) and their pathogenesis (biological mechanism). However, schizophrenia is the rare disease defined solely by a collection of symptoms, because, while theories abound, its etiology and pathogenesis remain unknown.
The diverse collection of symptoms that define schizophrenia fall into three categories: positive/psychotic, negative/deficit, and cognitive/disorganization. The latter two, negative/deficit and cognitive/disorganization, are known as the prodromal symptoms, as they often appear before the more dramatic positive/psychotic symptoms most frequently associated with the disease.
Cognitive/Disorganizational symptoms include:
Negative/Deficit symptoms are the loss of things that healthy people typically have as the disease develops, and include:
These symptoms make holding a job, forming relationships, and other day-to-day functions especially tricky for people with schizophrenia.
According to the dopamine hypothesis of schizophrenia, the prodromal symptoms appear first because they occur slowly, throughout years and years, during which time the dopamine levels in the brain’s dorsolateral prefrontal cortex are shallow.
This long-term shortage of dopamine in the cortex manifests the negative/deficit and cognitive/disorganization symptoms, which become more and more exaggerated as time goes on, until at last, the positive/psychotic symptoms begin.
The positive/psychotic symptoms are triggered as the slow deterioration in the cortex finally reaches a point where the cortex loses control, and your nucleus accumbens are flooded with too much dopamine.
Your brain has mechanisms for bringing to your attention to things that are important. One explanation for schizophrenia is the malfunction of that mechanism, resulting in the brain incorrectly ranking unimportant things as necessary. Releasing dopamine into your nucleus accumbens is how your brain signals that something is salient, or essential. So, when the nucleus accumbens are deluged by dopamine, suddenly everything seems salient, resulting in schizophrenia’s psychotic symptoms.
Psychosis is not exclusive to schizophrenia and is a feature of many other mental and personality disorders, including bipolar disorder and unipolar psychotic depression. However, when you think of schizophrenia, chances are it is the disease’s positive/psychotic symptoms that spring to mind.
Positive/Psychotic symptom include:
Paranoid delusions and delusions of reference are both excellent examples of aberrant salience; someone suffering from these types of delusions is fundamentally unable to understand that the “signs” or individuals they believe to be a crucial part of some larger conspiracy are inconsequential stimuli and/or strangers being misinterpreted by their brain as important.
For more on the connection between cannabis and paranoia, check out A Look Into the Brain at How Weed Causes Paranoia
As defined by Wikipedia, antipsychotic drugs, also known as neuroleptics or major tranquilizers, are a class of medication primarily used to manage psychosis, including delusions, hallucinations, paranoia or disordered thought, principally in schizophrenia and bipolar disorder.
Before the advent of antipsychotics, the first generation of which was discovered in the early 1960s, nearly all people with full-blown schizophrenia had to be permanently locked up in psychiatric hospitals. Unfortunately, these medications are not without side effects, some of which are quite serious, particularly when they are used as a long-term form of treatment.
Simply, antipsychotic drugs work by blocking dopamine receptors. So, although a schizophrenic brain is continuing to over-produce dopamine, the drugs prevent the dopamine from being received by the nucleus accumbens, thereby reducing the psychotic symptoms.
However, while antipsychotic drugs are highly effective in treating the positive/psychotic symptoms of schizophrenia, they are unfortunately unable to repair the damage that occurs as a result of years and years of too little dopamine in the prefrontal cortex, and so can do little or nothing to address the disease’s negative/deficit and cognitive/disorganization symptoms.
In addition to being where the physical and psychological effects of cannabis are processed, the endocannabinoid system is a biological system that plays a variety of important roles in the human body, including regulation of many basic bodily functions, such as:
The key to cannabinoids’ antipsychotic properties is their role as neurotransmitters for the endocannabinoid system, which when properly targeted shows promise in addressing schizophrenia’s current treatment gap: providing relief for schizophrenia’s host of a negative/deficit and cognitive/disorganization symptoms.
Have you ever heard or read that smoking pot can induce a schizophrenic break? Chances are that you have, as it is a pet theory supported by a variety of cohort studies and widely embraced by segments of the medical community, as well as both fringe and mainstream media outlets.
The nature and cause of psychosis is a hotly debated issue, which continues to generate interest and attention. The Cannabis and Psychosis project is a national project of the Schizophrenia Society of Canada whose aim is to increase awareness and understanding of the relationship between cannabis use and psychosis from the perspective of youth. They have conducted an extensive analysis of various studies that look at the role cannabis does and does not play in the development of psychosis. They conclude:
Nevertheless, the evidence remains active for the claim that a pre-existing vulnerability to psychosis is a significant factor that influences the link between cannabis use and psychosis. Some studies have shown that once childhood psychotic symptoms are controlled, cannabis use no longer predicted the development and diagnosis of schizophreniform disorder and other psychosis-related illnesses (Arseneault et al., 2002). Accordingly, readers must consider this point to correctly interpret results in studies linking cannabis to psychosis.
Given the extensive evidence, it is relatively safe to say that cannabis use is not a necessary cause for psychosis as the statistics have failed to show that all adults with psychosis related illnesses used cannabis as a young person and nor is it a sufficient cause as the majority of adolescent users did not develop psychosis in adulthood. The most likely explanation is that cannabis is a component cause, among other possible causes which ultimately forms part of the causal constellation that leads to psychosis.
This elaborate, interactive explanation reflects our limited understanding of schizophrenia (and other psychosis-related illnesses) itself. There is evidence that both genetic and environmental factors are implicated but the exact origin is still relatively murky. For the present time, it is helpful to see cannabis as a modifiable risk factor both in individuals who are vulnerable to develop psychosis and in the time of the onset of psychosis.
The bottom line is that any blanket assertion that cannabis use causes schizophrenia is at best a gross overgeneralization of a complex issue in need of further rigorous, large-scale investigation and at worst, a blatant misrepresentation of facts. There is just not yet enough scientific data to definitively establish a causal link between smoking marijuana and developing schizophrenia, or in fact, the psychosis of any kind.
Interested in learning more? Read our article on The Connection Between Marijuana and Mental Illness
Regardless of the legal status of cannabis, many patients with psychiatric disorders use cannabis and report improvement in their symptoms. Patients use cannabis for symptoms of PTSD, anxiety disorders, depression, ADHD, bipolar disorder, chronic pain, insomnia, opiate dependence, and even schizophrenia. Also, patients use cannabis for neurological conditions such as the spasticity of multiple sclerosis, agitation in dementia, and specific seizure disorders that are unresponsive to standard therapies.
In an article over at The Conversation, Simon McCarthy-Jones, Associate Professor in Clinical Psychology and Neuropsychology at Trinity College Dublin, explains why the term “schizophrenia,” which Japan and South Korea have already abandoned, may soon be a thing of the past:
Arguments that schizophrenia is a distinct disease have been “fatally undermined”. Just as we now have the concept of autism spectrum disorder, psychosis (typically characterized by distressing hallucinations, delusions, and confused thoughts) is also argued to exist along a continuum and in degrees. Schizophrenia is the severe end of a spectrum or continuum of experiences.
Jim van Os, a professor of psychiatry at Maastricht University, has argued that we cannot shift to this new way of thinking without changing our language. As such, he proposes the term schizophrenia “should be abolished”. In its place, he suggests the concept of a psychosis spectrum disorder.
Another problem is that schizophrenia is portrayed as a “hopeless chronic brain disease”. As a result, some people given this diagnosis, and some parents, have been told cancer would have been preferable, as it would be easier to cure. Yet this view of schizophrenia is only possible by excluding people who do have positive outcomes. For example, some who recover are effectively told that “it mustn’t have been schizophrenia after all”.
Schizophrenia, when understood as a discrete, hopeless and deteriorating brain disease, argues van Os, “does not exist”.
Meanwhile, researchers at Houston Methodist believe that a significant number of people diagnosed with schizophrenia or bipolar disorder may have a treatable immune system condition.