What Do We Really Know About Schizophrenia? | Karen Lankford, PhD, Neuroscientist at Yale University

Schizophrenia is a scary diagnosis and people understandably can often feel desperate to understand what is happening to their loved one and what they should do. In the modern era, this usually means turning to the internet to “do their own research”.

Unfortunately, however, while the internet does contain vast amount of information which can be at the fingertips of anyone with an internet connected device, the algorithms controlling search engines and social media sites are not designed to educate or inform users.

Artificially intelligent programs are not intelligent in the way the term is normally understood. They are mathematical programs which identify patterns in strings of digital data. They do not actually read or understand the content they present to users. Therefore, the accuracy and completeness of the information and the objectivity of the sources play no role in determining what content users are offered or in what order different content is presented. Instead, the algorithms used by Google, Facebook, Twitter, Tik Tok, etc. prioritize 3 things – (1) Content that someone has paid the company to put in front of you. Such content may not always be recognizable as advertisements, nor will the source always be obvious. What looks like a personal story of someone like you describing their journey from treatment to recovery, could be a slick piece of promotional material produced by a pharmaceutical company, the Church of Scientology, or a Russian hacking collective trying to direct you to a site that will put malware on your computer to steal your identity. (2) Content that a lot of other people have clicked on and interacted with. Generally, this means content which appeals to the lowest common denominator. The text will be written at the fourth-grade level and filled with snappy slogans and graphics that would be visually appealing to a toddler. Simple answers will be given to complex problems and little thought will be required of the reader. (3) Content which is similar to other content which you have previously selected. This is perhaps the most sinister aspect of these programs.

If you choose to read one article promoting a fringe theory or quack cure, the algorithms will show you more and more content which promotes these same ideas. You will not be directed to pages debunking such claims or be encouraged to delve more deeply into the subject to make a more informed decision about what to believe. The basic programing behind internet search engines and social media platforms cause them to function as nearly perfect Dunning-Kruger effect generators.

The Dunning-Kruger effect is a well-known psychological phenomenon where an individual who begins investigating a new field and reaches a certain basic level of understanding tends to develop an inflated opinion of his level of understanding and expertise. Unless pushed to delve more deeply into the topic, he will not be aware of how much he does not know and will be extremely confident of very ignorant conclusions. AIs direct most of their users to simple, easy to understand content and then further narrow the offerings to those most similar to whatever ideas they seem to prefer.

In short then, unless you already have a decent amount of background information about a subject, you will not know how to ask the kinds of questions which might lead to a real understanding. You will remain ignorant but become more and more confident that you know as much or even more than the supposed experts. When it comes to making critical decisions about mental health care, this kind of confident ignorance can be very dangerous.

As a prophylactic against readers going down a rabbit hole of misinformation about Schizophrenia on the internet, I am therefore offering a short summary of what the scientific field broadly knows, thinks it knows, and does not know about schizophrenia. Hopefully, this will inoculate readers with a degree of skepticism against some of the whackier ideas in circulation.

About 1% of the general adult population has schizophrenia and this prevalence is about the same in every country they have looked at, including both wealthy and highly industrialized countries and very poor third world nations. (Note that for the purposes of this post, I will be using the somewhat older and broader definition of schizophrenia. I am aware that mental illnesses with the same basic psychosis symptoms but slight differences in presentation or associated mental health symptoms are sometimes classified as different diseases, but most of the demographic studies did not make such fine distinctions.

Similarly, the probability of a child developing schizophrenia does not differ by socioeconomic status within individual countries. Prevalence does not differ by the educational level, marital status, religious affiliation, or parenting style of care givers. Rates are the same in rural, urban, and suburban communities.

It seems quite clear therefore that Schizophrenia is not caused by something the parents did or did not do, or by some chemical product of modern industry. All the afore mentioned factors do however affect the long-term prognosis for the disease.

One thing that has been consistently observed across studies was that the sooner the patient began receiving high quality mental health care treatment after the onset of symptoms, the better the outcomes. It seems that when patients initially experience hallucinations or delusions, they are aware that something is wrong with their thinking and that there are some gaps in their logic and inconsistencies between their ideas.

With time however, they find ways to rationalize the inconsistencies and fill in the gaps of their story. They create a story which they believe in with absolute conviction of a religious dogma. If the patient’s family is poor, does not speak English well, lives in a rural community with less access to mental health care professional or takes their child to an exorcist or faith healer, they are not likely to be diagnosed, let alone treated until the delusional ideas are firmly entrenched.

Although some street drugs can mimic the psychosis symptoms of schizophrenia, and some people with schizophrenia try to self-medicate their symptoms with drugs, drug use does not cause schizophrenia. Drug use can make symptoms worse, make the condition harder to diagnose and treat and is generally a bad idea, but it does not actually cause schizophrenia. After a period of detoxification, psychotic symptoms caused by drug use will dissipate. Schizophrenia does not just go away. There have been some studies suggesting that marijuana use might accelerate the onset of overt schizophrenia symptoms by six months to a year, but rates of schizophrenia were not increased by marijuana use and the relationship between symptom onset and drug use was not clear. It may be that individuals who experience anxiety symptoms associated with the onset of psychosis symptoms are more likely to enjoy the calming effects of marijuana.

Schizophrenia diagnoses are also unrelated to the patient’s general intelligence, specific skills, or major personality traits. Schizophrenia affects only a few very specific aspects of brain functioning and is not a generalized brain disorder. Once again, however, the level of intelligence and personality of the patient can have a significant effect on the long-term outcome. Individuals can use their own intelligence and reasoning capacity and/or trust in strong interpersonal relationships to recognize when then are drifting into delusional thought patterns and seek help before reaching a crisis.

We do not know for certain whether schizophrenia is one disease, or whether it actually represents several different diseases. This is not a problem unique to psychiatry. Many diagnoses are simply statements identifying which organ is affected and how, not the true cause of the symptoms. Pneumonia simply refers to inflammation in the lower part of the lungs where oxygen is exchanged. Pneumonia can be caused by pneumococcus bacteria, influenzas, COVID-19, or the dreaded “of unknown cause”. If the precise cause of the infection can be identified, there might be a specific treatment, but if not, there is a standard course of treatment that is followed based on the severity of symptoms. Since we do not yet know what causes schizophrenia, doctors just treat the symptoms as best as they can.

There is definitely a genetic component to schizophrenia as individuals who have close family members with the disease are significantly more likely to be diagnosed themselves. However, the inheritance pattern is not simple. There is no single gene or group of genes associated with schizophrenia. Rather, there are more than 200 genes associated with a 1 or 2% increased risk of schizophrenia distributed across many chromosomes.

Analysis of the functions of the many different genes associated with increased risk of schizophrenia has suggested a possible convergence of action in one specific process during development of the nervous system in which wiring connections are tested and incorrect connections are removed, while correct connections are stabilized. This is thought to result in a subtle wiring problem in regions of the brain involved in analyzing sensory information and ascribing meaning to it. In essence, it is thought that background noise in the system is not deleted, but instead becomes hyper processed, enhanced and ascribed great importance and meaning. Internal bodily sounds which are not supposed to reach your conscious mind become secret messages from divine or malevolent forces.

There is also a strong suspicion that the immune system plays a role in the course of the disease. Many of the genes linked to increased rates of schizophrenia play roles in development and regulation of both the nervous system and the immune system and many (certainly not all) sudden worsening of symptoms (AKA exacerbations) are associated with infections such as the flu or bronchitis lasting for several days.

For this reason, it is generally advised that individuals with schizophrenia stay up to date on all vaccinations, including influenza, and now COVID-19, and take daily supplemental antioxidant vitamin to reduce any neurological damage that might be caused by an overactive immune system response to infection. It has also been noted that both the severity of psychotic symptoms and the frequency of exacerbations tend to decline significantly in late middle age, when immune system functioning also begins to wane.

We know that dopaminergic neurotransmitter systems, and in particular D2 type dopamine receptors play a critical role in psychosis symptoms because drugs that target and block D2 type dopamine receptors can greatly reduce these symptoms in most patients with schizophrenia. We do not know however whether malfunctioning of the dopaminergic neurons or their connection are directly responsible for the psychotic symptoms, or whether are simply a key part of the way the symptoms are manifested. Are we just putting a large bucket under a leaky roof?

Antipsychotic drugs targeting the dopaminergic system do not seem to have any effects on other so called negative symptoms associated with schizophrenia such as lack of social engagement, flattened emotional responses and poor concentration. Furthermore, they rarely completely eliminate all hallucinations and delusions. They tend to make these symptoms weaker and less persistent, allowing patients to push them out of their conscious minds, rather than making them go away completely. Cognitive behavioral therapy plus medication provides better outcomes for the majority of patients than either medication or therapy alone.

The severity of psychotic symptoms varies greatly between individuals and fluctuates over time for individuals. Likewise, the efficacy of antipsychotic medication varies between individuals. Since D2 dopamine receptors are used in many different parts of the brain, medications targeting these receptors have a wide range of side effects. Many of these side effects can be managed, but for a small number of schizophrenia patients the negative side effects of medications outweighs the benefits.

Onset of recognizable psychosis symptoms typically begins in the teens or twenties. However, many adults who have been diagnosed with schizophrenia have indicated that they actually had begun to hear voices talking to them and had been acting on those voices as early as 6 or 7 years of age, but their behavior had not been recognized by the adults around them as abnormal. They had been thought to have had active imaginations, or simply been lying. There is a strong suspicion among neuroscientists that the underlying problem in schizophrenia is an error in fetal development which simply does not become apparent until further brain maturation. The changes in the brain occurring during puberty unmask the flaw by turning off some of the brain programs operating during childhood and forcing the adolescent brain to switch to a more sophisticated mode of analyzing the world which, in the case of an individual with schizophrenia is unfortunately operating with bad hardware.

We do not have any good information about the long-term prospects for individuals with schizophrenia. For some, symptoms remain well controlled after initial treatment and they live perfectly normal lives with families and careers. Others have multiple severe psychotic episodes and become homeless, confined to a mental hospital, or imprisoned. Given the strong stigma against the disease, those who are doing well, go to great pains to keep their diagnosis under wraps. As a society, we are therefore much more likely to see individuals with untreated or poorly treated mental illness, while the success stories remain invisible.

If there are two take aways that I hope readers get from this piece it is that if someone asserts that they
know with certainty what the right treatment or plan action should be for an individual with schizophrenia, they are lying to you, and if they try to say that doctors do not know anything about the
disease, they are also lying. Doctors know enough to make a good guess about treatment and to be able
to adjust their plan depending on how well it is working, but they cannot promise you that everything
will work out all right. The odds of someone leading a good quality life with medication and ongoing
therapy are much better than the odds of doing well without treatment. Doctors play the odds.