How Does Schizophrenia Develop?
Some scientists link the origin of schizophrenia to the development of cognitive and speech abilities in humans, even though the illness itself tends to suppress these abilities. The causes, development, and symptoms of schizophrenia are still widely debated: some believe it is passed down through a specific set of genes, while others see a connection to viral infections. However, doctors agree on one thing: the idea that schizophrenia is incurable is a myth. Let’s explore why schizophrenia is considered a disorder of speech, what secrets DNA may hold, and which symptoms can signal the onset of the illness.
Speech as a Side Effect
We don’t know who our distant ancestor was that first developed schizophrenia. But there is reason to believe that this person was skilled with stone tools, wrapped themselves in animal skins by the fire on cold evenings, and was just beginning to master the visual arts. This is suggested by a hypothesis from British psychiatrist Timothy Crow, who proposed that the emergence of schizophrenia is directly linked to the development of language.
Anthropologists call the appearance of speech in humans a genetic “event,” and its significance is hard to overestimate—language set us apart from all other animal species. Chromosomal changes that led to the development of language also caused asymmetry in the brain’s hemispheres: the left became responsible for analyzing and constructing speech, syntax, and morphology, while the right focused mainly on meaning. Crow’s idea is that this hemispheric asymmetry led to the emergence of schizophrenia. There is evidence for this: patients with schizophrenia often have less pronounced hemispheric asymmetry, which results in speech disorders.
The “independent life” of the brain’s hemispheres began about 100,000–250,000 years ago, during the Paleolithic era, when our ancestors were learning to draw the first patterns on cave walls. If Crow is correct, the first cases of schizophrenia appeared in those distant times.
However, Crow’s hypothesis is not the only one. One of his most prominent opponents, Jonathan Kenneth Burns, author of the evolutionary theory of schizophrenia, argues that the disorder is not linked to language, but to the development of cognitive abilities and social skills. Still, the “birth date” of the illness doesn’t change much in this scenario.
It’s important to note that these are just theories—unfortunately, the Rhodesian man of the Middle Paleolithic didn’t leave us a list of his illnesses. However, ancient Egyptians did mention symptoms resembling schizophrenia in their documents.
The name for this very old illness appeared relatively recently—in 1908, thanks to Swiss doctor Eugen Bleuler. He considered ambivalence—conflicting feelings and attitudes—to be the main symptom of schizophrenia. The Greek word for split or division is “schisis,” which is where the term “schizophrenia” comes from (the English version is closer to the original).
Genes, Infections, and Psychological Trauma
There are even more theories about why people develop schizophrenia than there are about its origins. According to the most popular current model—the biopsychosocial model—both biological and social-psychological factors play a role in the development of schizophrenia.
Biological causes include genetic anomalies, or heredity. Schizophrenia does not result from a single gene malfunction, but there are several genetic abnormalities that are often associated with the disorder. In fact, “candidate genes” are already well known to scientists. However, there is no clear and consistent “broken gene = illness” relationship. Some patients have no family history of the illness, while even if both parents have schizophrenia, the risk for their child is only 40%. If only one parent is affected, the risk drops to 6–10%. This is higher than the general population (where the prevalence is 0.7–0.8%, or 7–8 people per thousand), but still too low to claim a direct link.
Other biological factors include drug use (even “soft” drugs), pregnancy and birth complications, and infections contracted in early childhood. Some researchers also mention the impact of infections such as viral encephalitis. But beyond biological factors, social and psychological influences can also play a role. One of the most significant is family relationships. American anthropologist Gregory Bateson concluded that “double bind” communication in families—a situation where a child receives conflicting messages—can be a significant precondition for developing schizophrenia. For example, a father might verbally praise his son for chess club achievements, but nonverbally show disappointment that the boy didn’t join the soccer team. Children usually don’t ask for clarification and are left alone with this contradictory information, which can contribute to the development of schizophrenia.
Interestingly, for people at higher risk, even a minor event—like switching classes, moving, or a family argument—can be a “trigger.” The factors listed above are not exhaustive, and even the full list in academic literature is not complete—no one yet knows how to determine the risk for sure.
Symptoms
Schizophrenia consistently ranks second only to “delirium tremens” among the most feared psychiatric conditions. But what is it really? All symptoms of schizophrenia can be roughly divided into nine groups:
- Thought Echo
Thoughts no longer feel like the patient’s own—they can be taken away, reported, listened to, or even mentally answered by someone else. - Stolen Body
Thoughts, sensations, body parts, or even the whole body are believed to be stolen by someone else, who now controls them. - Radio in the Head
One of the most “popular” symptoms—voices in the head that comment, command, or judge. - Delusional Ideas
The patient may believe they or others are elves from a fantasy world, Freemasons, secret agents, aliens, or other characters. These ideas often come from news, books, or movies. - Hallucinations
Delusional ideas take on clearer forms. Hallucinations can be visual, auditory, olfactory, or tactile, and sometimes last for months. This also includes persistent “voices in the head.” - Disorganized Thinking
Thinking becomes blocked or interrupted, new thoughts start in the wrong place, and everything gets confused. The person loses the logical thread and can’t recall their previous reasoning. - Catatonia
This is complete immobility or stupor. The patient can be placed in any position and will remain that way. - Negative Symptoms
While the other symptoms add something to the person’s state, negative symptoms take away—work ability, emotions, and feelings. - Withdrawal
The patient becomes very withdrawn, stops responding to others, loses all previous interests and hobbies, and stops making plans for the future.
Schizophrenia has many forms and types, but one rule always applies: the diagnosis is made only if there is at least one clear or two “blurred” symptoms from points 1–4, or at least two symptoms from points 5–9. Importantly, the symptoms must persist for at least a month. Contrary to common myths, symptoms do not have to last a lifetime. Fourteen percent of patients recover within the first five years, about 20% experience only one episode in their lifetime, and another 20% achieve varying degrees of recovery.
The specifics of the illness’s manifestations may also depend on the era—recent years have seen “milder” symptoms in patients, and severe forms requiring mandatory hospitalization are much less common. There is a myth that people with schizophrenia are extremely dangerous to society—but in reality, the rate of offenses committed by these individuals is lower than that of people without the disorder.