What is schizophrenia? Symptoms, causes and recovery
A diagnosis that describes a pattern of experiences, not a person.
Published 8 min read
Schizophrenia is a mental health condition that changes how a person perceives the world, thinks and feels. It does not touch one faculty and spare the rest. Perception, belief, motivation, emotion and the quiet certainty that one’s thoughts are one’s own can all be altered, usually over months rather than days. About 7 in 1,000 people develop schizophrenia at some point in their lives.1 For schizophrenia and related conditions, half of people first notice symptoms between the ages of 20 and 34, at the very moment when a life is being built.2
Few words in medicine carry as much history, or as much misunderstanding, as this one. Its story begins with a quarrel about a name.
It is 1908, and the Swiss psychiatrist Eugen Bleuler is about to give a familiar condition a new name.3
At the time, most psychiatrists called it dementia praecox, Latin for “premature dementia”. The name came from the German psychiatrist Emil Kraepelin. He had followed a large number of young patients over many years and found a common course: many of them ended in a severe decline of thinking and behaviour. To Kraepelin, this decline was what defined the condition, and he named it accordingly.4
Bleuler saw a different picture. Many of the patients in his care did not decline, and a name that promised dementia did not fit them. He wanted a name that described what happens inside the mind, rather than how the condition ends.4
He chose schizophrenia, from the Greek schizein, “to split”, and phrēn, “mind”. By splitting, he meant that the mind’s functions no longer formed a whole. Thoughts lost their usual connections to one another, and thinking, feeling and will no longer worked together as one. Bleuler regarded this loosening as the core of the condition. The hallucinations and delusions that others notice first were, in his view, secondary.5,4
Bleuler took phrēn to mean “mind”. But the word did not always mean that. In early Greek, it named a part of the body in the chest, and writers usually used it in its plural form, phrenes. Scholars still debate exactly which part: the midriff, the lungs or the chest more broadly.6
The phrenes were flesh, and they could be wounded. In the sixteenth book of the Iliad, Patroclus strikes the warrior Sarpedon “just where the midriff surrounds the ever-beating heart”, and when he pulls out his spear, the phrenes come out with it.7 They were very different from the psyche, the breath of life, which a dying warrior breathed out with his last gasp8 and which then “flitted down to the house of Hades”.7 The psyche departed for the underworld; the phrenes belonged to the body.
Yet the phrenes were also where a person thought and felt. The word appears in more than three hundred passages of Homer. People in Homer ponder, deliberate, devise plans and recognise things in their phrenes, and they rejoice, fear and grieve there too. As the classicist Shirley Sullivan notes, these activities combine intellectual, emotional and volitional aspects “commonly separated out in modern terminology”.9 The ancient word held thinking and feeling together, inside the body. Bleuler used it for a condition in which the two came apart, and this separation disturbed the mind of the person affected.
About a hundred years later, in 2010, Iris Sommer’s team in Utrecht scanned people with psychotic disorders as their voices began. In the seconds before each voice, activity dropped in the parahippocampal gyrus, part of the limbic system, which is involved in memory and emotion, and in the insula, which registers the state of the body. The researchers linked the finding to memory. Whether feeling, too, slips out of step at that moment, as Bleuler’s idea would suggest, is still an open question.10
Symptoms of schizophrenia
Modern psychiatry still sorts the symptoms into groups, though the emphasis has shifted since Bleuler. Researchers now speak of positive symptoms, negative symptoms and disorganisation, and they recognise difficulties with attention, memory and planning as a further part of the condition.11
Positive symptoms (opens in a new tab) take their name from a plus sign: something is added to ordinary perception and thought. The best known are hallucinations (opens in a new tab), such as hearing a voice that nobody nearby can hear, and delusions (opens in a new tab), firm beliefs that the people around the person do not share.
Negative symptoms (opens in a new tab) work like a minus sign: something is taken away. Motivation, pleasure in activities, the expression of emotion and the wish to be with others become harder to reach. They are less visible than hallucinations, and they are easily mistaken for laziness or indifference.
Disorganisation shows in speech and behaviour. Thoughts may jump between topics, and answers may drift away from the question. The combination of symptoms differs from person to person, and it can change over time.
How schizophrenia is diagnosed
There is still no blood test or brain scan that can show schizophrenia.12 None of the biological markers studied so far has proved sensitive and specific enough to serve as a diagnostic test.4 A psychiatrist makes the diagnosis after a careful assessment of the person’s experiences and history, often with information from people close to them, and after ruling out physical conditions and drug use that can cause similar symptoms.12
The criteria in the DSM-5-TR, a classification of mental health conditions, ask for three things. Characteristic symptoms must have been present for at least a month. Work, study, relationships or self-care must have declined. And signs of the condition must have lasted at least six months in total.12
Many people first meet a psychiatrist during an episode of psychosis (opens in a new tab). Psychosis is a state with many possible causes (opens in a new tab), and schizophrenia is only one of the diagnoses in which it occurs.
What causes schizophrenia
No single cause of schizophrenia has been found. Many small genetic differences add up to a predisposition (opens in a new tab), and what happens early in life shapes how that predisposition develops.11 Childhood trauma, poverty and growing up in a city are also linked to a higher risk.12
Treatment for schizophrenia
Modern drug treatment began in a Paris hospital. In 1952, at Sainte-Anne, the psychiatrists Jean Delay and Pierre Deniker began to give psychiatric patients a compound that had only just been introduced in anaesthesia: chlorpromazine. It became the first antipsychotic, and it started what historians call the psychopharmacological revolution.13
Today, the British NICE guideline recommends that the person and their psychiatrist choose an antipsychotic (opens in a new tab) together, after discussing its likely benefits and its side effects, such as weight gain and restlessness.14 Antipsychotics reduce hallucinations and delusions in many people, and they lower the risk of relapse. In trials that lasted 7 to 12 months, 24 in 100 people who continued their antipsychotic relapsed, compared with 61 in 100 who switched to a placebo.15 When symptoms persist after two different antipsychotics, NICE recommends clozapine (opens in a new tab).14
Medication is only part of treatment. NICE recommends cognitive behavioural therapy (opens in a new tab) for everyone with schizophrenia, family intervention for relatives who live with or are close to the person, and supported employment for people who want to work.14 In 32 trials, family intervention reduced the risk of relapse by almost half.16
Recovery and the long term
Bleuler’s quarrel with the word dementia was, at heart, a quarrel about the future. On that point the evidence has largely sided with him: a 2022 review in The Lancet notes that the outcome of schizophrenia is not uniformly poor.11
How often people recover depends on how recovery is defined. In a review of 50 studies, about 1 in 7 people met strict criteria: clear improvement in symptoms and in social life, lasting at least two years.17
Many people describe recovery differently. For them, it means building a life that feels meaningful, even if some symptoms remain. A review of 97 studies of personal recovery in mental health found five recurring elements: connection with others, hope, a sense of identity, meaning in life and empowerment.18
Schizophrenia and stigma
The diagnosis often brings a second burden: how other people respond to it. In a survey of 732 people with schizophrenia in 27 countries, almost half had experienced discrimination in making or keeping friends, and 72 in 100 felt they had to hide their diagnosis.19
The most persistent stereotype is that people with schizophrenia are dangerous. Studies do find a higher risk of violence among people with schizophrenia and related psychoses, but most of this excess is linked to drug and alcohol misuse. Among people who misuse drugs or alcohol, the risk is similar with or without a psychotic disorder.20 Schizophrenia does not usually cause a person to be violent.21
Some researchers and families argue that the name itself has become part of the problem. Japan has already changed the name. Until 2002, the Japanese term meant “mind-split disease”, and it carried such a negative image that many psychiatrists avoided it: instead of telling patients their diagnosis, they often told only the family.22 At the request of an association of patients’ families, the Japanese Society of Psychiatry and Neurology replaced the term in 2002 with “integration disorder”. Within three years, the share of patients who were told their diagnosis rose from about 37 to about 70 in 100.23 The rest were still not told, and this is not a Japanese habit alone: surveys in France, Germany and Italy have found that only a minority of psychiatrists tell their patients that they have schizophrenia.24
In the Netherlands, the Maastricht psychiatrists Sinan Guloksuz and Jim van Os have argued that schizophrenia should give way to a broader psychosis spectrum, which would better reflect how differently people’s lives unfold.25
To conclude, Bleuler named schizophrenia after a loosening between the mind’s functions, using a Greek word that once held thinking and feeling together. Research today describes a condition of the connections between perception, feeling and thought, with outcomes that vary widely, and that treatment, support and the attitudes of the people around someone all help to shape.
