Schizophrenia

Understanding Schizophrenia

Schizophrenia is a serious mental disorder that affects how a person thinks, perceives, feels and relates to others. It typically involves periods of psychosis, such as hearing voices or holding fixed false beliefs, alongside "negative" symptoms such as reduced motivation and emotional expression, and difficulties with attention, memory and planning. It usually begins between the late teens and early thirties, and its course varies greatly from person to person.

Despite a common misconception, schizophrenia does not mean "split personality". When Swiss psychiatrist Eugen Bleuler coined the term, he meant a splitting between thought, emotion and behavior. Multiple identity states are a feature of dissociative identity disorder, a different condition.

Key characteristics

Schizophrenia is heterogeneous: two people with the diagnosis may have quite different symptoms. Most experience at least one acute psychotic episode, often after a gradual period of change. Between episodes, some people return to their previous level of functioning, while others continue to experience symptoms, particularly negative and cognitive ones. Work, study, relationships and self-care can all be affected, and many people need some level of long-term support.

Prevalence and demographics

The World Health Organization estimates that schizophrenia affects about 24 million people worldwide, or roughly 1 in 300 people. Lifetime prevalence estimates generally fall between about 0.3% and 0.7%. It is diagnosed somewhat more often in men, who also tend to develop it earlier (typically late teens to mid-twenties) than women (typically late twenties to early thirties, with a second smaller peak around midlife). Schizophrenia occurs in every culture, but rates are higher in cities and among some migrant and minority groups, findings that point to social as well as biological influences.

Historical perspective

Stigma and misconceptions

Several myths persist. The belief that people with schizophrenia are typically violent is not supported: most are never violent, and people with severe mental illness are more likely to be victims of crime. The belief that recovery is impossible is also wrong; outcomes vary, and many people improve substantially. Finally, the mid-twentieth-century idea of the "schizophrenogenic mother", who supposedly caused the illness through cold or contradictory parenting, has been discredited and caused great harm to families. Family stress can affect the course of the illness, but upbringing does not cause schizophrenia.

Impact on individuals and society

Schizophrenia can bring distress from symptoms, side effects of treatment, stigma and social exclusion. It is associated with significantly reduced life expectancy: a 2017 meta-analysis by Carsten Hjorthøj and colleagues estimated an average of about 14.5 years of potential life lost, largely due to cardiovascular disease, smoking, metabolic effects, reduced access to physical health care and, in some cases, suicide. The lifetime risk of suicide is substantially higher than in the general population, often estimated at around 5%. Anyone in crisis should be directed to crisis resources. Families and carers also experience considerable stress.

Symptoms and Features

Clinicians usually group symptoms into positive, negative and cognitive domains, with mood symptoms and insight also important. These descriptions are educational; only a qualified professional can assess and diagnose.

Positive symptoms

Positive symptoms are experiences added to normal functioning.

Hallucinations are perceptions without an external source. Hearing voices is by far the most common type in schizophrenia; voices may comment, converse or command and are often critical or threatening. Visual, tactile, smell and taste hallucinations occur less often.

Delusions are fixed beliefs held despite clear contrary evidence and not explained by culture. Persecutory delusions (being watched, followed or plotted against) are most common. Others include referential delusions (believing neutral events carry personal messages), grandiose delusions, somatic delusions about the body, and experiences that thoughts are being inserted, withdrawn or broadcast, or that one's actions are controlled from outside.

Disorganized thinking and speech can include jumping between unrelated topics (derailment), answers that never return to the point (tangentiality), invented words, and in severe cases speech that is very hard to follow.

Grossly disorganized or catatonic behavior can range from unpredictable agitation or difficulty completing everyday tasks to catatonia, in which a person may become markedly unresponsive, hold unusual postures, or show purposeless excessive movement.

Negative symptoms

Negative symptoms are reductions in normal functioning, often summarised as five domains: reduced emotional expression (blunted affect), reduced speech (alogia), reduced ability to anticipate or experience pleasure (anhedonia), reduced motivation (avolition) and reduced social interest (asociality). These can be mistaken for laziness or depression. They are among the strongest predictors of everyday functioning and tend to respond less to medication than positive symptoms.

Cognitive symptoms

Many people with schizophrenia experience difficulties with working memory, attention, processing speed, planning and organisation (executive function), verbal learning and social cognition, meaning the ability to read others' intentions and emotions. These difficulties often begin before the first psychotic episode and strongly affect work and study.

Mood and anxiety symptoms

Depression and anxiety are common, both during and after psychotic episodes. Depression after an episode, sometimes called post-psychotic depression, is an important period for support because suicide risk can be elevated.

Insight and awareness

Some people with schizophrenia do not believe they are unwell, a phenomenon sometimes called anosognosia or reduced insight. Insight can vary across symptoms and over time and often improves with treatment and supportive relationships. Reduced insight is not stubbornness; it is thought to be partly a feature of the condition itself.

Causes and Risk Factors

Schizophrenia is understood as a neurodevelopmental condition in which inherited vulnerability interacts with environmental factors from before birth through adolescence. No single cause has been found.

Genetic factors

A meta-analysis of twin studies by Patrick Sullivan and colleagues (2003) estimated heritability at around 80%, meaning genetic differences explain much of the variation in risk in the populations studied. If an identical twin has schizophrenia, the other twin's risk is roughly 40–50%, which also shows that genes are not the whole story. Large genome-wide studies, starting with the Psychiatric Genomics Consortium's 2014 report of 108 associated regions, have since identified hundreds of genetic variants, each with a tiny effect. Rare deletions or duplications of DNA (copy number variants) carry larger risks. Genetic risk overlaps substantially with bipolar disorder and, to a lesser extent, with autism and depression.

Neurodevelopmental factors

Prenatal factors such as maternal infection, severe maternal stress or malnutrition, and obstetric complications are associated with modestly increased risk, as is older paternal age. Many people who later develop schizophrenia show subtle differences in childhood, such as slightly delayed motor development, social difficulties or lower school performance, although these signs are far too common and nonspecific to predict the condition.

Neurobiology

The dopamine hypothesis remains the most influential neurochemical theory. In its modern form, described by Oliver Howes and Shitij Kapur (2009), increased dopamine synthesis and release in certain pathways may cause ordinary experiences to feel unusually significant, a process called aberrant salience, which may underlie delusions and hallucinations. Reduced dopamine activity in frontal regions may contribute to negative and cognitive symptoms. Research also implicates the glutamate system, particularly reduced function of NMDA receptors, and GABA-related inhibitory signalling.

Brain imaging studies find average group differences, including enlarged ventricles, reduced grey matter in frontal and temporal regions, reduced hippocampal volume and altered connectivity. These differences are modest, overlap with healthy populations, and can be influenced by medication, substance use and lifestyle, so they cannot be used to diagnose individuals.

Environmental risk factors

• Urban upbringing: growing up in cities is associated with roughly double the risk compared with rural areas in several countries.
• Migration and minority status: first- and second-generation migrants, particularly those facing discrimination, show elevated rates, possibly linked to chronic social stress and "social defeat".
• Childhood adversity: abuse, neglect, bullying and other childhood trauma are associated with higher risk of psychotic experiences.
• Cannabis: frequent use, especially of high-potency cannabis and starting in adolescence, is associated with increased risk and earlier onset.
• Stressful life events: can precipitate episodes in vulnerable people.

Protective factors

Factors associated with lower risk or a better course include strong family and social support, good functioning before illness, later onset, avoiding cannabis and other drugs, and early access to comprehensive care.

Diagnosis and Assessment

DSM-5-TR diagnostic criteria

The DSM-5-TR describes schizophrenia as follows. Clinicians look for:

• A. Two or more of the following, each present for a significant portion of a one-month period (or less if successfully treated), with at least one being one of the first three: delusions; hallucinations; disorganized speech; grossly disorganized or catatonic behavior; negative symptoms.
• B. A marked decline in functioning in areas such as work, relationships or self-care, compared with before onset.
• C. Continuous signs of disturbance for at least six months, including at least one month of active-phase symptoms; the remaining time may involve milder (prodromal or residual) symptoms.
• D. Schizoaffective disorder and depressive or bipolar disorder with psychotic features have been ruled out.
• E. The disturbance is not due to a substance or another medical condition.
• F. If there is a history of autism or a childhood communication disorder, prominent delusions or hallucinations must also be present.

The DSM-5 removed the older subtypes (paranoid, disorganized, catatonic and others) in 2013 because they were unstable and had limited value. ICD-11 (code 6A20) uses similar criteria but requires symptoms for at least one month, and allows clinicians to rate the severity of different symptom domains.

Assessment process

Assessment usually involves a detailed clinical interview covering the timeline of symptoms, functioning before illness, family history, substance use, medical history, cultural context and risks to self or others. A mental status examination observes appearance, behavior, speech, mood, thought process and content, perception, cognition and insight. Rating scales such as the Positive and Negative Syndrome Scale (PANSS) and the Brief Psychiatric Rating Scale (BPRS) are used mainly to track symptoms over time and in research.

Medical workup

Because psychosis can be caused by medical conditions and substances, doctors typically carry out blood tests (for example, to check thyroid function, infection and general health), drug screening, and sometimes brain imaging, an EEG or neuropsychological testing, depending on the person's history and symptoms. See neuropsychological testing for more on cognitive assessment.

Differential diagnosis

Clinicians consider other psychotic disorders that differ mainly in duration or features: brief psychotic disorder (under one month), schizophreniform disorder (one to six months), schizoaffective disorder (prominent mood episodes) and delusional disorder (delusions without other major psychotic symptoms). Mood disorders with psychotic features, such as bipolar disorder, substance-induced psychosis, medical conditions such as autoimmune encephalitis, and early dementia also need to be ruled out. Our comparison of schizophrenia and schizoaffective disorder explores one common question.

Cultural considerations

Culture shapes how distress is expressed and understood. Beliefs about spirits, witchcraft or religious experiences may be normal within a person's community and are not delusions. Language barriers and misunderstanding can lead to misdiagnosis, and research in the US and UK has found that people from some ethnic minority groups are more likely to be diagnosed with schizophrenia, raising concerns about bias as well as real differences in social stress. Good practice involves interpreters, cultural consultation and attention to the person's own explanations.

Phases and Course

Prodromal phase

Many people experience a prodromal phase lasting months to years before a first episode. Changes can include social withdrawal, declining school or work performance, unusual beliefs or perceptions, suspiciousness, reduced emotional expression, disrupted sleep and difficulty concentrating. Researchers identify young people at "clinical high risk" using structured criteria; most do not go on to develop psychosis, but around a fifth to a third do within a few years, which is why early support services exist. See psychosis for more detail.

Acute phase

In the acute or active phase, positive symptoms are prominent and functioning is often severely affected. Some people need intensive support at home or a period in hospital. Episodes can last weeks to months.

Stabilisation and stable phases

As acute symptoms ease, people enter a period of stabilisation, when the risk of relapse is relatively high and continuing support is important. Later, in a more stable phase, positive symptoms may be minimal or absent, while negative and cognitive symptoms may persist to varying degrees. Rehabilitation, relapse prevention and quality of life become the main focus.

Long-term course

Long-term course varies greatly. Some people have a single episode or a few episodes with good recovery in between; others experience persistent symptoms. Long-term follow-up studies, such as Courtenay Harding's Vermont study of people discharged from hospital in the 1950s, found that many people improved considerably over decades, challenging Kraepelin's original pessimism.

Prognostic factors

Factors associated with better outcomes include later onset, a sudden onset with an identifiable trigger, good functioning before illness, strong social support, predominantly positive rather than negative symptoms, female sex, no substance use, a short duration of untreated psychosis and continued engagement with care. Factors associated with poorer outcomes include early and gradual onset, poor prior functioning, prominent negative and cognitive symptoms, substance use, social isolation and long delays before treatment. These are group-level patterns and do not determine any individual's future.

Treatment Approaches

Treatment aims to reduce symptoms and distress, prevent relapse, improve functioning and quality of life, address physical health, and support the person's own goals. The best outcomes are associated with combining medical, psychological and social support, ideally coordinated by a team.

Early intervention

Specialised early intervention services for first-episode psychosis, often lasting two to five years, combine careful medication management, individual and group therapy, family education, case management and supported education and employment. Trials such as the U.S. RAISE study have found better engagement, quality of life and symptom improvement than with usual care, particularly when treatment begins soon after symptoms start.

Acute and maintenance care

During acute episodes, the priorities are safety, stabilisation and building a trusting relationship with the care team. After stabilisation, ongoing care focuses on relapse prevention, regular review, managing side effects, physical health monitoring and psychosocial support. Decisions about long-term treatment are made collaboratively, weighing the person's preferences, experience of side effects and history of relapse.

Treatment settings

Most care takes place in the community, through outpatient clinics and community mental health teams. Hospital admission may be needed when there are serious safety concerns or a person cannot care for themselves. Partial hospitalisation or day programmes offer structured daily support while living at home. Assertive community treatment provides intensive, team-based support in the community for people with high needs, with staff available around the clock and small caseloads. See community mental health centers for how services are organised in the US.

Other physical treatments

Electroconvulsive therapy (ECT) is sometimes used for catatonia or when other treatments have not helped. Brain stimulation techniques such as transcranial magnetic stimulation are being studied, particularly for persistent voices and negative symptoms, with mixed results so far.

Antipsychotic Medications

Antipsychotic medications are a central part of treatment for most people with schizophrenia. This section explains what they are and what research shows; it is not guidance on choosing or using any medication, which is always a decision to make with a psychiatrist or doctor.

What antipsychotics are

The first antipsychotics were introduced in the 1950s and transformed psychiatric care. Medicines from this era are often called first-generation or "typical" antipsychotics. Second-generation or "atypical" antipsychotics, introduced from the 1990s onward, act on a broader range of brain receptors. All current antipsychotics act on dopamine signalling, in line with the dopamine hypothesis.

What research shows

Large meta-analyses show that antipsychotics reduce positive symptoms such as hallucinations and delusions in many people, and that continuing treatment after an episode substantially reduces the risk of relapse compared with stopping. Their effects on negative and cognitive symptoms are much more limited. Response varies between individuals, and finding a suitable medication can take time.

About a quarter to a third of people have treatment-resistant schizophrenia, meaning symptoms persist despite adequate trials of at least two medications. Guidelines recommend a particular antipsychotic with the strongest evidence for this group, which requires regular blood monitoring because of rare but serious side effects. Some medications are also available as long-acting injections given every few weeks or months, which some people prefer.

Side effects

Antipsychotics can have significant side effects, which differ between medications and individuals. These include movement-related effects (such as stiffness, tremor, restlessness and, with long-term use, involuntary movements called tardive dyskinesia), weight gain and metabolic changes that increase the risk of diabetes and heart disease, sedation, sexual side effects, and hormonal and heart rhythm changes. Regular monitoring of weight, blood sugar, cholesterol and other measures is recommended.

Side effects are a common reason people stop medication. Open conversations with prescribers, shared decision-making and attention to physical health can help. Stopping or changing medication without medical guidance can increase relapse risk, so any concerns are best discussed with the care team.

Psychosocial Interventions

Cognitive behavioral therapy for psychosis (CBTp)

CBTp helps people make sense of their experiences, examine distressing beliefs collaboratively, develop ways of coping with voices, and reduce distress and avoidance. Guidelines such as those from the UK's National Institute for Health and Care Excellence (NICE) recommend offering it. Meta-analyses show modest average benefits for symptoms and distress, with considerable variation. See cognitive behavioral therapy.

Supportive therapy

Supportive psychotherapy focuses on building a trusting relationship, offering emotional support and helping with practical problems. A strong therapeutic alliance is associated with better engagement across treatments.

Family interventions

Research beginning in the 1960s and 1970s by George Brown, John Wing and colleagues found that people returning to homes with high levels of criticism, hostility or emotional over-involvement, known as high expressed emotion, were more likely to relapse. A 1998 meta-analysis by Ronald Butzlaff and Jill Hooley confirmed this association. Importantly, this does not mean families cause schizophrenia; high expressed emotion often reflects the stress of caring without support. Family interventions that provide education, improve communication and problem-solving and support carers reduce relapse and hospital admissions and are among the best-evidenced psychosocial treatments. Multifamily groups, in which several families meet together, are another effective format.

Cognitive remediation

Cognitive remediation uses structured exercises, often computer-based, alongside coaching in strategies, to improve attention, memory and planning. Benefits for everyday functioning are greatest when combined with vocational rehabilitation.

Social skills training

Social skills training uses modelling, role-play and practice to build conversation, assertiveness and problem-solving skills for everyday life. See social skills.

Vocational rehabilitation

The Individual Placement and Support (IPS) model of supported employment helps people find competitive jobs quickly, based on their preferences, with ongoing support afterward and close links to the mental health team. Many trials show IPS roughly doubles employment rates compared with traditional vocational services. Supported education helps people return to study.

Peer support and self-management

Peer support workers draw on their own lived experience to offer hope, practical help and advocacy. Structured self-management programmes, such as Illness Management and Recovery and the Wellness Recovery Action Plan (WRAP), help people learn about their condition, recognise early warning signs, plan for crises and build coping skills.

Recovery and Rehabilitation

What recovery means

Recovery can be understood in several overlapping ways: clinical recovery (reduction or remission of symptoms), functional recovery (returning to work, study and relationships), social recovery (community participation) and personal recovery, a concept developed by people with lived experience that emphasises hope, identity, meaning and empowerment, whether or not some symptoms continue.

Recovery principles

Recovery-oriented services emphasise hope, person-centred goals, shared decision-making, a focus on strengths, attention to all areas of life, and respect for dignity and rights. They recognise that recovery is rarely linear and that setbacks are part of the process.

Rehabilitation services

Psychiatric rehabilitation helps people build skills for daily living and connect with community resources. Housing options range from supervised and supported housing to "Housing First" models that provide permanent housing without preconditions. Clubhouses, which offer a structured "work-ordered day" run jointly by members and staff, and other community programmes provide purpose and social connection.

Recovery outcomes

Outcome figures depend heavily on how recovery is defined. A 2013 meta-analysis by Erika Jääskeläinen and colleagues found that, using strict criteria requiring both clinical and social recovery sustained for at least two years, roughly 1 in 7 people met the definition. Using broader definitions, many more people show substantial improvement, live independently and pursue personal goals. Early intervention, continuous care, stable housing, meaningful activity and social support are associated with better outcomes, while stigma, poverty, homelessness, substance use and social isolation are major barriers.

Living with Schizophrenia

Daily management

Many people find that regular routines, consistent sleep, stress management, avoiding alcohol and drugs, staying physically active and keeping track of early warning signs help them stay well. Working with the care team on a medication routine that fits daily life, and raising side effects openly, supports long-term wellbeing. Attention to physical health, including smoking cessation support and regular health checks, is especially important given the higher rates of heart disease.

Building support networks

Supportive family and friends, peer support groups, community organisations and, for some people, faith communities can all provide connection and practical help. Educating loved ones about the condition can reduce misunderstanding and conflict.

Disclosure and stigma

Deciding whether and how to tell employers, friends or partners is a personal choice. In many countries, disability laws (such as the Americans with Disabilities Act in the US) protect against discrimination and allow for reasonable workplace adjustments. Internalised stigma, when people come to believe negative stereotypes about themselves, can be addressed in therapy and through peer support and advocacy.

Resources and support

Organisations that provide information and support include the National Alliance on Mental Illness (NAMI), whose Family-to-Family programme supports relatives, Mental Health America and the Brain & Behavior Research Foundation in the US, as well as national schizophrenia and mental health charities in other countries. Practical matters such as disability benefits, health coverage, advance directives and housing assistance are often handled with the help of a case manager or social worker. If someone is in crisis, see crisis resources for immediate help.

Family and caregiver support

Caring for someone with schizophrenia can be rewarding but also demanding. Carers benefit from education, support groups, respite care and attention to their own health. Our guide to caregiving offers more on looking after yourself while supporting someone else.

Criticisms and Debates

Schizophrenia remains one of the most debated diagnoses in psychiatry. Some researchers, such as psychologist Richard Bentall, argue that it groups together very different experiences and that studying specific symptoms, such as voices or paranoia, may be more useful. Others propose replacing the term altogether; Japan renamed the condition in 2002 to a term meaning "integration disorder" to reduce stigma. The psychosis-continuum research described on our psychosis page also challenges a sharp line between illness and health. Debates continue, too, about the best long-term use of medication and the balance between its benefits and side effects. These discussions are part of an active research field rather than reasons to dismiss the real difficulties people face.

Hope for the Future

Schizophrenia remains one of the most challenging mental health conditions, but understanding and care have changed dramatically. A diagnosis once seen as hopeless is now recognised as one with highly varied outcomes, in which many people achieve meaningful recovery.

Early intervention, coordinated care that combines medical, psychological and social support, and a recovery-oriented approach that respects people's own goals offer the best prospects. Research into genetics, brain development, cognition and new treatments continues. Just as important are reducing stigma and ensuring that people with schizophrenia are seen as people first, with the same rights to respect, opportunity and hope as anyone else. Anyone concerned about themselves or someone close can start with a doctor or a qualified mental health professional.