'Positive' and 'negative' symptoms

People who have a diagnosis of schizophrenia at times experience the symptoms of psychosis – delusions, hallucinations and muddled thinking. Mental health professionals describe these as the 'positive symptoms' of schizophrenia.

When people experience these symptoms, they are said to be having an 'episode' of psychosis. During an episode, people often do not feel unwell and do not think they have a mental health problem (mental health professionals call this 'lack of insight'). As a result, people who are experiencing the symptoms of psychosis may not want to ask for help or treatment.

Between episodes, people who have a diagnosis of schizophrenia often experience what mental health professionals call 'negative symptoms' and 'cognitive symptoms'. People may have little energy and lose the motivation to do anything; they may lose interest in friends, family members and activities they previously enjoyed. They may no longer care about their personal appearance and become socially isolated. They may experience memory problems and find it very hard to concentrate. It may be difficult to get up in the morning, let alone return to work or study.

In addition, people who have a diagnosis of schizophrenia often experience depression and can become very anxious.

The experiences and symptoms each person has will differ and last for different periods of time. Some people have just one episode of psychosis and are unwell for only a short period. Others go on to experience a number of episodes over a longer period of time. Some people will experience negative and cognitive symptoms in between episodes, or after a single episode, for months, or even years.

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Who develops schizophrenia?

People can develop schizophrenia at any age, but commonly men first become unwell in their late teens or early 20s. Women tend to develop schizophrenia when they are slightly older, in their late 20s. A small number of people develop schizophrenia in middle age or when they are older.

Anyone can get schizophrenia, though children of a parent who has the illness are slightly more likely to become unwell. Even though genes play a part in the development of schizophrenia, there is no single cause and there are many contributing factors (see What causes psychosis? page). Just because one person in the family has schizophrenia doesn’t mean that other family members will inevitably develop the illness. 

A review of research carried out between 1950 and 2009 in England showed that in each year, about 4 in every 1,000 people had a mental illness involving the symptoms of psychosis. Schizophrenia is the most common of this type of serious mental illness.

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When people first become unwell

Sometimes schizophrenia starts suddenly with an acute, and often frightening, episode of psychosis.

However, a first episode of psychosis is often preceded by what health professionals call a ‘prodromal period’ when people’s behaviour begins to change.

During this period, people are often depressed or anxious; they may find it difficult to concentrate or have problems remembering things. They may stop seeing their friends, act in a strange and uncharacteristic way, be less interested in study, work or hobbies, and care less about how they look. They may become socially withdrawn and spend much more time alone.

They also sometimes have experiences resembling the symptoms of psychosis – hearing voices every now and then, being occasionally suspicious and paranoid for example (see Paranoia page). However, not everyone who has these sorts of experiences will go on to have a first episode of psychosis (see Psychotic-like experiences page).

A large proportion of people who experience psychosis for the first time will get better with treatment (see below). Others will improve but may go on to have further episodes, or continue to experience negative or cognitive symptoms.

Research has shown that the earlier treatment is given for the symptoms of psychosis, the better people recover. People who don’t access mental health services when they first experience symptoms may get better slower, or be less likely to get completely better, and have an increased risk of relapse in the future (see Early intervention services page).

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When people first become unwell, it may not always be clear if they have schizophrenia or another serious mental illness that involves the symptoms of psychosis, such as bipolar disorder or schizoaffective disorder. Therefore, a diagnosis will not necessarily be given after a first episode of psychosis.

It is also not unusual for a diagnosis to change. Different diagnoses are given in response to symptoms an individual has at any particular time (see Mental health diagnoses page). 

There are different 'sub-types' of schizophrenia, determined by the most prominent symptoms. The most common sub-type diagnosis is 'paranoid schizophrenia': if someone is given this diagnosis, it means the symptoms they experience most are delusions and paranoia. Other sub-types of schizophrenia are rarely diagnosed.

There are two guides used by psychiatrists to help them make a diagnosis. One is called the International Classification of Diseases (ICD): it includes a special chapter on psychiatric illness and is published by the World Health Organisation (see Mental health diagnoses page). The section on 'Schizophrenia, schizotypal and delusional disorders' describes sub-type diagnoses.

The other guide is the Diagnostic and Statistical Manual of Mental Disorder (DSM) and is published by the American Psychiatric Association. A new updated version of the DSM was published in May 2013 (called DSM-5 because it is the fifth update) and abolished all the sub-types of schizophrenia it had described in previous iterations.

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Treatment and support

The quicker people who are experiencing an episode of psychosis receive treatment, the more likely they are to recover.

The 2014 National Institute for Health and Care Excellence (NICE) clinical guideline about the treatment of schizophrenia* recommends all people experiencing a first episode of psychosis be assessed straightaway and offered treatment and support by an early intervention team.

Someone who is experiencing another episode of psychosis may be offered treatment and support from a different type of specialist mental health team ­­– a crisis resolution/home treatment team, for example (see Mental health services page).

Sometimes people who are experiencing the symptoms of psychosis may need to be admitted to hospital for treatment (see Psychiatric wards and Mental Health Act pages).

Treatment for the 'positive' symptoms of schizophrenia consists of antipsychotic medication (see Antipsychotic medication page) that can diminish them, and sometimes make them go away completely. NICE recommends people be given a physical health check before they starting take antipsychotics and that potential side effects of a particular type of medication are discussed. People should start off on low doses (that can be increased if necessary) and have their general health monitored for the first three months.

Antipsychotic drugs don’t work for some people. Mental health professionals call their illness ‘treatment-resistant’, or ‘refractory’ schizophrenia.

NICE recommends that the antipsychotic clozapine be prescribed when people have not responded to two different types of medication – clozapine can suppress the symptoms of psychosis in people who have not got better after taking other antipsychotics. People who are prescribed clozapine must have regular blood tests and be monitored because this particular drug can damage white blood cells.

After an episode of psychosis, people will be encouraged to take antipsychotic medication for some time. If they stop taking the drugs too soon, the symptoms of psychosis may return. Some people will continue to take antipsychotics for many years – even for life – but this not the case for everyone who is given a diagnosis of schizophrenia. People should talk to the mental health professional who is offering them support before stopping antipsychotics, and come off them gradually.

There is currently no medication that effectively treats the negative and cognitive symptoms of psychosis – lack of attention and motivation, apathy, slow thinking, memory problems and difficulties interacting with other people and everyday situations. Cognitive behaviour therapy for psychosis has been proven to help improve these symptoms and other talking therapies are being developed and tested (see Other treatments  page).

NICE recommends people given a diagnosis of schizophrenia be offered cognitive behaviour therapy for psychosis and family therapy, and that mental health professionals should also consider offering arts therapies. However, these therapies are not available everywhere.

If people with schizophrenia experience depression and anxiety, they may also be prescribed antidepressants or medication that tackles anxiety. Sometimes people end up taking a large number of different drugs for different symptoms – or to counteract side effects of antipsychotics (see Antipsychotic medication page).

Family members and carers should be involved in planning care and support unless an individual does not want this to happen.

When someone has recovered from an episode of psychosis, they may continue to be offered support from an early intervention team or another type of community-based team, or their GP can take over. If someone becomes unwell again, however, a GP should not prescribe antipsychotics – they should refer them back to specialist mental health services.

* Psychosis and schizophrenia in adults, NICE clinical guideline 178, published February 2014.

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Peer support and self management

NICE also says that mental health professionals should consider offering 'peer support' from someone who has experienced the symptoms of psychosis, or has a diagnosis of schizophrenia, and who has trained to be a peer support worker. Alternatively, NICE says mental health professionals should consider offering a place on a 'self-management programme' led by a health or social care professional. Both peer support and self management aim to help people understand more about their symptoms and diagnosis, about their medication and treatment, about recovery and staying well and about what to do in a crisis.

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Physical health problems

People who have a diagnosis of schizophrenia are more likely to develop physical health problems, including weight gain, high blood pressure, heart disease and diabetes.

These problems are caused by changes in lifestyle as a result of the symptoms of the illness – research has shown that people who have a diagnosis of schizophrenia or another serious mental health condition tend to look after themselves less well, are more likely to smoke, and less likely to eat healthy food and take regular exercise.

Long-term use of antipsychotic medication can also lead to weight gain and increase the risk of cardiovascular disease and diabetes.

Research has shown that these physical health problems contribute to premature death: people who have a serious mental health problem like schizophrenia have shorter lives compared to the national average (some early deaths are because of suicide).

NICE says people should receive a health check before they start on antipsychotic medication, and be monitored for physical changes during the first three months of the new regime.

GPs should check the physical health of people who have a diagnosis of schizophrenia once a year, including their weight, blood pressure, blood sugar and cholesterol levels. People should be given treatment for any physical health problems and encouraged to raise any such problems with their GP.

People should also be offered advice about healthy eating and exercise, and help to stop smoking.

The charity Rethink Mental Illness has developed a 'Physical Health Check' designed to help mental health professionals make sure the physical health needs of people they support are addressed. Mental health professionals, family members and people with experience of schizophrenia can download the questionnaire free of charge from the Rethink Mental Illness website.

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A new name for schizophrenia?

Some researchers and people with personal experience of schizophrenia think that the name of the illness should be changed.

Those in favour of a new name say 'schizophrenia' is associated with discriminatory attitudes and stigma. They say the word, first used a century ago when nothing was known about the illness apart from its symptoms, is unsuitable because of today's greater scientific understanding of factors that contribute to its development.

The Japanese Society of Psychiatry and Neurology introduced a change in terminology in 2002: the name of the illness is now 'Togo ShitchoSho' (integration disorder). It was previously 'SeishinBunretsuByo' (mind split disease). The change was made 'to avoid stigma and better express the complexity of the disorder,' said the Society's president Masatoshi Takeda (July 2012).

A professor of psychiatry at Maastricht University in The Netherlands (Jim van Os) has suggested 'salience syndrome' may be an appropriate replacement for schizophrenia.

Members of the Dutch organisation Anoiksis, who have personal experience of schizophrenia, have suggested the term 'psychosis susceptibility syndrome', or PSS, and are now campaigning for its adoption.



This page was last updated on 22 March 2014
Links checked 5 July 2016


NICE (National Institute for Health and Care Excellence) clinical guideline on psychosis and schizophrenia in adults

This guideline was updated in 2014 and describes what treatment, care and support adults who experience the symptoms of psychosis or who are given a diagnosis of schizophrenia should be offered by the NHS. The guideline does not include recommendations about treatment for people who experience psychosis as a symptom of bipolar disorder, psychotic depression, dementia, Parkinson's disease or another condition. These recommendations are contained in other NICE guidance.


Understanding psychosis and schizophrenia: why people sometimes hear voices, believe things that others find strange, or appear out of touch with reality, and what can help

This report was published by the British Psychologoical Society's Division of Clinical Psychology at the end of November 2014.

It is written for people who have experienced psychosis, their friends, families, policymakers and journalists, and explains what is currently known about psychosis and schizophrenia. The report's authors include Professor Elizabeth Kuipers, who led the development of this website and other contributors to – Professor Daniel Freeman, Dr Emmanuelle Peters and Professor Mike Slade.

Download the report

Other useful websites

Schizophrenia Research Forum