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Schizophrenia is a condition characterised by disturbances in a person's thoughts, perceptions, emotions and behaviour.  It affects approximately one in every 100 people worldwide and commonly begins in adolescence or early adulthood.  Schizophrenia is probably not a single disease, rather a cluster of diseases, which have overlapping signs and symptoms.  It is therefore important to acknowledge the unique experience of each person living with schizophrenia.

While schizophrenia can be a devastating illness for the people who experience it as well as for their families, it is important to recognise that there is hope.  Treatments, both medical and psychosocial, are becoming more effective.  Recently introduced early intervention programs are demonstrating encouraging outcomes for people with early psychosis and the concerns of consumers and their carers, such as those relating to empowerment and quality of life, are being increasingly recognised.

Schizophrenia is a complex disorder with few generalisations holding true for all people diagnosed.  In practice, there appears to be as many forms of schizophrenia as there are individuals experiencing the illness.



Possible causes of schizophrenia

The causes of mental illness are linked to several factors which can be summarised into three main groups:

Biological factors

  • which arise from physiology, biochemistry, genetic make-up and physical constitution and the drugs that they might abuse

Psychological factors

  • including the person's upbringing, emotional experiences and interactions with people

Social factors

  • that are associated with the person's present life situation and sociocultural influences


  • Exposure to stressors, both environmental and social may overwhelm a person's coping ability and may as a result contribute to the onset of mental illness.

No single cause of schizophrenia has been identified to date; there are most likely to be several contributing factors.  It is probable that there is an interaction between the consumer's biological vulnerability, stress or change in the environment and the consumer's ability to deal with these environmental factors in terms of their social skills and supports.  A less stressful environment may decrease the risk of onset in a person with a predisposition to schizophrenia or their relapse with another episode of the illness.

We know that schizophrenia is NOT caused by:

  • Domineering mothers or passive fathers

  • Poverty

  • Weakness of character or personality

  • Bad parenting

  • Sinful behaviour

Possible Contributing Factors:  

NB:  These are possible causal factors.  None, in their own right cause Schizophrenia.  They may, particularly in combination increase the risk of developing Schizophrenia.


Twin, family and adoptions studies suggest that genetic factors play an important role in the development of schizophrenia.  For example, the child of one parent with schizophrenia has about a 10 per cent chance of developing schizophrenia; if both parents have schizophrenia, the risk is increased to 40 per cent.  By comparison, the risk of schizophrenia in the general population is about one per cent.  The list below indicates the chances of developing schizophrenia during a life time:

  • General Population 1%

  • Brother or sister has schizophrenia 8-10%

  • One parent has schizophrenia 12-15%

  • Paternal twin has schizophrenia 14%

  • Identical twin has schizophrenia 50%

Schizophrenia has a large number of genes implicated in its cause (like other disease such as high blood pressure).   It is likely that no single gene “causes” schizophrenia.  Rather there is a large number of genes that increase the risk of getting schizophrenia.   These genes are important in different aspects of the way the brain develops and the way brain cells communicate to each other.  If an individual has a large number of these genes and is placed in a stressful environment this makes getting schizophrenia more likely.   Some of these genes also play a part in other severe psychiatric disease such as bipolar disorder.  This is one of the reasons that it can be difficult to diagnose these illnesses – they really do overlap.


Possible environmental factors include obstetric complications, the mother’s exposure to influenza during pregnancy or starvation.  It has also been suggested that stress, trauma even migration can lead to the emergence of schizophrenia.  Family factors causing stress may affect the course of the illness but there is no convincing evidence that they have a causative role.

Neurodevelopmental Factors

Schizophrenia appears to be a neurodevelopmental disorder.   That is the changes that cause the illness have been occurring from the earliest stages of development even in utero, and may continue to influence the development of the brain over the first 25 years of life.   This also means that we could influence or change the likelihood of getting the illness by identifying these factors and intervening early.   At present we are unable to do this satisfactorily. 

Drug Misuse

Substance misuse, including cannabis, is important in the development of schizophrenia in some people.  It is well established that substance misuse may precipitate or worsen the symptoms and interfere in the treatment of a person with schizophrenia. 

Biochemical Factors

The neurodevelopmental and genetic factors that we described above have an effect upon the development of the brain and the expression or amounts of many brain chemicals and neurotransmitters.  Neurotransmitters (the substances that allow communication between nerve cells) have long been thought to be involved in the development of schizophrenia and many of the treatments for schizophrenia affect neurotransmitter function.  Although there are no definitive answers yet, this is a very active area of schizophrenia research.



There are a number of signs and symptoms that are characteristic of schizophrenia, however, the expression of these symptoms varies greatly from one individual to another. No one symptom is common to all people. As such, diagnosis and treatment must always be tailored to the individual's unique experience of schizophrenia.


The symptoms of schizophrenia can be divided into a number of groups:

  • Positive symptoms, for example, hallucinations, delusions and disorganised thinking 

  • Negative symptoms, for example, loss of motivation and ability to experience pleasure in life

  • Cognitive symptoms, for example difficulty in concentrating or planning

  • Mood and anxiety - depression and anxiety is common

Positive symptoms

The positive symptoms of schizophrenia (also referred to as 'psychotic' or 'active' symptoms) reflect an excess or distortion of normal functioning and include the following:


Delusions are false personal beliefs held with extraordinary conviction in spite of what others believe and in spite of obvious proof or evidence to the contrary. They may revolve around many themes. For example, a person experiencing delusions may believe they are being spied on, tormented, followed or tricked (persecutory). Or they may believe gestures, comments, passages from books, television and other environmental cues are directed specifically at them (referential). Delusions may be bizarre (believing your thoughts have been removed by an outside force) or realistic (believing you are being followed by the police). Delusions will occur during some stage of the disorder in ninety percent of people who experience schizophrenia.


Hallucinations can occur in any of the five senses but the most common are auditory. These are usually experienced as voices which are perceived as distinct from the person's own thoughts. For example, the person may hear voices repeating or mimicking their thoughts, arguing, commenting on their actions (often in a critical manner) or telling them what to do (command hallucinations). Hallucinations of any form occur in over 70 per cent of people who experience psychotic illnesses. Auditory hallucinations occur in 60-90 per cent of people with schizophrenia, while visual hallucinations occur in 15-50 per cent.

Disorganised Thinking

This is usually expressed through abnormal spoken language. For example, the person's conversation jumps erratically from one topic to another, new words may be created, the grammatical structure of language breaks down and speech may greatly speed up or slow down.

Disorganised Behaviour

This can be manifested in a variety of ways. A person with schizophrenia may, for example, aimlessly wander, display child-like silliness or become unpredictable agitated. Or they may display behaviour that is considered inappropriate according to usual social norms, such as wearing many layers on a hot day, muttering aloud in public or inappropriately shouting or swearing. Disorganised behaviour can lead to problems in organising meals and maintaining hygiene. It may be difficult to link disorganised behaviour in adolescents to psychosis as teenagers are often intrinsically disorganised.

Catatonic Behaviour

This refers to states of muscular rigidity and immobility, stupor and negativism, or to states of wild excitement. The person may hold fixed or bizarre bodily postures for extended periods of time and resist any effort to be moved. Catatonic behaviour is very rare in developed countries (Cutting, 1996).

Negative symptoms

The negative symptoms of schizophrenia (also referred to as 'deficit' symptoms) reflect a loss of normal functioning and include the following:

Loss of Motivation (Avolition)

This may involve lack of energy, apathy or seeming absence of interest in what were usually routine activities. People experiencing avolition may be inattentive to grooming, personal hygiene, have difficulty making decisions and have difficulty persisting at work, school or household chores.

Loss of Feeling or an Inability to Experience Pleasure (Anhedonia)

This may manifest itself through having a lack of interest in social or recreational activities or through failure to develop close relationships. It may mean that the simple pleasures of life, like appreciating a beautiful sunset, being no longer enjoyed.

Poverty of Speech (Alogia)

The person's amount of speech is greatly reduced and tends to be vague or repetitious. People showing signs of alogia may be slow in responding to questions or not respond at all.

Flat Presentation (Affective Flattening)

This can be indicated by unchanging facial expressions, poor or no eye contact, reduced body language and decreased spontaneous movements. A person experiencing affective flattening may stare vacantly into space and speak in a flat, toneless voice. Flat affect refers to the outward expression of emotion and not the inner experience. this can be associated with a blunting of affect where people lose their sensitivity and ability to communicate emotion.

However, the negative symptoms are difficult to assess because they commonly precede an acute episode of illness and commonly persist. It is also possible a person may have schizophrenia but be symptom-free. The symptoms may only emerge during an acute episode.

Cognitive symptoms

Cognitive dysfunction is usually present in people with schizophrenia. A large body of research demonstrates schizophrenia is associated with cognitive impairments including problems with attention, concentration and memory. This is often associated with difficulties in understanding social relationships and understanding what the other people may be thinking. This is called social cognition.

Mood and Anxiety

People with schizophrenia commonly become depressed and anxious at stages of their illness. depression can be a reaction to being psychotic or it can arise without any identifiable stressor. It can also contribute to people being amotivated, tired and angry. Unfortunately a small number of people with schizophrenia commit suicide and this is usually linked with feeling depressed.

Anxiety can be a reaction to some of the positive symptoms of psychosis, part of the process of recovery or arise partly out of the socially isolated lives that many people with schizophrenia live. It can limit the ability of people to get out and engage with the community.

Are there any early warning signs?

Yes. Usually before a person develops psychosis or schizophrenia, there is a period where 'something is not quite right'. During this time they may withdraw from their family and friends, have changes in their appetite and sleep patterns, find it difficult to concentrate and consequently have difficulties at school or work. The person may find this period very disturbing, even frightening, and may not want to talk about what is happening to them. This period is referred to in medical language as the ‘prodrome’.

The prodrome is the period of disturbance or mild symptoms that occurs before the onset of an illness. The prodrome for schizophrenia can be anything from a month to several years. New research is suggesting that if early interventions are begun during this period, the prospects for recovery or a milder course of illness are increased.

Some early warning signs and symptoms of psychosis are:

  • Changes in thinking: Difficulty in concentrating, poor memory, preoccupation with odd ideas, increased suspiciousness.

  • Changes in mood: Lack of emotional response, rapid mood changes, inappropriate moods.

  • Changes in behaviour: Odd or unusual behaviour.

  • Physical changes: Sleep disturbances or excessive sleep and loss of energy.

  • Social changes: Withdrawal and isolation from family and friends.

  • Changes in functioning: Decline in school or work performance.

Remember: none of these symptoms by themselves indicate the presence of schizophrenia or another mental illness. But if they are severe, persistent or recurrent, professional help should be sought as soon as possible.




A diagnosis of schizophrenia does not necessarily mean that a life long illness is inevitable.  People do improve and recover. The assumption that people with schizophrenia are likely to experience a progressively worsening course of illness is not supported. Research reports a range of outcomes varying from full recovery to severe and continuous incapacity.  A significant proportion of people are able to achieve favourable outcomes.  Indeed, favourable outcomes (varying from having mild impairment to experiencing full recovery) have been estimated for 21% to 57% of people with schizophrenia.

Recovery will mean different things for different people.  It may mean 'complete' recovery in the sense of being symptom-free, or it may mean learning to live well with some residual symptoms of schizophrenia.

This information was sourced from

© 2015 by Walk Different


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