Our findings

As well as having unusual thoughts or beliefs and having hallucinatory experiences, people with SZ can have difficulty relating to other people, experience low motivation, speak less often or less clearly, lose the ability to express emotions, and feel much less enjoyment in activities.

These experiences are often distressing and can impact one’s ability to function in daily life.

Another similar mental health condition is schizoaffective disorder, where people experience additional episodes of elevated and/or depressed mood, alongside psychosis.

Key findings

0.5 - 1%

 The amount of people that will develop SZ 


People that can show lasting improvement 

Top 10

SZ is in the top 10 causes of disability in developed countries


Approximately 0.5-1% of the population will develop SZ over their lifetime. The condition commonly begins in early adulthood between the ages of 15 to 25, with slightly earlier onset in men than women. Other mental health conditions often occur alongside SZ, including depression, anxiety and substance use disorders.

According to the World Health Organization, SZ is one of the top 10 causes of disability in developed countries worldwide. 

Possible causes

It is not currently known exactly what causes SZ. A commonly supported theory proposes that the condition arises through a combination of biological, psychological, and social factors. In particular, certain genes are thought to contribute to an increased risk of developing the condition, as well as changes in brain function.

Psychological and social factors are equally important, with a history of stressful or traumatic life experiences frequently associated with developing SZ.  It can also be triggered by the use of psychoactive substances, such as cannabis. 


People with SZ can vary in the symptoms they have. These include:  

  • Irrational or illogical beliefs  
  • Paranoia or suspicion of others  
  • Hearing voices or other modes of hallucinations  
  • Thinking difficulties, such as poor memory and decision making
  • Jumbled or disjointed thoughts or speech  
  • Feeling emotionally flat or dull
  • Difficulties with motivation, lack of interest or social withdrawal  

Treatment options

SZ is a treatable condition with up to 3 in 10 people showing lasting recovery, and 1 in 5 showing significant improvement. Treatment often involves a combination of medication, psychological therapy, and help with daily living skills.

This is most often managed in the community, to help people with SZ cope with their symptoms, and live independent and fulfilling lives.

Explore our other research themes

Contact the Centre for Mental Health

There are many ways to engage with us. Whether you’re a PhD student, media, or an organisation looking to form a partnership, contact the Centre on +61 3 9214 3865 or via cmh@swinburne.edu.au.

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