Schizophrenia Causes, Signs, Symptoms & Side Effects

No one experiences schizophrenia the same way as someone else. Understanding the signs, symptoms and side effects of schizophrenia is a key component toward starting the recovery journey.

Understanding Schizophrenia

Learn about schizophrenia

Schizophrenia is a group of serious, incapacitating, and chronic disorders of the brain in which people begin to experience reality in an abnormal fashion. The symptoms of schizophrenia can involve a continuum of behaviors, thoughts, and emotional dysfunctions that can directly impact the way in which a person socially or occupationally functions.

People who have schizophrenia may have an abnormal affect such as laughing without a reason, depressed mood, being irrationally angry, or full of anxiety. They may also have abnormal sleep pattern and have a lack of interest in eating. Schizophrenia generally causes those it affects to experience a combination of delusions, hallucinations, patterns of disordered thinking, and irregular behaviors.

Delusions are fixed ideas that a person believes even after being disproven as untrue. These delusions may have a theme, such as somatic, religious, grandiose, erotomanic, nihilistic, referential, or persecutory. Persecutory delusions are the belief that someone is going to be hurt in some way by a group or individual. Referential delusions are the belief that certain comments, environmental factors, or gestures are aimed at the individual with schizophrenia. Grandiose delusions are the belief that one has superpowers, is descended from royalty, or is rich and famous. Somatic delusions are a preoccupation with health and organ functioning. Erotomanic delusions occur when a schizophrenic individual believes falsely that another person is in love with him or her. Finally, nihilistic delusions occur when an individual believes that a major catastrophe will occur.

Hallucinations are experiences of perception that occur in absence to a stimulus. These perceptions are vivid and clear, as though they are real and are uncontrollable. While hallucinations can occur among any of the senses, for people with schizophrenia, auditory hallucinations are the most common. Auditory hallucinations are often experienced as familiar or unfamiliar voices perceived as separate from one’s own thoughts.

Disorganized thinking is often showcased by the way an individual speaks. Someone who has schizophrenia may quickly switch from one topic to the next, sometimes to the point that the speech may be undecipherable to others. Questions that are asked may be answered in a somewhat or completely unrelated response.

Grossly disorganized or abnormal motor behavior may be manifested by a childlike goofiness or irregular agitation which can lead to challenges with functioning properly in society. Catatonic behavior is a form of abnormal behavior that is exhibited by many people with schizophrenia and involves a marked decrease in reactions to the environment.

Negative symptoms of schizophrenia are particularly prominent in those with schizophrenia – decreased expression of emotions and a decrease in purposeful motivated and self-initiated activities.

Many people who have schizophrenia must rely on their families and society at large for support as the cognitive challenges they face may be too great to allow them to care for themselves or hold down a job.

Most of the symptoms of schizophrenia begin to surface during the late teens and mid-thirties. The onset of the disorder may be abrupt or can occur over a long period of time. A small number of people who develop schizophrenia do recover completely while most need formal or informal supports of daily living.

While treatment can help to ease some of the symptoms of this disorder, most people with schizophrenia experience symptoms throughout their lifetime. However, many individuals struggling with this chronic disorder can live very gratifying and significant lives within their communities. Research into schizophrenia and the related disorders is ongoing to better understand the cause for the disorder in order to develop more effective treatment modalities.


Schizophrenia statistics

The lifetime prevalence for the development of schizophrenia varies by race and ethnicity, across countries, and by geographical origin and is approximately 0.3-0.7%.

Causes and Risk Factors

Causes and risk factors for schizophrenia

While it is uncertain what exactly causes schizophrenia, scientists generally believe that it is a combination of genetics and environmental factors. Some of the causes for schizophrenia may include:

Genetics: There is a genetic component to most mental illnesses such as schizophrenia. Many people who have schizophrenia have a first-degree relative with the disorder.

Biological: Older paternal age is a known risk factor for later development of schizophrenia in children. Many researchers believe that an imbalance in the cortex of the brain, interrelated chemical reactions involving dopamine and glutamate (two neurotransmitters) play a role in schizophrenia.

Environmental: Prenatal exposure to toxins, stress, maternal diabetes, viruses, and maternal malnutrition while in the womb during the first and second trimesters of pregnancy may increase the risk of developing schizophrenia. The incidence of schizophrenia is higher in children who grow up in an urban environment.

Psychological: A history of substance use and abuse, especially psychoactive drugs during adolescence and young adulthood is associated with a higher risk of developing schizophrenia.

Signs and Symptoms

Signs and symptoms of schizophrenia

Symptoms of schizophrenia can vary among individuals. However, there are a common set of symptoms that many people with schizophrenia exhibit. These include the following:


  • Appearing to lack emotion
  • Loss of motivation
  • Agitation
  • Depression
  • Suicidal thoughts
  • Anxiety


  • Reduction in ability to carry out activities
  • Social isolation
  • Neglecting personal hygiene
  • Problems with memory, especially short-term memory
  • Challenges paying attention
  • Trouble understanding information
  • Making up words
  • Speaking in a way that may make no sense to others
  • Answering questions with answers that make very little sense
  • Trouble focusing or paying attention
  • Violent behaviors


  • Repetitive motions
  • Catatonia – a state in which a person doesn’t move or respond to other people
  • Self-harm
  • Suicide
  • Insomnia


  • Disorganized behavior
  • Risky behaviors
  • Impulsive behaviors
  • Delusions
  • Hallucinations
  • Thought disorders
  • Grossly disorganized or abnormal motor behavior
  • Magical thinking
  • Psychosis


Effects of schizophrenia

If untreated, schizophrenia can lead to very devastating consequences that can impact every area of an individual’s life. The effects of schizophrenia may include:

  • Legal and financial problems
  • Poverty
  • Homelessness
  • Self-injury
  • Depression
  • Substance abuse
  • Family problems
  • Inability to work or go to school
  • Health problems related to antipsychotic medications
  • Heart disease
  • Being a victim of or perpetrator of a violent crime
  • Suicide

Co-Occurring Disorders

Schizophrenia and co-occurring disorders

Certain disorders frequently present simultaneously with schizophrenia, including:

  • Anxiety disorders
  • Substance use and abuse
  • Depression
  • Obsessive-compulsive behavior