Brain Primer

Schizophrenia: An Overview

  • Reviewed5 Jun 2023
  • Author Alison Davis
  • Source BrainFacts/SfN
Man with two faces beside him via Javier ki

While many psychiatric disorders impact a person’s behavior, mood, and cognition, most disorders don’t tend to significantly alter a person’s sensory reality. Schizophrenia, however, can bring on psychosis (e.g., hallucinations and delusions), flattened or blunted emotions, and impaired cognitive function.

Schizophrenia is a lifelong, severe psychiatric disorder that significantly alters thinking, emotion, and behavior. People with schizophrenia appear to others to have lost touch with reality. They experience “positive” symptoms such as hallucinations, delusions, and confused thinking, and “negative” ones, including an inability to experience pleasure and a severe lack of motivation. Like many psychiatric disorders that first emerge when the human brain matures in the late teens and early 20s, schizophrenia usually appears *between late teens to early 20s in males and early 20s to early 30s in females.

Although current medications do not provide a cure for schizophrenia, the combination of psychological treatments and medications provide the support needed for many people to pursue meaningful recovery goals. Chlorpromazine, the first antipsychotic drug, was developed in the 1950s as an anesthetic for surgery but was soon employed to calm people with psychiatric disorders including schizophrenia. Since then, more than 20 similar antipsychotic drugs have been developed. Most of these drugs work by dampening the dopamine response, which is thought to drive schizophrenia’s positive symptoms. For that reason, these medications may cause tremors and other movement-related side effects resembling Parkinson’s disease, which involves low dopamine activity. The most recently developed drugs also suppress some serotonergic activity, which seems to help with the negative symptoms of schizophrenia.

Scientists have known for many years, through studying twins and extended families with a history of schizophrenia, that this condition is highly influenced by heredity. With the emergence of powerful tools that scan massive amounts of DNA information, scientists in the last 15 to 20 years have been able to conduct hundreds of studies of gene association and risk for schizophrenia. Numerous genome-wide association studies have documented risk for schizophrenia typically involves many genes (more than 100) that each have a very small effect. Research continues to focus on learning more about genes that may impact schizophrenia, which affect nerve cell growth, development, learning, and memory. Genes with a proven relationship to schizophrenia are potential targets for new medications.

Adapted from the 8th edition of Brain Facts by Alison Davis.

*These age ranges were updated June 5, 2023, to reflect the most recent consensus from NIMH.



American Psychiatric Association. (2023). Diagnostic and Statistical Manual of Mental Disorders (5th ed., text rev.).

Bandelow, B., & Michaelis, S. (2015). Epidemiology of anxiety disorders in the 21st century. Dialogues in Cclinical Nneuroscience, 17(3), 327–335.

Burguière, E., Monteiro, P., Mallet, L., Feng, G., & Graybiel, A. M. (2015). Striatal circuits, habits, and implications for obsessive-compulsive disorder. Current Oopinion in Nneurobiology, 30, 59–65.

Craddock, N., & Sklar, P. (2013). Genetics of bipolar disorder. Lancet (London, England), 381(9878), 1654–1662.

Foland-Ross, L. C., Hamilton, P., Sacchet, M. D., Furman, D. J., Sherdell, L., & Gotlib, I. H. (2014). Activation of the medial prefrontal and posterior cingulate cortex during encoding of negative material predicts symptom worsening in major depression. Neuroreport, 25(5), 324–329.

Geddes, J. R., & Miklowitz, D. J. (2013). Treatment of bipolar disorder. Lancet (London, England), 381(9878), 1672–1682.

Kavanagh, D. H., Tansey, K. E., O'Donovan, M. C., & Owen, M. J. (2015). Schizophrenia genetics: emerging themes for a complex disorder. Molecular Ppsychiatry, 20(1), 72–76.

Memon, M. A. (2018). Panic Disorder. Medscape.

National Alliance on Mental Illness. (2017). Depression.

National Institute of Mental Health. (2017). Anxiety Disorders. NIH.

National Institute of Mental Health. (2017). Bipolar Disorder. NIH.

National Institute of Mental Health. (2017). Depression. NIH.

National Institute of Mental Health. (2017). Obsessive-Compulsive Disorder (OCD). NIH.

National Institute of Mental Health. (2017). Panic Disorder. NIH.

National Institute of Mental Health. (2017). Post-Traumatic Stress Disorder (PTSD). NIH.

Pittenger, C., & Bloch, M. H. (2014). Pharmacological treatment of obsessive-compulsive disorder. The Psychiatric Cclinics of North America, 37(3), 375–391.

Ragen, B. J., Seidel, J., Chollak, C., Pietrzak, R. H., & Neumeister, A. (2015). Investigational drugs under development for the treatment of PTSD. Expert Opinion on Investigational Drugs, 24(5), 659–672.

Strube, W., Bunse, T., Nitsche, M. A., Wobrock, T., Aborowa, R., Misewitsch, K., Herrmann, M., Falkai, P., & Hasan, A. (2015). Smoking restores impaired LTD-like plasticity in schizophrenia: a transcranial direct current stimulation study. Neuropsychopharmacology, 40(4), 822–830.

Treadway, M. T., Waskom, M. L., Dillon, D. G., Holmes, A. J., Park, M. T. M., Chakravarty, M. M., Dutra, S. J., Polli, F. E., Iosifescu, D. V., Fava, M., Gabrieli, J. D. E., & Pizzagalli, D. A. (2015). Illness progression, recent stress, and morphometry of hippocampal subfields and medial prefrontal cortex in major depression. Biological Psychiatry, 77(3), 285–294.

World Health Organization. (2022). Mental disorders. 

Research & Discoveries

See how discoveries in the lab have improved human health.

Read More

Image of the Week

Check out the Image of the Week Archive.


BrainFacts Book

Download a copy of the newest edition of the book, Brain Facts: A Primer on the Brain and Nervous System.