Introduction[edit | edit source]

Pyschosis is defined as a combination of psychiatric symptoms that cause a person to lose touch with reality. A person's ideas and perceptions are disturbed during a psychotic episode, and they could find it difficult to distinguish between what is true and what is not. Many medical, neurologic, neurodevelopmental, psychiatric, and neuropsychiatric disorders share psychosis as a common trait. Medical practitioners attempt to treat psychosis as their main therapeutic goal because it can cause patients and their loved ones great distress.[1]

Etiology[edit | edit source]

Substance abuse, primary psychiatric disorders, and other neurological or medical conditions can all lead to psychosis. First-episode psychotic disorders have been linked to anomalies in the brain, such as decreased prefrontal, superior, and medial temporal grey matter.[1][2] Though many times the emergence of psychotic symptoms and a full-blown illness correlate with environmental or epigenetic factors (substance abuse, stress, immigration, infection, postpartum period, or other medical causes), primary psychotic disorders are thought to be neurodevelopmental abnormalities and to develop in utero. There is strong evidence that the pathophysiology of psychotic illnesses involves genetic risk factors.[3]

Epidemiology[edit | edit source]

It is difficult to know the number of people who experience psychosis. However, In contrast to schizophrenia, which affects roughly 15 out of every 100,000 people, psychosis occurs about 50 times for every 100,000 people. For males, the peak age of onset is often in their teens to mid-20s, whereas for females, it typically occurs in their teens to late-20s. While early intervention is associated with better results, earlier onset is associated with worse consequences. Children rarely experience psychosis.[4]

Defining the term "Psychosis"[edit | edit source]

The primary source on psychiatric diagnoses, the Diagnostic and Statistical Manual, Fifth Edition (DSM-V), refrains from providing a precise description of "psychosis." Instead, it permits aberrations in any one of the following five categories to be used to characterize psychotic illnesses, whether primary or associated with medicine.  In a medical context, it will be helpful to keep these five categories in mind when the term "psychosis" is used.

  • Delusions
  • Hallucinations
  • Disorganized thought
  • Disorganized behavior
  • Negative symptoms[1]
  1. 1.0 1.1 1.2 Calabrese J, Al Khalili Y. Psychosis. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:
  2. Pantelis C, Velakoulis D, McGorry PD, Wood SJ, Suckling J, Phillips LJ, Yung AR, Bullmore ET, Brewer W, Soulsby B, Desmond P, McGuire PK. Neuroanatomical abnormalities before and after onset of psychosis: a cross-sectional and longitudinal MRI comparison. Lancet. 2003 Jan 25;361(9354):281-8.
  3. Cardno AG, Marshall EJ, Coid B, Macdonald AM, Ribchester TR, Davies NJ, Venturi P, Jones LA, Lewis SW, Sham PC, Gottesman II, Farmer AE, McGuffin P, Reveley AM, Murray RM. Heritability estimates for psychotic disorders: the Maudsley twin psychosis series. Arch Gen Psychiatry. 1999 Feb;56(2):162-8.
  4. McGrath J, Saha S, Welham J, El Saadi O, MacCauley C, Chant D. A systematic review of the incidence of schizophrenia: the distribution of rates and the influence of sex, urbanicity, migrant status and methodology. BMC Med. 2004 Apr 28;2:13.