Psychosis is a syndrome associated with abnormal functioning of the frontal and temporal lobes and the dopaminergic and serotoninergic projections to these areas. People with psychosis may experience hallucinations (e.g., auditory, visual, tactile), delusions, and disorganised thoughts and actions.
Psychosis can be due to primary psychiatric disorders or can be secondary to substance use or specific medical aetiologies. Primary psychotic disorders include schizophrenia, delusional disorder, schizoaffective disorder, schizophreniform disorder, and brief psychotic disorder. A psychotic syndrome may also accompany other psychiatric conditions such as major depressive disorder and bipolar disorder. Patients with psychosis associated with psychiatric disorders present with a combination of hallucinations (mostly auditory), delusions, and disorganised thought process, but are usually oriented and have minimal overt cognitive deficits. With the exception of acute agitation, patients with psychosis (who are otherwise healthy) tend to have normal vital signs. Patients with psychosis secondary to drug use or medical causes often present with altered vital signs, visual hallucinations, and severe cognitive impairment, including confusion or disorientation.
The assessment of psychosis includes a physical examination, a complete psychiatric and medical history, and a laboratory work-up. The physical examination includes a detailed neurological examination and a complete mental status examination, with the following areas of focus: mood and affect, thought process and content (including an assessment of delusions, abnormal perceptions, suicidal and homicidal ideation, judgement, insight), and a cognitive examination.
The medical history should include a review of head injury, seizures, cerebrovascular disease, sexually transmitted infections, and new or worsening headaches. Collateral history from relatives is recommended to chart the onset and course of psychosis.
Recommended initial laboratory work-up includes a complete blood count, comprehensive metabolic profile, thyroid function tests, urine toxicology, and measurement of parathyroid hormone, calcium, vitamin B12, folate, and niacin.Based on clinical suspicion, testing for HIV infection and syphilis, as well as computed tomography brain imaging, can complete the initial laboratory work-up.
The lifetime prevalence of psychosis in the general population is about 3%, with 0.21% of cases attributable to medical conditions. Most commonly, psychotic symptoms are associated with other mental disorders. The lifetime prevalence of schizophrenia is approximately 0.3%–0.7%. In one urban primary care population study, 20.9% of adult patients reported 1 or more psychotic symptoms; psychosis co-occurred with depressive, anxiety, and panic disorders, and substance use disorders. More than 50% of people with bipolar disorder experience psychosis during their lifetime. The rate of postpartum psychosis, which is a type of brief psychotic disorder, is 1-2 per 1000 childbirths; risk factors include a history of depression, bipolar disorder, or past peripartum psychosis or mood disorder.
Professor of Clinical Psychiatry
Department of Psychiatry and Human Behavior
University of California, Irvine School of Medicine
AP declares that he has no competing interests.
Dr Adrian Preda would like to gratefully acknowledge Dr Karen A. Graham and Dr Diana O. Perkins, previous contributors to this topic. KAG declares that she has no competing interests. DOP has served as a consultant on antipsychotic medications for Genetech, Janssen, Lundbeck, Otsuka, and Sunovion. The University of North Carolina at Chapel Hill received compensation for research and consulting work by DOP from Genetech, the NIH, Research Triangle Institute, and the State of North Carolina; the university has also been awarded a patent for isolation of pluripotent stem cells from human tissues, with Diana Perkins listed as one of the inventors. DOP has received royalties for the textbook Schizophrenia, published by the American Psychiatric Association Press.
Department of Psychiatry
Institute of Psychiatry
PM has been reimbursed by manufacturers of antipsychotic drugs for consultancy and speaking at conferences. PM has received grant funding for research and to support scientific conferences.
Assistant Professor of Psychiatry
Yale University School of Medicine
Connecticut Mental Health Center
VHS declares that he has no competing interests.
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