Psychosis is a syndrome associated with dysregulation of the neurotransmitters dopamine and serotonin, and abnormal functioning of key brain circuits, particularly involving frontal, temporal, and mesostriatal brain regions.[1] People with psychosis typically experience hallucinations (e.g., auditory, visual, tactile), delusions, and disorganized thoughts and actions.
Psychosis can be due to primary ('non-organic') psychiatric disorders or can be secondary to substance use or specific medical ('organic') etiologies.[2] 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.[3] Patients with psychosis associated with psychiatric disorders present with a combination of hallucinations (mostly auditory), delusions, and disorganized 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 evaluation of psychosis includes a physical exam, a complete psychiatric and medical history, and a laboratory work-up. The physical exam should include a detailed neurologic exam and a complete mental status exam, with the following areas of focus: mood and affect, thought process and content (including an evaluation of delusions, abnormal perceptions, suicidal and homicidal ideation, and insight), and a cognitive exam.
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 the 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.[4] [5] Based on clinical suspicion, testing for HIV infection and hepatitis C, as well as brain neuroimaging (e.g., CT or MRI), should be considered as part of the initial work-up.[4] [5] [6]
