Psychosis refers to symptoms such as delusions, hallucinations, disorganized thinking and speech, and bizarre and inappropriate motor behavior (including catatonia) that indicate loss of contact with reality.
This diagnosis applies when psychosis is due to the physiologic effects of a medical condition. Examples are psychotic behavior or olfactory hallucinations that are sometimes associated with temporal lobe epilepsy and the contralateral neglect syndrome that is sometimes caused by parietal lobe lesions.
The diagnosis is not used if patients have a psychologically mediated response to medical illness (eg, intensive care unit [ICU] psychosis), psychosis due to the effects of drugs or drug withdrawal, or delirium caused by a medical condition.
It is essential to establish a temporal relationship between the medical and psychotic condition (ie, they begin and end at the same time).
Treating the medical condition often reduces the severity of psychotic symptoms, but some patients also need specific treatment for the psychotic symptoms.