

Patients suffering from psychosis are unable to distinguish the real from the unreal. They experience hallucinations and/or delusions that they believe are real, and they typically behave in an inappropriate and confused manner.

Causes and Symptoms

Psychosis may be caused by a number of biological and social factors, depending on the disorder underlying the symptom. Trauma and stress can induce a short-term psychosis known as brief psychotic disorder. This psychotic episode, which lasts a month or less, can be brought on by the stress of major life-changing events (e.g., death of a close friend or family member, natural disaster, traumatic event), and can occur in patients with no prior history of mental illness.

Causes and Symptoms
Causes and Symptoms

Psychosis can also occur as a result of an organic medical condition (known as psychotic disorder due to a general medical condition). Neurological conditions (e.g., epilepsy, migraines, Parkinson’s disease, cerebrovascular disease, dementia), metabolic imbalances (hypoglycemia), endocrine disorders (hyper- and hypothyroidism), renal disease, electrolyte imbalance, and autoimmune disorders may all trigger psychotic episodes.

Hallucinogenics, PCP, amphetamines, cocaine, marijuana, and alcohol may cause a psychotic reaction during use, abuse, or withdrawal. Certain prescription medications such as anesthetics, anticonvulsants, chemotherapeutic agents, and antiparkinsonian medications may also induce psychotic symptoms as a side-effect. In addition, toxic substances like carbon dioxide and carbon monoxide, which may be deliberately or accidentally ingested, have been reported to cause substance-induced psychotic disorder.

Schizophrenia and its related disorders (schizophreniform disorder and schizoaffective disorder), mental illnesses with strong psychotic features, are thought to be caused by abnormalities in the structure and chemistry of the brain and influenced by both social and genetic factors.

Ngoc Trinh
Delusional disorder

Delusional disorder, another mental illness defined by psychotic episodes, is also thought to have a possible hereditary and neurological base. Abnormalities in the limbic system, the portion of the brain on the inner edge of the cerebral cortex that is believed to regulate emotions, are suspected to cause the delusions that are a feature of psychosis.

Psychosis is characterized by the following symptoms:
  • Disorganized or catatonic behavior. Behavior that is completely inappropriate to the situation or environment. Catatonic patients have either a complete lack of or inappropriate excess of motor activity. They can be completely rigid and unable to move (vegetative), or in constant motion. Disorganized behavior is unpredictable and inappropriate for a situation (e.g., screaming obscenities in the middle of class).


Hitomi Komatani
catatonic behavior

Patients with psychotic symptoms should undergo a thorough physical examination and detailed patient history to rule out organic causes of the psychosis (such as brain tumor). If a psychiatric cause is suspected, a psychologist or psychiatrist will usually conduct an interview with the patient and administer clinical assessments.

These assessments may include the Adolescent Behavior Checklist (ABC), Anxiety Disorders Interview Schedule for DSM-IV (ADIS-IV), Psychotic Behavior Rating Scale (PBRS), and the Chapman Psychosis Proneness Scales.


Psychosis caused by schizophrenia or another mental illness should be treated by a psychiatrist and/or psychologist. Other medical and mental health professionals may be part of the treatment team, depending on the severity of the psychosis and the needs of the patient. Medication and/or psychosocial therapy is typically employed to treat the underlying disorder.

Siva Aprilia
Adolescent Behavior Checklist

Antipsychotic medications commonly prescribed to treat psychosis include risperidone (Risperdal), thioridazine (Mellaril), halperidol (Haldol), chlorpromazine (Thorazine), clozapine (Clozaril), loxapine (Loxitane), molindone hydrochloride (Moban), thiothixene (Navane), and olanzapine (Zyprexa). Possible common sideeffects of antipsychotics include dry mouth, drowsiness, muscle stiffness, and hypotension.

More serious side effects include tardive dyskinesia (involuntary movements of the body) and neuroleptic malignant syndrome (NMS), a potentially fatal condition characterized by muscle rigidity, altered mental status, and irregular pulse and blood pressure.

Once an acute psychotic episode has subsided, psychosocial therapy and living and vocational skills training may be recommended. Drug maintenance treatment is usually prescribed to prevent further episodes.


tardive dyskinesia
tardive dyskinesia

The longer and more severe a psychotic episode, the poorer the prognosis for the patient. However, early diagnosis and long-term follow-up care can improve the outcome for patients with psychotic disorders. Schizophrenia has a 60% treatment success rate.