To diagnose schizophrenia, one has first to rule out any medical illness that may be the actual cause of the behavioral changes. Once medical causes have been looked for and not found, a psychotic illness such as schizophrenia could be considered. The diagnosis will best be made by a licensed mental health professional (preferably a psychiatrist) who can evaluate the patient and carefully sort through a variety of mental illnesses that might look alike at the initial examination.

The doctor will examine someone in whom schizophrenia is suspected either in an office or in the emergency department. The doctor's role is to ensure that the patient doesn't have any medical problems. The doctor takes the patient's history and performs a physical examination. Laboratory and other tests, sometimes including a computerized tomography (CT) scan of the brain, are performed. Physical findings can relate to the symptoms associated with schizophrenia or to the medications the person may be taking.

People with schizophrenia can exhibit a mild confusion or clumsiness.

Subtle minor physical features, such as highly arched palate or wide or narrow set eyes, have been described, but none of these findings alone allow the physician to make the diagnosis.

Most symptoms found are related to movement (motor symptoms). Some of these can be side effects of prescribed medications. Medications may, for example, cause dry mouth, constipation, drowsiness, stiffness on one side of the neck or jaw, restlessness, tremors of the hands and feet, and slurred speech.

Tardive dyskinesia is one of the most serious side effects of medications used to treat schizophrenia. It is usually seen in older people and involves facial twitching, jerking and twisting of the limbs or trunk of the body, or both. It is a less common side effect with the newer generation of medications used to treat schizophrenia. It does not always go away, even when the medicine that caused it is discontinued.

A rare, but life-threatening complication resulting from the use of neuroleptic (antipsychotic, tranquilizing) medications is neuroleptic malignant syndrome (NMS). It involves extreme muscle rigidity, sweatiness, salivation, and fever. If this is suspected, it should be treated as an emergency.

Generally, results are normal in schizophrenia for the lab tests and imaging studies available to most doctors. If the person has a particular behavior as part of their mental disorder, such as drinking too much water, then this might show as a metabolic abnormality in the person's laboratory results. Some medications can trigger a decreased immune response, reflected by a low number of white blood cells in the blood. Likewise, in people with NMS, metabolism may be abnormal.

Family members or friends of the person with schizophrenia can help by giving the doctor a detailed history and information about the patient, including behavioral changes, previous level of social functioning, history of mental illness in the family, past medical and psychiatric problems, medications, and allergies (to foods and medications), as well as the person's previous physicians and psychiatrists. A history of hospitalizations is also helpful so that old records at these facilities might be obtained and reviewed.

WebMD Medical Reference from eMedicineHealth

Reviewed by Amal Chakraburtty, MD on February 01, 2007