To diagnose schizophrenia, one has first to rule out any medical illness that may be the actual cause of 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 initial role is to ensure that the patient doesn't have any medical problems. Certain neurological disorders (such as epilepsy, brain tumors, and encephalitis), endocrine and metabolic disturbances, infectious diseases, and autoimmune conditions involving the central nervous system can sometimes cause symptoms that look like schizophrenia. The doctor takes the patient's history and performs a physical exam. Laboratory and other tests, sometimes including brain imaging techniques such as a computerized tomography (CT) scan or magnetic resonance imaging (MRI) of the brain, are performed. Physical findings can relate to the symptoms associated with schizophrenia or to medications the person may be taking. Psychological testing can also be used to further explore the symptoms of schizophrenia. These tests can include cognitive testing, personality testing, and open-ended or projective testing such as the Rorschach (inkblot) test.
Psychotic symptoms can be triggered by many drugs, including alcohol, PCP, heroin, amphetamines, cocaine, and some over-the-counter and prescription drugs. A toxicology screen can help determine if any substances in the body could have led to the psychotic symptoms. Sometimes symptoms are seen during intoxication and sometimes during withdrawal. If substance abuse is involved, the doctor can help determine if the drug use is the source of the psychotic symptoms or is simply an additional factor.
A doctor will also complete a psychiatric evaluation in which he or she will ask the patient or the patient’s family or both a series of questions regarding the patient’s symptoms and psychiatric history.
People with schizophrenia can exhibit a mild confusion or clumsiness.
Subtle minor physical features, such as a highly arched palate, wide or narrow set eyes, cuspidal ears (ears with angled ridges instead of a round curve at the top of the opening into the ear canal) or attached ear lobes, or cross-eyes have been described, but none of these findings alone allow a doctor to make the diagnosis.
Additional physiological changes that are sometimes associated with schizophrenia include altered levels of chemicals in the body, insensitivity to pain, and abnormal ability to control body temperature.
Tardive dyskinesia is one of the most serious side effects of medications used to treat schizophrenia. This rare side effect is more common 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 drugs used to treat schizophrenia. It does not always go away, even when the medicine that caused it is discontinued, but it can be treated with deutetrabenazine (Austedo) or valbenazine (Ingrezza)..
A rare, but life-threatening complication resulting from the use of neuroleptic (antipsychotic, tranquilizing) drugs is neuroleptic malignant syndrome (NMS). It involves extreme muscle rigidity, sweatiness, salivation, and fever. If this is suspected, it should be treated as a medical emergency.
Generally, laboratory results and imaging studies available to most doctors are normal in schizophrenia. If the person has a particular behavior as part of a mental disorder, such as drinking too much water, then this might show as a metabolic abnormality in the person's laboratory results. Some drugs 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.