Diagnosis relies on careful examination, exhaustive history taking, and close observation by a qualified psychiatrist.


The physician will interview family members or close associates, gathering information about the patient’s condition and history, including the following:

  • when symptoms first appeared
  • if there is a family history of the disease
  • how the patient’s ability to function has changed
  • how he or she progressed through the various stages of childhood development
  • how he or she has responded to any medications that may have been prescribed

During the interview, any supplements or medications the patient is currently taking should be discussed.

Diagnosis may also involve assessing and identifying any concomitant health issues that may impact a patient’s prognosis. Examples include chemical dependence, substance abuse, dietary insufficiencies, or pre-existing health conditions, such as pre-diabetes, hypertension, or an abnormal blood lipid profile.

Diagnostic Criteria Revisions

Psychiatrists diagnose schizophrenia in accordance with specific diagnostic criteria established by the American Psychiatric Association (APA). These guidelines are published in the APA’s Diagnostic and Statistical Manual of Mental Disorders (DSM). The most current version of the guidelines, DSM-IV, was last revised in 2000. It is due for a major revision, many years in the making, in early 2013. That new version, DSM-5, proposes several changes regarding the diagnosis of schizophrenic disorders (APA members recently decided to drop the Roman numeral system when designating DSM revisions). Tentative changes include dropping certain obsolete diagnostic labels, such as paranoid schizophrenia, catatonic schizophrenia, and undifferentiated schizophrenia, among others.