How Schizophrenia Is Officially Diagnosed

Medically reviewed by Michael MacIntyre, MD

Schizophrenia is officially diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic manual. There isn't a single schizophrenia test or biomarker in the blood that can diagnose this chronic brain disorder.

Schizophrenia affects less than 1 in 100 people. In the United States, it's estimated that the prevalence of schizophrenia and other related psychotic disorders is between 0.24% and 0.64%.

Getting an official schizophrenia diagnosis doesn't happen "accidentally," but sometimes a person who's having hallucinations or delusions will be hospitalized for psychiatric evaluation and receive an official diagnosis after other mental health disorders or medical conditions have been ruled out.

This article explains what you need to know about the diagnostic criteria for schizophrenia and walks you through the journey of getting an official diagnosis from the patient's point of view.

Getting Schizophrenia Diagnosed: DSM-5 Criteria

The DSM-5 was published in 2013. In this edition, for the first time, schizophrenia is classified as a spectrum of conditions under the umbrella term "schizophrenia spectrum disorders (SSDs)".

The following are characteristic symptoms of schizophrenia:

• Delusions (false beliefs)

• Hallucinations (seeing things that aren't there)

• Disorganized speech

• Grossly disorganized or abnormal motor behavior

• Negative symptoms (i.e., flat affect, reduced speech, avolition)

What Are Schizophrenia Spectrum Disorders?

Schizoaffective disorder, schizophreniform disorder, brief psychotic disorder, and delusional disorder are all categorized under the umbrella of schizophrenia spectrum disorders (SSDs).

Schizophrenia Diagnosis During Hospitalization

As schizophrenia progresses and someone first experiences psychosis marked by having difficulty discerning what's real and what's not real or having auditory hallucinations, they may be admitted to a hospital for evaluation.

During this initial hospital visit, a series of psychological and physical tests are conducted to rule out other diseases or substance use disorders and, if needed, begin the official schizophrenia diagnostic process, which can take a few months.

Related: What Are the Different Types of Schizophrenia?

Tests Used to Reach a Schizophrenia Diagnosis

When someone first starts having schizophrenia-like symptoms, it's impossible to know what's causing them until tests are run to rule out other issues like a brain tumor, encephalitis, epilepsy, or autoimmune diseases that affect the central nervous system.

To reach a schizophrenia diagnosis, the first step is to conduct a physical exam, do some blood tests, and undergo neuroimaging tests like an magnetic resonance imaging (MRI) scan or a computed tomography (CT) scan. All of these tests can diagnose medical conditions other than schizophrenia that might be causing symptoms of psychosis. Because there isn't a single test for schizophrenia, arriving at a diagnosis requires a process of elimination.

In general, lab results and brain imaging test results don't show any red flags and appear normal in people with schizophrenia. If lab tests and brain scans don't detect another potential cause for someone's schizophrenia-like symptoms, the next step is to assess them based on DSM-5 criteria for diagnosing schizophrenia spectrum disorders.

Odds of Misdiagnosis

People experiencing schizophrenia-like symptoms may receive the wrong diagnosis or multiple potentially inaccurate diagnoses in the early stages of their diagnostic process. A 2019 study conducted by the Johns Hopkins Early Psychosis Intervention Clinic (EPIC) found that among 78 patients, about half of them were initially misdiagnosed.

Because schizophrenia doesn't progress linearly and the odds of misdiagnosis are high, it's always wise to get a second opinion from a specialty clinic if possible.

Risks of Delayed Schizophrenia Diagnosis

Seeking treatment within the first few days or weeks of psychosis onset can dramatically improve outcomes for people who are ultimately officially diagnosed with schizophrenia. A 2020 longitudinal analysis on the effects of delaying treatment after schizophrenia-like symptoms appear can increase the risk of harmful symptoms progressing quickly and potentially becoming treatment-resistant. 

How Do You Know If You Have Schizophrenia?

Because the hallmark symptoms of schizophrenia—hallucinations and delusions—interfere with thinking clearly, you may have difficulty acknowledging you have a problem like schizophrenia. Similarly, self-testing for psychotic disorders like schizophrenia isn't the best option because it's almost impossible to be objective about your mental health if you're having delusions or hallucinations.

If you or someone you know is having schizophrenia-like symptoms, speak with a healthcare provider who can perform an initial assessment and refer you to the appropriate mental health professional, such as a psychiatrist or clinical psychologist. In crisis situations, call or text 988 to speak with a trained mental health counselor at the 988 Suicide & Crisis Lifeline, or go to a nearby emergency room.

Summary

The diagnosis criteria for schizophrenia published in the DSM-5 includes five main symptoms: delusions, hallucinations, disorganized speech, disorganized behavior, and negative symptoms like not expressing emotions (flat affect). Lab tests can't diagnose schizophrenia, but during the diagnostic process, lots of different tests are done to rule out other illnesses.

If you or someone you know has symptoms of schizophrenia, start by talking to a healthcare provider who can refer you to a mental health professional like a psychiatrist or clinical psychologist.

Read the original article on Verywell Health.