Undifferentiated schizophrenia, a previously recognized subtype, describes symptoms that don’t fit into a specific subtype.

Schizophrenia is a complex psychiatric disorder characterized by a breakdown in the relationship between thoughts, emotions, and behaviors. Symptoms may include hallucinations, delusions, and cognitive difficulties.

Until 2013, schizophrenia was divided into five subtypes, one of which was called “undifferentiated schizophrenia.”

If you were diagnosed with this subtype, it meant that you met the criteria for a schizophrenia diagnosis but didn’t fit neatly into a specific subtype.

Undifferentiated schizophrenia is a classic subtype of schizophrenia that’s no longer recognized in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision (DSM-5-TR).

When a person was diagnosed with undifferentiated schizophrenia, it meant they were exhibiting symptoms of the disorder (like hallucinations, delusions, or disorganized speech), but they didn’t meet the full criteria for one of the schizophrenia subtypes (e.g., paranoid, catatonic, or disorganized).

Research from 1991 suggests that people who were diagnosed with undifferentiated schizophrenia tended to have an early history of behavioral difficulties. The disorder was often continuous and stable (rather than on-and-off symptoms).

Undifferentiated schizophrenia was a term previously used in the DSM-3 and DSM-4 to describe a person who didn’t meet the criteria for other subtypes of schizophrenia.

But since subtypes are no longer used in the DSM-5, there’s no reason to use the term.

Why are there no longer schizophrenia subtypes in the DSM-5?

In the DSM-3 and the DSM-4, schizophrenia was divided into 5 subtypes.

  • Paranoid type: A person with paranoid schizophrenia will have predominantly positive symptoms of schizophrenia, like delusions and hallucinations. But they’ll be less likely to have catatonia (inability to move), a flat emotional state, or out-of-context emotional reactions.
  • Disorganized type: Also known as hebephrenic schizophrenia, is characterized by disorganized behavior and speech and involves disturbances in emotional expression (out-of-context emotional reactions or flat emotional state). Hallucinations and delusions are non-existent or much less severe in this type.
  • Catatonic type: This type involves severe psychomotor disturbances, like being unresponsive to the environment even when awake.
  • Residual type: A person with this subtype has had at least one episode of schizophrenia but no longer experiences significant positive symptoms (hallucinations, delusions) or disorganized speech or behavior.
  • Undifferentiated type: A person with this subtype meets the criteria for a schizophrenia diagnosis but cannot be classified into any of the subtypes.

These subtypes were removed in the DSM-5-TR (formerly known as DSM-5), which was first published in 2013 and updated in 2022. The American Psychiatric Association determined that the subtype model didn’t fully capture the complexity of the disorder, especially since subtype features tend to overlap and change over time.

In the DSM-5, schizophrenia is now referred to as a spectrum disorder.

With the removal of subtypes, clinicians now focus on a variety of symptom dimensions and their severity.

Schizophrenia symptom dimensions include the following:

  • reality distortion (delusions, hallucinations)
  • negative symptoms
  • disorganization
  • motor symptoms
  • mood symptoms
  • cognitive impairment

Subtype symptoms may also be used to help clinicians determine a diagnosis and treatment plan. For instance, if you present with features of paranoia or catatonia, those terms would now be added as specifiers to your schizophrenia diagnosis.

Due to an increased understanding of the disorder, researchers now see schizophrenia as a spectrum disorder rather than a single disorder broken into subtypes.

In the DSM-5-TR, the diagnosis of schizophrenia is known as “Schizophrenia Spectrum and Other Psychotic Disorders.” It was known as “Schizophrenia and Other Psychotic Disorders” in DSM-4.

The term “spectrum” better describes the disorder’s complexity, especially since symptoms in these subtypes tend to overlap and change over time. For instance, you may have paranoid symptoms in the beginning of the illness and then develop more disorganized symptoms later on.

With the spectrum approach, the diagnostic criteria can be more flexible, allowing for greater variety and understanding that people with the disorder may not fit neatly into one subtype.

Undifferentiated schizophrenia is a subtype of schizophrenia that’s no longer used in the DSM-5-TR.

When a person was given this diagnosis, it meant they were showing schizophrenia symptoms but didn’t meet the full criteria for one of the subtypes of schizophrenia.

If you think you’re experiencing symptoms of schizophrenia, consider reaching out to a mental health clinician to receive a professional diagnosis.