Undifferentiated schizophrenia is a subtype of schizophrenia. Symptoms may include signs of psychosis, such as delusions and hallucinations, or drastic changes in behavior, speech, or mobility.

However, the current Diagnostic and Statistical Manual of Mental Disorders (DSM) does not list it as a separate diagnosis.

Schizophrenia is a serious mental health condition that usually interferes with a person’s ability to function. Previous versions of the DSM included subtypes of schizophrenia that doctors no longer use as diagnostic criteria.

Doctors may previously have diagnosed undifferentiated schizophrenia if a person experienced psychotic symptoms — such as delusions, hallucinations, and disorganized thinking or behavior — but did not meet the criteria for other subtypes of schizophrenia.

This article discusses undifferentiated schizophrenia in more detail, including its causes, symptoms, diagnosis, and treatment. It also looks at some similar conditions.

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Schizophrenia is a very serious type of mental condition that drastically, and usually negatively, impairs a range of abilities, including:

  • thinking clearly
  • perceiving reality, including changes in smell, taste, touch, hearing, or vision
  • interacting with the outside environment and others
  • managing and expressing emotions and responding appropriately to them
  • processing information to make decisions
  • using motor reflexes
  • remembering, concentrating, and paying attention
  • following a logical chain of thoughts when speaking
  • communicating effectively

About 1% of people in the United States have schizophrenia. However, diagnosing the condition poses challenges, so the actual prevalence may be higher.

The previous edition of the DSM, the DSM-4, contained five subtypes of schizophrenia that the authors classified according to the type of psychotic symptoms they produce. In addition to undifferentiated schizophrenia, the listed subtypes were:

  • Paranoid type: A person with this subtype experiences common auditory hallucinations or delusions but does not experience disorganized behavior or speech, catatonic (inability to move) behavior, a flat emotional state, or out-of-context emotional responses or reactions.
  • Disorganized type: The hallmarks of this type are disorganized behavior and speech, out-of-context emotional reactions or responses, and a flat emotional state.
  • Catatonic type: A person may have this subtype if they experience two or more pervasive changes in motor activity, meaning how they move.
  • Residual type: Those with this subtype have had an episode of schizophrenia but no longer experience psychosis.

The DSM-4 used undifferentiated schizophrenia as the term for cases in which someone experiences psychotic symptoms but does not meet the criteria for other subtypes of schizophrenia. The DSM-5, the current edition, does not contain subtypes of schizophrenia, so the term undifferentiated schizophrenia is no longer in use.

The reasons behind removing the subtypes include:

  • The subtypes did not reflect the variety of ways in which the condition can present.
  • They did not inform treatment approaches or predict the course of the condition.
  • Some people did not continue to meet the criteria of their subtype over time.
  • Some people’s symptoms did not fit any of the subtypes.

Learn more about the former types of schizophrenia here.

Researchers think that various factors combine to cause schizophrenia. These include:

  • Genetics: A mix of genetic changes can interact with environmental factors and other risk factors. About 10% of people with a parent or sibling with schizophrenia develop the condition.
  • Brain chemistry, function, and structure: These include differences in how regions of the brain connect and act together, other changes to networks of neurons, and problems with brain chemicals, such as the neurotransmitters glutamate and dopamine.
  • Environment: Examples include exposure to malnutrition or viruses while in the womb, living in poverty, having stressful surroundings, or having an autoimmune condition.
  • Substance use: For instance, using mind-altering drugs or marijuana, especially frequently and as a teenager or young adult.

Everyone experiences mental health conditions and their symptoms differently. However, in many cases, the symptoms of schizophrenia can be severe, persistent, and disabling.

Common symptoms of schizophrenia include:

  • delusions, such as ideas of being under the control of external forces, facing a threat, or being important to a conspiracy
  • disorganized thinking, including having trouble remembering things, completing tasks, or organizing thoughts
  • hallucinations, such as hearing voices, seeing things, or smelling things that are not there or that others cannot perceive
  • reduced expression of emotions or being emotionally numb or flat
  • speaking in a disconnected, dull, or flat way
  • being unaware of illness or denying it, known as anosognosia
  • illogical or distorted speech or failure to use language effectively
  • social withdrawal
  • self-neglect
  • reduced initiative and motivation
  • motor skill impairment

The symptoms of schizophrenia can develop at any age in anyone, but most people start experiencing symptoms before the age of 40 years. The condition typically presents in males between their late teens and early 20s and in females in their 20s or 30s.

However, subtle behavioral or cognitive changes may develop before — often years before — a person receives a diagnosis of schizophrenia.

Learn more about paranoia and schizophrenia here.

Although schizophrenia can develop at almost any age, the majority of people are aged 12–40 years when they receive a diagnosis.

To diagnose schizophrenia, a doctor may run a series of blood, urine, or imaging tests to rule out other conditions. They will only diagnose the condition if someone has experienced reduced functioning due to at least two of the following symptoms for 6 months or more:

  • hallucinations
  • delusions
  • disorganized speech
  • so-called negative symptoms, such as a reduced ability to express emotions, social withdrawal, and reduced hygiene and self-care
  • extremely disorganized or catatonic behavior

There is no cure for schizophrenia. However, with medication, family support, and psychosocial rehabilitation therapies, many people can reduce and manage their symptoms.

Common treatment options for schizophrenia include:

Antipsychotic medications

These medications target and reduce symptoms of psychosis, including hallucinations and delusions. People can take them daily in the form of a liquid or pill or receive injections a few times a month.

Many people experience negative side effects from taking antipsychotic medications, such as drowsiness, weight gain, and dry mouth. Although these side effects may reduce over time, they can sometimes persist.

However, people should never stop taking antipsychotics suddenly or change their dosage without the advice of a doctor, as this can worsen schizophrenia symptoms or cause other dangerous side effects.

Family education and support

Many resources and services exist to help educate family members, friends, employers, and significant others of people with schizophrenia about the condition. This education often involves learning more about the symptoms, treatment options, and coping mechanisms, as well as strategies to help someone.

Psychosocial treatment

Various services or types of therapy can help people with schizophrenia reduce their cognitive symptoms and the negative symptoms, such as social withdrawal, impaired function, or reduced self-care. They may also help people cope with everyday challenges to allow them to go to school, obtain and keep a job, or maintain healthy relationships.

Options include:

Coordinated special care

This term describes a recovery-oriented treatment program designed for people in an early stage of schizophrenia. It usually involves care and treatment by a team of healthcare professionals. It also seems to improve quality of life, reduce symptoms, and increase function in school or work compared with conventional treatments for early psychosis.

It is important to seek treatment for schizophrenia as soon as symptoms develop. Early detection and treatment can usually reduce the severity of the symptoms that someone experiences.

Schizophrenia has several related conditions, including:

A range of other conditions and factors can also cause psychosis, including:

Learn more about psychosis here.

Undifferentiated schizophrenia is an outdated term describing a subtype of schizophrenia that the medical community no longer recognizes.

People who are experiencing signs of psychosis, such as delusions, hallucinations, or drastic changes in behavior, speech, or mobility, should talk with a mental health professional.

Early diagnosis and effective treatment typically reduce the severity of the symptoms that a person experiences.