What are the traditional types of schizophrenia?
For many decades, in the 10th international classification (ICD-10) and in earlier editions of the American manual, schizophrenia was divided into types according to the predominant symptom. These names are still widespread among the public and in some older medical reports:
| Old type | Predominant feature |
|---|---|
| Paranoid schizophrenia | Persecutory or grandiose delusions and auditory hallucinations, with relatively preserved speech and behavior. |
| Disorganized (hebephrenic) schizophrenia | Disorganized speech and behavior and emotions that do not fit the situation, often starting early. |
| Catatonic schizophrenia | Prominent movement disturbances: rigidity, silence, repetitive movements, or resistance to any movement. |
| Undifferentiated schizophrenia | Schizophrenia symptoms that do not fit any one type. |
| Residual schizophrenia | Mild or negative symptoms that remain after the acute episode has ended. |
| Simple schizophrenia | Gradual decline in functioning and negative symptoms without clear hallucinations or delusions; it existed in ICD-10 only. |
Why were the schizophrenia types removed from modern classifications?
When scientific committees reviewed these types, they found three problems. First, the type in the same patient changed from one episode to the next, so someone who began “paranoid” might become “undifferentiated” after some years. Second, doctors often disagreed about the type for the same patient. Third, and most important, the type did not change the treatment plan or predict the course accurately.
That is why the American Diagnostic and Statistical Manual (DSM-5) removed the subtypes in 2013, followed by the International Classification of Diseases (ICD-11) endorsed by the World Health Organization. Instead, the doctor describes the severity of each group of symptoms and the course of the illness, a more precise and more useful way to follow a patient.
How is schizophrenia described today in ICD-11 and DSM-5?
ICD-11 uses two kinds of specifiers. The first is symptom specifiers, in which the doctor rates the severity of six domains: positive, negative, depressive, manic, psychomotor, and cognitive symptoms. The second is course specifiers:
When the person is going through a first episode that meets the criteria for schizophrenia, noting whether he or she currently has symptoms or is in partial or full remission.
When episodes recur with clear periods of remission between them.
When symptoms are present for most of the illness without notable periods of remission.
ICD-11 requires the core symptoms to last at least one month to diagnose schizophrenia, while DSM-5 requires continuous signs of the disorder for at least six months, including one month of active symptoms. DSM-5 also allows catatonia to be specified as a separate specifier rather than treated as a type.
What disorders are related to schizophrenia?
Modern classifications group schizophrenia with other disorders that share psychotic symptoms under what is called the schizophrenia spectrum and other psychotic disorders. Telling them apart matters because they differ in course and follow-up:
| Disorder | What distinguishes it | Note |
|---|---|---|
| Schizophrenia | Hallucinations, delusions, or disordered thinking with a decline in functioning | Longer duration than the others, according to the criteria |
| Schizophreniform disorder | The same symptoms as schizophrenia but lasting from one month to less than six months | A diagnosis in DSM-5; it may improve or turn into schizophrenia |
| Brief psychotic disorder | A sudden psychotic episode lasting from one day to less than a month, after which the person returns to their previous state | The ICD-11 equivalent is acute and transient psychotic disorder |
| Schizoaffective affective disorder | Schizophrenia symptoms occurring together with clear depressive or manic episodes | Needs treatment for both psychosis and mood |
| Delusional disorder | One or more fixed delusions, such as jealousy or persecution, with relatively preserved functioning | Few or no hallucinations |
| Schizotypal disorder | Odd ideas and behaviors and limited relationships without outright psychosis | Also counted as a personality disorder in DSM-5 |
What is the difference between schizophrenia and schizoaffective disorder?
In schizoaffective disorder, schizophrenia symptoms occur together with full mood episodes, depression or mania, for most of the illness. It differs from bipolar disorder with psychosis in that psychotic symptoms also appear in periods when there is no mood episode. This distinction is subtle and needs follow-up over time, which is why the diagnosis may change after a while.
What is the difference between schizophrenia and psychosis caused by drugs or physical illness?
Before diagnosing schizophrenia, the doctor must rule out that the symptoms come directly from a substance, a medication, or a physical illness, such as brain infections, epilepsy, or thyroid disorders. Drug-induced psychosis is a separate diagnosis with its own page, and it can sometimes be the start of a course that needs longer follow-up.
Are there special forms of schizophrenia by age or response to treatment?
- Early-onset schizophrenia: when it begins before age 18. It is less common and needs a team specialized in child and adolescent psychiatry.
- Childhood-onset schizophrenia: before age 13. It is very rare and requires careful ruling out of developmental and other disorders.
- Late-onset schizophrenia: after age 40, more common in women, and dominated by delusions.
- Treatment-resistant schizophrenia: a clinical description, not a diagnostic type, for people who have not responded sufficiently to at least two different medications. It has special options explained on the page about schizophrenia treatment.
Does knowing the “type” change anything for the patient?
What really matters to the patient and family are practical questions more than a subtype name: Which symptoms are most troubling now? Is this a first episode or a recurrence? Are there accompanying mood symptoms? Is there any substance use? This is the information the treatment and rehabilitation plan is built on, and it is what the doctor records in modern classifications.