Schizophrenia Spectrum Disorder: Symptoms and Related Conditions

Psychotic disorders exist on a spectrum. Symptoms may be shared but can vary in different ways, including intensity.

A person’s treatment and outlook will depend on the specific diagnosis, so getting an accurate diagnosis is important.


In the “Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV),” a reference handbook for mental health care professionals, there were many subtypes of schizophrenia, each with its own range of symptoms. These subtypes included:

  • paranoid
  • hebephrenic or disorganized
  • catatonic
  • undifferentiated
  • residual

The 5th edition of the DSM (DSM-5) no longer uses these subtypes. However, it does recognize that schizophrenia can present in different ways. It’s important to remember the wide variety of symptoms.

For a doctor to diagnose schizophrenia, you would have to show at least two of the following symptoms over a period of 6 months:

  • delusions
  • hallucinations
  • disorganized speech
  • disorganized behavior or catatonic behavior
  • negative symptoms

At least one of these symptoms needs to be delusions, hallucinations, or disorganized speech to get a diagnosis.

Schizophrenia symptoms also cause problems with day-to-day life. They affect the ability to work, interact with others, and take care of yourself.

If symptoms don’t meet these criteria, a doctor may diagnose a related spectrum disorder instead.

Schizophreniform disorder

Schizophreniform disorder is very similar to schizophrenia, but symptoms last for 1 to 6 months. If the symptoms last longer than 6 months, a doctor may diagnose schizophrenia.

You don’t need to have problems functioning to receive a diagnosis of schizophreniform disorder.

Schizoaffective disorder

In schizoaffective disorder, people have symptoms of schizophrenia with a major mood disorder, like depression or bipolar disorder. Delusions or hallucinations need to be present for at least 2 weeks before the mood disorder symptoms begin.

Schizoaffective disorder is about one-third as common as schizophrenia.

Delusional disorder

As its name implies, delusional order involves someone having delusional beliefs for at least 1 month.

These delusions could be “bizarre,” meaning they’re about things that cannot happen in real life. But they could also be non-bizarre, which means they are things that could happen, like being followed or having a disease.

Functioning and behavior are not impaired. However, these beliefs can cause problems within relationships, school, or work.

Schizotypal personality disorder

The symptoms of schizotypal personality disorder can look like schizophrenia but are less intense and not as intrusive. Symptoms can include:

  • being distant or introverted
  • having an intense fear of intimacy or closeness
  • disordered thinking and perception
  • ineffective communication skills

Brief psychotic disorder

A doctor may diagnose brief psychotic disorder if you have a short episode of psychosis lasting between 1 day and 1 month. After that time, the symptoms completely disappear. A person will have one or more of these symptoms:

  • delusions
  • hallucinations
  • disorganized speech
  • very disorganized behavior

Shared psychotic disorder

Shared psychotic disorder, also called folie à deux, was removed from the DSM-5. But it’s being listed here because it has been in the clinical environment for a long time.

This rare disorder occurs when two or more people in a fairly close relationship share a delusion. One person with delusions influences the other person based on the false belief.

While typically seen in groups of two, it can affect larger groups too.

Psychotic disorder from a general medical condition

In this disorder, symptoms of psychosis occur concurrently with a chronic or temporary illness. The symptoms are not from use or withdrawal of a substance and happen outside of delirium.

Doctors think this happens due to changes in brain functioning during an illness, such as:

  • stroke
  • autoimmune disease
  • thyroid disease
  • epilepsy
  • multiple sclerosis

Your treatment will depend on the underlying health condition. Treating the condition usually stops the symptoms.

Substance-induced psychotic disorder

If symptoms of psychosis are from medications, recreational drugs, or alcohol, this may be substance-induced psychotic disorder.

People with a diagnosed mental health disorder or with a predisposition to psychosis are at higher risk of this if they misuse substances or experience withdrawal from substances.

Symptoms include:

  • hallucinations or delusions
  • unusual or suspicious beliefs
  • delusions of persecution
  • reduced emotional expression
  • aggressive behavior
  • poor thinking
  • lack of speech