Schizophrenia and related disorders exist on a spectrum, meaning they feature a wide range of symptoms that can change over time.

Schizophrenia was once broken down into five subtypes, but today, insights have led us to a new way of seeing schizophrenia as a spectrum.

Schizophrenia is a type of psychotic disorder, and when many people hear the term “psychosis,” they think of schizophrenia exclusively. But people can have episodes of psychosis in a variety of contexts and conditions.

For instance, some people can develop psychosis after using certain substances, going through extreme stress, or during a mood episode in bipolar disorder.

As researchers continue learning more about psychosis and the spectrum of schizophrenia, changes are being made in how it’s diagnosed and treated.

Schizophrenia is a complex mental health condition that affects an estimated 24 million people or 1 in 300 people worldwide. When the condition is active, it can affect a person’s thoughts, behaviors, and perception of reality.

Before the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) was published in 2013, older guidance divided schizophrenia into five subtypes:

So prior to 2013, depending on your symptoms you may have been diagnosed with a specific type of schizophrenia, such as paranoid schizophrenia.

These subtypes are no longer used in the DSM-5. Today, the diagnosis would just be schizophrenia.

The American Psychiatric Association determined that the subtypes were not helpful to clinicians because schizophrenia symptoms often overlap and may even change over time from one type to another.

But some people may still identify with certain subtypes and some clinicians still use aspects of previous subtypes to help determine a diagnosis or treatment plan.

For instance, features of catatonia or paranoia in someone with schizophrenia are now added as specifiers to a schizophrenia diagnosis (e.g., schizophrenia with catatonia).

In the DSM-5, schizophrenia is now under the disorder class “Schizophrenia Spectrum and Other Psychotic Disorders.” This replaced the DSM-4’s class “Schizophrenia and Other Disorders.”

The term “spectrum” better describes how people with schizophrenia tend to have a wide range of symptoms that can change over time. Also, every person with schizophrenia has a unique experience of the condition with varying degrees of how severe their symptoms are.

Other psychotic disorders

There are several conditions that fall under the disorder class “Schizophrenia Spectrum and Other Psychotic Disorders.”

This includes:

  • Schizophrenia. Schizophrenia is characterized by symptoms that affect a person’s thoughts, behaviors, and ability to interpret reality. These symptoms must last for more than 6 months.
  • Schizoaffective disorder. This condition involves a combination of schizophrenia symptoms (typically delusions and hallucinations) and mood disorder symptoms (such as mania or depression).
  • Schizophreniform disorder. Someone with this condition has symptoms of schizophrenia that last between 1 and 6 months.
  • Brief psychotic disorder. Brief psychotic disorder is a condition where someone has a short-term episode of psychosis brought on by extreme stress. Symptoms last for at least 1 day but less than 1 month.
  • Delusional disorder. People with this disorder have delusions that last for at least 1 month without other schizophrenia symptoms. Symptoms can’t be explained by any other condition.
  • Substance/medication-induced psychotic disorder. In this case, symptoms of psychosis are brought on by medications or substance use.
  • Psychotic disorder due to another medical condition. Someone may be diagnosed with this condition if their symptoms are triggered by a medical illness or traumatic brain injury.

Schizotypal personality disorder is also briefly mentioned under this disorder class in the DSM-5. But it’s now categorized as a personality disorder and involves odd speech or thinking patterns, unusual beliefs, and paranoia.

According to research from 2014, the relatives of individuals with schizophrenia may have a greater chance of developing:

Before the onset of schizophrenia (when schizophrenia symptoms begin), many people experience prodromal symptoms. These symptoms are often mistaken for depression or other mood disorders.

Prodromal symptoms are considered the first “phase” of schizophrenia and may include:

  • withdrawal from social activities
  • angry outbursts
  • a decrease in hygiene habits
  • loss of interest in work or school
  • unusual behavior

After the prodromal phase, the active symptoms of schizophrenia will appear. Schizophrenia’s onset tends to differ by sex.

According to the National Institute of Mental Health, males tend to start having symptoms between their late teens to mid-20s. In females, symptoms begin in their 20s to 30s.

Schizophrenia symptoms are often divided into:

Positive symptoms

Positive symptoms are any that “add” to a person’s personality. In other words, these are symptoms that weren’t there before (they’re not positive as in “good”).

Positive symptoms include the most well-known symptoms of psychosis, such as:

  • delusions
  • hallucinations
  • disorganized thoughts and speech
  • disorganized motor behavior (such as catatonia or unpredictable agitation)

Negative symptoms

Negative symptoms are those that “take away” from a person’s personality. This can include:

  • a lack of emotional expression (flat affect)
  • less interest in self-motivated activities (avolition)
  • less ability to experience pleasure (anhedonia)
  • talking less (alogia)

Cognitive symptoms

Cognitive symptoms may affect a person’s:

  • working memory
  • executive functioning
  • focus and attention span

Symptom dimensions

After the DSM-5 removed subtypes, clinicians now typically focus on symptom dimensions and their severity. Symptom dimensions are broader types or categories of symptoms.

For schizophrenia, symptom dimensions include:

  • reality distortion (e.g., delusions or hallucinations)
  • disorganization
  • negative symptoms
  • cognitive impairment
  • motor symptoms
  • mood symptoms

According to the DSM-5 diagnostic criteria, you can be diagnosed with schizophrenia if you have at least two of the following symptoms:

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

One of these symptoms must be one of the first three symptoms: delusions, hallucinations, or disorganized thoughts and speech.

These symptoms must occur often for at least 1 month, while the effects of your symptoms have lasted at least 6 months total.

In addition, your condition has made it harder (or near-impossible) to function in one or more areas of your life, including:

  • work
  • personal relationships
  • taking care of yourself

Many people with schizophrenia are not aware of their symptoms or condition at first.

Conditions that look like schizophrenia

Several psychiatric and medical conditions share similar features with schizophrenia. This is why doctors need to do a careful evaluation of someone’s symptoms to tell the difference between similar-looking conditions.

Conditions that may sometimes look like schizophrenia include any of the disorders in the “Schizophrenia Spectrum and Other Psychotic Disorders” class (listed above), as well as the following conditions:

  • Post-traumatic stress disorder (PTSD). With PTSD, there is often a traumatic event that brings on symptoms. It also usually involves anxiety and reliving or reacting to the event or trigger.
  • Obsessive-compulsive disorder (OCD). A primary difference is that OCD involves prominent obsessions and compulsions.
  • Major depressive or bipolar disorder with psychotic or catatonic features. Some people with mood disorders like major depressive disorder or bipolar disorder have periods of psychosis or catatonia.
  • Thyroid disorder. Thyroid conditions mimic some mental health conditions but also typically have physical symptoms like coarse hair and skin, protruding eyeballs, a goiter (an irregular growth of the thyroid gland), a high or low heart rate, and tremors.
  • Autism spectrum disorder (ASD). Autistic people usually experience challenges with their social skills and repetitive or restricted behavior.
  • Major neurocognitive disorder (aka dementia). Dementia symptoms include issues with cognition and memory but the average age of onset is age 83.
  • Brain tumor. Depending on the location of the brain tumor, symptoms may be similar, but lesions would be detected on CT or MRI scans of the brain.
  • Cushing syndrome. This condition occurs when your body has too much cortisol. Some external symptoms may include muscle weakness (difficulty getting out of chairs), abdominal stretch marks, and a fatty hump between the shoulders.

Schizophrenia is considered a spectrum with a variety of features and levels of severity.

While schizophrenia used to have subtypes, these were retired because schizophrenia symptoms often overlap and change over time.

Schizophrenia isn’t the only condition that includes episodes of psychosis or similar symptoms. This is why it’s important for healthcare professionals to carefully observe someone’s symptoms to determine an accurate diagnosis.

As our understanding of psychotic disorders improves, experts will update guidance for the best diagnosis and treatment plans.

If you want to learn more about living with schizophrenia and treatments, you can find helpful articles at Psych Central’s schizophrenia hub.