Schizophrenia is a chronic neurocognitive disorder that especially affects your perception of reality. Symptoms usually begin in adolescence or early adulthood. According to the World Health Organization (WHO), it affects 1 in 222 adults worldwide.

Schizophrenia is commonly associated with psychosis. This is a group of symptoms that includes hallucinations as well as:

A hallucination is a sensory experience that originates in your mind rather than from some external stimulus. A hallucination can affect any or all of your senses. For example, you might hear someone speaking who isn’t there or smell gasoline when there isn’t any present.

Hallucinations can be very convincing. You may not recognize them as hallucinations in the moment.

Not everyone who has schizophrenia will experience hallucinations, but it’s very common. A 2016 study found that 80 percent of people with schizophrenia had hallucinations, with 53 percent having hallucinations that affected multiple senses.

That being said, doctors recognize schizophrenia as a spectrum. You don’t necessarily have to have hallucinations to receive a schizophrenia diagnosis.

Many symptoms are associated with schizophrenia. Not everyone will have the same symptoms or the same level of severity.

No blood test or diagnostic scan can tell you whether you have schizophrenia. However, doctors sometimes use these tests to rule out other conditions with similar symptoms, especially those that can cause psychosis. Examples include:

To diagnose schizophrenia, a doctor will take your personal history. You can expect them to ask you whether you use any drugs, either medically or recreationally. They will also ask if anyone in your family has a history of mental illness.

Doctors often diagnose mental illness using the criteria outlined in the “Diagnostic and Statistical Manual of Mental Disorders.” The 5th edition, called the DSM-5, was published in 2013 and revised in 2022.

According to the DSM-5, a doctor can diagnose schizophrenia if you have at least two of the following symptoms:

Or, if you have only one of the above symptoms, you must have at least one of the below symptoms as well:

In addition to having symptoms that meet the criteria above, people with schizophrenia also have a hard time taking care of themselves or functioning at work or in social settings.

The previous version of the DSM, called the DSM-4, separated schizophrenia into five different subtypes. When the DSM-5 was released, the subtypes were all removed. Doctors now view schizophrenia as a spectrum and understand that its symptoms might change over time.

Even though the schizophrenia subtypes from the DSM-4 aren’t diagnosable conditions anymore, some people find that they’re still a helpful way to think about different groupings of symptoms.

Let’s look at the old schizophrenia subtypes and how they relate to hallucinations.

Paranoid schizophrenia

The grouping of symptoms once called paranoid schizophrenia are generally those most people associate with schizophrenia. While the DSM-4 was in use, this was the most common subtype of schizophrenia.

Paranoid schizophrenia was defined by a preoccupation with delusions or hallucinations, but without disorganized speech or behavior, and without flat or inappropriate affect.

Because hallucinations were central to a diagnosis of paranoid schizophrenia, this subtype would be fairly uncommon without them. Paranoid schizophrenia without hallucinations would have to include strong delusions.

Hebephrenic or disorganized schizophrenia

People with hebephrenic schizophrenia, also known as disorganized schizophrenia, had all of the following symptoms:

  • disorganized speech
  • disorganized behavior
  • flat or inappropriate affect
  • catatonic schizophrenia already ruled out

Hebephrenic schizophrenia encompassed all of the symptoms that paranoid schizophrenia explicitly excluded.

This subtype is an example of schizophrenia without hallucinations.

Catatonic schizophrenia

Catatonia is usually the result of a psychiatric condition, but can sometimes be caused by a physical condition. Catatonic schizophrenia was defined by at least two of the following groups of symptoms:

  • catalepsy (trance seizure with rigidity), waxy flexibility (remaining posed), or stupor
  • excessive movement without purpose
  • extreme negativism (resisting instructions or movements without motive) or mutism (inability to speak)
  • posturing (holding a position against gravity), stereotyped movement (frequent and repetitive movement without a goal), mannerisms (caricatures of typical actions), or grimacing
  • echolalia (repeating someone else’s speech) or echopraxia (copying someone else’s body movements)

Because the symptoms of catatonic schizophrenia involved the brain’s connection to the movement, it wouldn’t be unusual to have this subtype without hallucinations.

Undifferentiated schizophrenia

Doctors diagnosed undifferentiated schizophrenia if someone met the requirements for schizophrenia, but their symptoms didn’t fit into the other subtypes.

This schizophrenia subtype could include people with or without hallucinations.

Residual schizophrenia

Residual schizophrenia was used as a diagnosis when only negative symptoms were present or when the other symptoms were present but more subdued.

With residual schizophrenia, hallucinations would either be absent or less severe.

Does treatment change if you don’t have hallucinations?

Because schizophrenia is a spectrum that includes many different symptoms, your doctor will use a treatment plan that meets your particular needs. If you don’t experience psychosis, which includes hallucinations, you might not need to take antipsychotic medications as part of your treatment.

Hallucinations are common among people with schizophrenia. However, just because you don’t experience hallucinations, it doesn’t rule out having schizophrenia.

On the flip side, hallucinations have many causes. So, if you do experience them, it doesn’t necessarily mean you have schizophrenia.

To receive an accurate diagnosis and get proper treatment, you’ll need to work with a doctor. If you’re experiencing any form of psychosis, or if you notice drastic changes in your speech, thinking, or ability to relate to others, make a plan to meet with a doctor.