Schizophrenia and dissociative identity disorder (DID), previously called multiple personality disorder, are commonly misunderstood as the same due to overlapping symptoms, such as dissociation from reality and decreased mental functioning. They each have distinct criteria that set them apart, but they can also occur together. Some estimates of people with comorbid schizophrenia and DID are around 20 percent. 

This article covers similarities and differences between schizophrenia and DID, the diagnosis of one or both of these conditions, and treatment.

Can You Have Schizophrenia and DID?

Schizophrenia and DID can look similar from the outside because they have some overlapping symptoms, but they also have important differences. DID is marked by distinct identities that come with changes in behavior, thoughts, and memories, and the switches between personalities can happen rapidly, causing distress. Schizophrenia is commonly misunderstood as meaning split personality and multiple personality, but it is more complex than that.

Schizophrenia and DID can cooccur, which means that a person with schizophrenia may experience symptoms of DID and vice versa. Specific criteria must be met for each disorder for it to be considered a comorbidity.

Differences

Symptoms of DID may appear similar to symptoms of schizophrenia at a high level, but they are different. One of the main differences between schizophrenia and DID is how dissociation from reality plays out. Schizophrenia is marked by a split from the reality experienced during psychosis while DID is more about dissociation due to different personalities that a person feels make up their whole self.

Some unique symptoms of schizophrenia that DID usually does not include are:

  • Delusions that include strong beliefs that aren’t true and/or are irrationalThoughts and thought patterns that are unusual or illogicalAbnormal body movements, such as repeating the same movement over and overLoss of interest in daily activities or social interactionDifficulty showing emotions

Similarities

Hearing voices that aren’t actually there is a hallmark of DID, and these voices represent the different personalities a person with DID alternates among. Someone with schizophrenia may also experience hallucinations in which they hear voices that aren’t there, but in the case of DID, a person may feel that these voices are trying to take control of their head. This is a core element of DID, while hallucinating voices is just one part of schizophrenia, though it is very common.

Another similarity between DID and schizophrenia is that symptoms may include memory problems. People with DID have gaps in memory of day-to-day events, trauma, and personal information. People with schizophrenia also experience memory problems, which may show up as having difficulty using information right after learning it.

The Problem With Diagnosis

An accurate diagnosis is crucial for a person to receive the right treatment for schizophrenia, DID, or both. Distinguishing between the two conditions takes expertise in using diagnostic tools, including the Diagnostic and Statistical Manual, 5th edition (DSM-5), which mental health professionals use to diagnose conditions. 

Myths among healthcare professionals about DID, such as that it is a rare condition and the same as borderline personality disorder, may lead it to be underdiagnosed and thus undertreated. In addition, according to the American Psychiatric Association, people with DID are often misdiagnosed as having schizophrenia because their belief that they have multiple identities is seen as a delusion, one of the categorical symptoms of schizophrenia.

Criteria Used

The DSM-5 has specific diagnostic criteria for each condition, but it does not include treatment. Usually, a certain number of symptoms must be present for someone to be officially diagnosed with a condition. A mental health professional would cross-reference symptoms experienced by someone suspected of having schizophrenia or DID with the criteria in the DSM-5.

For example, diagnostic criteria for schizophrenia include two or more of the following for at least one month: delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior, and negative symptoms. In the case of comorbid schizophrenia and DID, the criteria would need to be met for both conditions.

How Many People Have Both?

Studies have shown a wide range of comorbidity of schizophrenia and DID. A systematic review found that estimates of people with schizophrenia and a dissociative disorder range between 5% and 50%, with one study specifically finding that about 19% of people with DID also met the criteria for schizophrenia.

Another study of psychiatric outpatients in China found that about a quarter (24%) met the criteria for both schizophrenia and personality disorder (now known as DID); the researchers noted that some other studies found 22% to 28% comorbidity. More research is needed to better understand how many people have both schizophrenia and DID.

Risk Factors

Causes and risk factors differ between DID and schizophrenia. DID usually develops as a way to deal with trauma. Childhood trauma, including physical and sexual abuse, increases the risk of developing DID.

While the exact causes of schizophrenia are unknown, risk factors include genetics, environmental factors, brain chemistry, and substance use. As far as the inheritance of schizophrenia goes, the risk of developing it is higher among people with a family history than the general public, but most people with a close family member with schizophrenia will not develop the condition.

Treatment for Comorbid Mental Health Disorders

There is no cure for schizophrenia and DID but they are treatable. Appropriate treatment requires accurate diagnosis. Accurate diagnosis requires a mental health professional, such as a psychologist or psychiatrist, who may also provide therapy and/or prescribe medications.

Treatment for schizophrenia and treatment for DID both include psychotherapy, such as cognitive behavioral therapy. Prescription medications are also available for both schizophrenia and DID, but they are usually different; antipsychotics are common for schizophrenia, while antidepressants are common for DID. Treating comorbid mental health conditions can include a combination of treatments to manage symptoms and improve day-to-day functioning, such as maintaining social relationships.

Summary

Schizophrenia and DID have overlapping symptoms, which means some people are misdiagnosed or diagnosed with both. An accurate diagnosis of schizophrenia, DID, or both is critical to getting appropriate treatment.

A Word From Verywell

Schizophrenia and DID are commonly misunderstood. Our hope is that this article shows where the similarities and differences are to help improve understanding of these highly stigmatized conditions. Understanding the nuances between DID and schizophrenia requires professional mental health training, which is why it is important to speak to a healthcare provider about concerns and not assume a diagnosis based on symptoms. 

Comorbid mental health conditions may feel extremely burdensome for the person experiencing them, and seeking help can feel scary and overwhelming. But you are not alone in your experience. Help is available, and getting the right treatment can make a big difference in the day-to-day reality of living with schizophrenia and DID.

Frequently Asked Questions

  • What is the schizophrenia spectrum?
  • The schizophrenia spectrum includes a range of psychotic disorders. Schizophrenia is just one of these disorders. Others include:Schizophreniform disorderSchizoaffective disorderDelusional disorderBrief psychotic disorder
  • Do people with schizophrenia experience loose associations?
  • Hallucinations and delusions are symptoms of schizophrenia. For example, hearing voices that aren’t actually there is a common symptom of schizophrenia. People with schizophrenia may also strongly believe something that isn’t real, such as thinking people on the radio are sending messages that require a special response.
  • Is inappropriate laughter a symptom of schizophrenia?
  • Inappropriate laughter is not a defined symptom of schizophrenia, according to the National Institute of Mental Health. Inappropriate laughter is often a sign of an underlying neurological disorder, but schizophrenia is not one of them.
  • How do you manage schizophrenia and DID at the same time?
  • Many treatment options for managing comorbid schizophrenia and DID are available. Prescription medications and/or psychotherapy can help. Different medications and therapy modalities may be used for each of the conditions, and a mental health professional can help design appropriate treatment plans.

The schizophrenia spectrum includes a range of psychotic disorders. Schizophrenia is just one of these disorders. Others include:

Hallucinations and delusions are symptoms of schizophrenia. For example, hearing voices that aren’t actually there is a common symptom of schizophrenia. People with schizophrenia may also strongly believe something that isn’t real, such as thinking people on the radio are sending messages that require a special response.

Inappropriate laughter is not a defined symptom of schizophrenia, according to the National Institute of Mental Health. Inappropriate laughter is often a sign of an underlying neurological disorder, but schizophrenia is not one of them.

Many treatment options for managing comorbid schizophrenia and DID are available. Prescription medications and/or psychotherapy can help. Different medications and therapy modalities may be used for each of the conditions, and a mental health professional can help design appropriate treatment plans.