Dissociative identity disorder, bipolar disorder and schizophrenia: What's the difference?

A young woman's reflect in a damaged mirror

It’s easy to casually diagnose our friends or family members when their behavior baffles us.

A moody person might have us wondering: Bipolar disorder? Multiple personality disorder?

It could be neither. Possibly lack of sleep, or puberty.

The symptoms of many mental illnesses can overlap. Several mental illnesses can cause depression or anxiety and sometimes psychosis — losing touch with reality through confused thoughts and sometimes hallucinations.

It’s easy to confuse dissociative identity disorder, bipolar disorder and schizophrenia, especially, but all three are distinct illnesses with different treatments.

You can experience psychosis as well as depression when you have either schizophrenia or bipolar disorder. With bipolar disorder, which involves significant mood shifts, you’re more likely only to experience psychosis during one of the highs or lows of the illness.

However, schizophrenia, which is typically considered harder to treat than bipolar disorder, always comes with psychosis.

Here’s how I explain them to my patients and their families:

Bipolar disorder

What is bipolar disorder?

If you have bipolar disorder, you experience extreme fluctuations in your mood and energy level. Stress can trigger a depressive or manic episode, and those highs and lows may last up to several days.

During the highs, you might feel immense energy and be unable to sleep. You might take significant risks without thinking of the consequences such as gambling a large amount of money or using drugs or excessive alcohol. During the lows, you may withdraw or even be suicidal.

What age does bipolar start?

Typically, bipolar begins in the early 20s for both men and women.

Are you born with bipolar, or do you develop it?

Bipolar disorder is primarily inherited. Genes account for 80% of the cause of bipolar disorder; the remaining 20% depends on the experiences you have, such as trauma. One parent with bipolar disorder has about a 10% chance of passing the illness onto their children. When two parents have bipolar disorder, the odds increase to 40%.

Drawing his way to clarity after a bipolar disorder diagnosis


What is schizophrenia?

Schizophrenia is a chronic brain disorder that can cause you to experience hallucinations as well as confused and sometimes paranoid thoughts. You may think you’re being followed by the FBI or that you’re Jesus Christ. You may not be able to carry on a fluid conversation and instead jump from one topic to the next with little to no connection between the subjects.

What triggers schizophrenia?

It’s unknown exactly what causes schizophrenia. The mental illness is linked to several genes. If you’ve already inherited a risk for schizophrenia, using drugs or experiencing a head injury or intense emotional trauma can trigger the disease.

Schizophrenia is associated with high levels of dopamine, a neurotransmitter in the brain. And though dopamine causes feelings of pleasure, if you have schizophrenia, you have too little dopamine in the front of the brain and too much dopamine in the middle part of the brain.

At what age does schizophrenia usually begin?

Schizophrenia typically begins in the early 20s. For women, menopause can be another time when symptoms peak.

Dissociative identity disorder

What’s dissociative identity disorder?

Dissociative identity disorder (DID), sometimes called multiple personality disorder, is a very rare mental health condition in which you develop multiple identities after experiencing repeated trauma, usually in childhood, such as physical, emotional or sexual abuse.

You may be a 30-year-old woman, but your identities may be a 7-year-old girl and a 50-year-old woman, each with a different name and personality. Without even being aware of it, you may switch from one personality to the next when you’re reminded of the trauma you experienced. Sometimes one or more of the identities can be a different gender from your own. These different identities form as a way to disconnect or escape the memory of the trauma that caused them.

It’s much more common for people to experience post-traumatic stress disorder than dissociative identity disorder. PTSD is when you respond to a past trauma with physical reactions even though the situation isn’t threatening. You may experience a racing heart, fast-paced breathing and sweating in the absence of any threat but still remind you of your past trauma.

When does dissociative identity disorder develop?

Dissociative identity disorder usually develops in childhood — in children up to age 16.

Can dissociative identity disorder be cured?

Dissociative identity disorder isn’t curable, but it is treatable. You can go through therapy that focuses on the trauma you experienced that brought on the multiple identities. Exposure therapy can sometimes help you if you’re triggered by reminders of past traumas. With exposure therapy, a mental health clinician would help you face your fears associated with your past trauma.

That could mean, for example, standing in a subway station, sitting in a dark room or being in another setting where you experienced trauma in the past.

Whether you have dissociative identity disorder, bipolar disorder or schizophrenia, you have a lifelong illness that is treatable. With the right medications, your symptoms can go into remission.

We tell patients, “Don’t think because you feel better it’s gone. It’s not.”

If you stop taking your medication, your symptoms will return. Some medications can be given as an injection every few months, which takes the burden off patients having to remember to take a medication daily. With the right treatment — usually a combination of medication and counseling — you can go on and be successful in your life.

If you or a loved one is diagnosed with a serious mental illness, don’t think it’s the end of the world. It’s an affliction that needs to be addressed. There’s a lot of room for hope.

I wouldn’t be in this profession if I weren’t seeing encouraging changes in my patients. I do — every day.

Looking for confidential mental health treatment in a caring environment?

Ohio State's behavioral health team provides comprehensive care backed by one of the nation's leading academic health centers.

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