Types of Dissociative Identity Disorders: What Most People Get Wrong

If you’ve watched a movie featuring a character with "split personalities," you’ve likely seen a very specific, very dramatic, and usually very inaccurate version of what dissociation actually looks like. It’s not always about wearing a different hat or suddenly speaking in a thick accent. Sometimes, it’s just a weird, quiet blankness. You might be driving and suddenly realize you don’t remember the last five miles. Or you look in the mirror and the person looking back feels like a total stranger. We’re talking about types of dissociative identity disorders—a spectrum of mental health conditions that are often misunderstood, even by some people in the medical community.

These disorders aren't "quirks." They are sophisticated survival mechanisms. When a child experiences trauma so intense that their developing brain can’t process it, the mind does something radical: it compartmentalizes. It walls off the memory to keep the rest of the person functioning. Over time, those walls can become permanent structures.

Understanding the "Big Three" and Beyond

The Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5-TR), is the gold standard for these diagnoses. It identifies three main types, but there is a "catch-all" category that actually accounts for a huge portion of clinical cases. It’s not as neat and tidy as a numbered list might make it seem.

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Dissociative Identity Disorder (DID)

This is the one everyone knows—or thinks they know. Formerly called Multiple Personality Disorder, DID involves the presence of two or more distinct personality states. These "alters" or "parts" have their own way of perceiving the world.

Crucially, DID isn't just about having different moods. It involves "amnesic barriers." If one part of the system is out, the others might have no idea what happened during that time. You might find clothes in your closet you don't remember buying. You might meet people who know your name, but you’ve never seen them before in your life. Research by experts like Dr. Richard Kluft has shown that DID is almost always rooted in repetitive, early childhood trauma occurring before the ages of 6 to 9, when the "self" usually integrates into a single identity.

Dissociative Amnesia

This is more than just being forgetful. It's an inability to recall important personal information, usually of a stressful or traumatic nature. It’s not caused by a head injury or a stroke. It’s psychological.

There are different flavors here. "Localized" amnesia means you forget a specific event or period. "Generalized" amnesia is much rarer and much more terrifying—you basically forget who you are entirely, including your past, your skills, and your family. Sometimes, this comes with "dissociative fugue," where a person might suddenly travel far away from home, completely unaware of how they got there or who they used to be. They might even start a whole new life under a new name. It's rare, but it happens.

Depersonalization-Derealization Disorder

This one feels like living in a dream—or a nightmare.
Depersonalization is the feeling that you are an outside observer of your own body. You feel "spaced out" or like a robot.
Derealization is the sense that the world around you isn't real. Objects might look the wrong size, or people might seem like 2D cardboard cutouts.

The weirdest part? People with this disorder know their perceptions aren't real. They aren't hallucinating. They know they are in their body, it just doesn't feel like it. It’s incredibly distressing.

The "Other" Category: OSDD

Honestly, the most common diagnosis you’ll see in specialized clinics isn't "textbook" DID. It’s Other Specified Dissociative Disorder (OSDD). This is used when someone has clear dissociative symptoms that cause significant distress, but they don't quite tick every single box for the other diagnoses.

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For example, OSDD-1 is very similar to DID. However, the person might not have clear amnesic barriers (they remember what their "parts" do), or the parts might not be fully distinct personalities. They might just feel like different "versions" of themselves that they can't control.

Why Do People Get This So Wrong?

The stigma is massive. Pop culture portrays these disorders as dangerous or "creepy." In reality, people with dissociative disorders are far more likely to be victims of further violence than to be perpetrators.

There's also the "Fads and Fallacies" argument. Back in the 80s and 90s, there was a moral panic about DID, leading some to believe it was entirely "iatrogenic"—meaning created by therapists. While we now know that's largely false (brain scans of people with DID show distinct neural activity between alters that can't be faked), that skepticism still lingers in some ERs and GP offices. It makes getting a diagnosis incredibly hard. On average, people spend seven years in the mental health system before getting an accurate diagnosis of a dissociative disorder. Seven years. That's a lot of misdiagnoses of Bipolar or Schizophrenia.

How the Brain Actually Changes

We have to look at the biology. Chronic dissociation changes the brain's architecture. The amygdala (the fear center) is often overactive, while the prefrontal cortex (the logic center) struggles to keep up.

In people with DID, the hippocampus—which handles memory—is often smaller than average. It’s as if the brain physically shrunk the area responsible for recording life events because those events were too painful to store. Neuroscientist Dr. Simone Reinders has conducted fascinating imaging studies showing that "emotional" personality states and "neutral" personality states respond differently to trauma cues. One part of the brain is "stuck" in the trauma, while the other part is trying to get through the grocery list.

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Realities of Daily Life

Living with these types of dissociative identity disorders is exhausting. Imagine losing four hours of your day. You "wake up" in a park and realize you've missed a meeting. The "switching" isn't always a dramatic shift in voice or posture; it’s often subtle. A slight change in eye contact. A different tone of voice. A sudden shift in opinion or preference.

Many people with these conditions are "high functioning." They hold down jobs, raise kids, and pay taxes. But they do it while carrying a heavy internal load that most people can't even imagine. They are master "maskers."

Actionable Steps for Support and Recovery

If you suspect you or someone you love is dealing with a dissociative disorder, don't panic. These are treatable. The brain is plastic, and healing is possible.

• Seek a Specialist: General therapists often aren't trained in dissociation. Look for professionals who specialize in "complex trauma" or "dissociation." Check the International Society for the Study of Trauma and Dissociation (ISSTD) directory.
• Prioritize Grounding: When you feel "floaty" or like the world isn't real, use your senses. Hold an ice cube. Smell something strong like peppermint. Name five things you can see right now. This pulls the brain out of the "survival" mode and back into the present.
• Journaling is Key: If you have amnesia, keeping a shared journal can help different "parts" communicate. It creates a bridge across the memory gaps.
• Validate the Trauma: Recovery starts with acknowledging that the dissociation served a purpose. It saved your life when things were unbearable. You don't have to "get rid" of the parts; you have to learn to work with them as a team.
• Education is Shielding: Read books like The Haunted Self or Coping with Trauma-Related Dissociation. The more you understand the "why" behind the "what," the less scary the symptoms become.

Dissociation is a brilliant, desperate move by a child's brain to stay alive. It's not a monster in a movie. It’s a survival story that is still being written. Finding the right path forward takes time, but the integration of self—or at least functional multiplicity—is a goal well worth the effort.