Myths and Causes: The Sleep–Dissociation Model

A Historical Myth About DID

For a long time, people believed dissociative disorders were just confusion between being awake and dreaming. In the 1800s, symptoms that we now connect to dissociation were called “somnambulism,” or sleepwalking. Doctors thought people were switching between a normal state and a sleep-like state.

Some researchers described dissociation as a “dreamy state,” where normal awareness sort of disconnects. Others believed depersonalization was like being halfway between dreaming and being awake. Over time, scientists started noticing similarities between dreams and dissociation — things like memory gaps, confusion about time and place, and even the presence of alternate “characters,” similar to alters in DID.

Today we know DID is much more complex than just dreaming. But these early ideas helped shape what later became known as the sleep–dissociation model.

The Sleep–Dissociation Model

The sleep–dissociation model suggests that unusual sleep experiences may be connected to dissociative symptoms.

Research has found strong links between dissociation and:

  • Nightmares

  • Very vivid or intense dreams

  • Recurrent dreams

  • Sleep paralysis

  • Sleepwalking

  • Waking dreams

  • Insomnia

For example:

  • People who have frequent nightmares tend to report higher levels of dissociation.

  • Individuals with nightmare disorder often show stronger dissociative symptoms.

  • People with DID report higher rates of sleepwalking compared to other psychiatric groups.

  • In some studies, more than half of DID patients reported nightmare disorder.

  • Almost half of certain borderline personality disorder groups with nightmare disorder also showed higher dissociation.

These findings have been repeated in many different studies, including both general population samples and clinical groups.

How Sleep Might Affect Dissociation

The idea is that when the sleep–wake cycle is disrupted, the brain may become more vulnerable to dissociative symptoms.

When someone is sleep deprived:

  • Dissociative symptoms increase.

  • Reality can start to feel more dreamlike.

  • Memory and awareness may feel less stable.

Research shows that even one night without proper sleep can increase dissociative symptoms in healthy people. Soldiers who experienced sleep deprivation during survival training also showed higher dissociation afterward.

This suggests that sleep problems don’t just affect mood — they may directly influence dissociative experiences.

Can Better Sleep Help?

Some research shows that improving sleep can reduce dissociative symptoms.

In one study, patients followed an eight-week program focused on improving sleep quality. As their sleep improved, their dissociative symptoms decreased.

This supports the idea that sleep disturbances and dissociation are closely connected.

Important Caution

Researchers also point out that the relationship may not be simple.

It could be:

  • One-directional (sleep problems lead to dissociation), or

  • Bi-directional (dissociation also disrupts sleep).

Other mental health conditions may also affect both sleep and dissociation at the same time.

How Trauma Fits In

The sleep–dissociation model doesn’t replace trauma explanations — it can actually work alongside them.

Childhood trauma may:

  • Disrupt normal sleep patterns,

  • Lead to long-term sleep problems,

  • Increase vulnerability to dissociative symptoms.

So in some cases, sleep disturbance may be one pathway through which trauma contributes to dissociation.

Why This Model Matters

This model gives us a new way of understanding DID and dissociative symptoms. It suggests that:

  • Sleep problems may not just be side effects.

  • They could play a direct role in symptom development.

  • Improving sleep might become an important part of treatment.

Overall, the sleep–dissociation model opens the door for new approaches that focus on stabilizing sleep as part of helping people with dissociative symptoms.