What are the dissociative disorders?
Rather than fight or flee in a stressful or threatening situation, some people “freeze,” said Dr. Frank W. Putnam, a professor of clinical psychiatry at the University of North Carolina School of Medicine and an expert on dissociative disorders. “That’s the dissociative state where you shut down and you kind of go away.”

“I had thought that the internet and app-based world would bring us all closer together. And it’s had exactly the opposite effect,” said Dr. David Spiegel, a Stanford University psychiatry professor who has worked with patients with D.I.D. for about 50 years. “It has fragmented us.”

What he means, he explained, is that many of us have retreated into our own online echo chambers.

Dr. Rettew encouraged anyone curious about a specific disorder to speak with an attentive and thoughtful health care provider, particularly one who understands trauma, to tease out what might be going on.

“Just about everything in mental health is dimensional. It exists on a spectrum,” he said. “And that doesn’t make our conditions less real, but it does make them more complicated.”

Although dissociation can help a person mentally escape during a threat, it can interfere with daily life when people continue to dissociate during benign situations.

Frequent experiences like that make dissociation pathological, Dr. Putnam said. It becomes a disorder when you space out and “lose time” long enough that it interferes with your life in a significant way, he added.

The three most common and well-known dissociative disorders are: dissociative identity disorder, depersonalization/derealization disorder and dissociative amnesia.

The most severe is dissociative identity disorder, formerly known as multiple personality disorder. Those who experience D.I.D. report having two or more identities.

Depersonalization/derealization disorder is thought to occur in about 1 to 2 percent of the population and is often associated with a history of verbal abuse, like shaming, that drives someone to want to disconnect from an emotionally traumatizing environment, Dr. Putnam said.

According to the A.P.A., those who experience depersonalization can feel at times as though they are detached from their mind or body — estranged from themselves — like they are watching events happen to them. Derealization, on the other hand, refers to feeling detached from the environment as though the people and things in the world are not real, in some cases appearing like cardboard cutouts.

The prevalence of dissociative amnesia is not well established. It occurs in response to a variety of different types of trauma, and involves having blocks of time where you lose your identity and are not able to recall important information about your life, such as your own name.