Dissociative Disorder: Not Otherwise Specified (NOS)

Dissociative disorder not otherwise specified is a former condition classification that mental healthcare professionals no longer use.

Before the classification change, older studies found that 8.3% of people experienced DDNOS. In contrast, studies have found that the most severe form of dissociative disorder, dissociative identity disorder (DID), is present in about 1% of the population.

Thus, DDNOS and the conditions that have replaced this former classification are fairly common.

The DSM-5 now includes five conditions in the category of dissociative disorders:

• dissociative identity disorder (DID)
• dissociative amnesia (DA), including dissociative fugue (DF)
• depersonalization/derealization disorder (DPDRD)
• other specified dissociative disorder (OSDD)
• unspecified dissociative disorder (UDD)

What used to be called dissociative disorder not otherwise specified (DDNOS) now falls mainly into the above categories of “other specified dissociative disorder” and “unspecified dissociative disorder,” although some people’s conditions may fall into other categories.

Dissociative identity disorder not otherwise specified is no longer a diagnosable disorder, according to the latest version of the DSM.

However, in all cases of dissociative disorders, the person would have dissociative symptoms that cause them significant problems or distress in key areas of their life, like with family, friends, or at work.

Dissociative symptoms the person might have depend on the specific disorder. They include:

• gaps in memory about certain events, time periods, or people
• you don’t feel a consistent sense of identity and might perceive that other personalities (or alters) sometimes take control of your actions
• you feel emotionally detached or numb
• you frequently feel like you are separated from your body and watching yourself from afar
• you experience other mental healthcare conditions and situations, such as depression, anxiety, and suicidal thoughts

Researchers have found that dissociative disorders are strongly associated with psychological trauma, particularly prolonged traumatic experiences in childhood.

Every version of the DSM seeks to improve upon previous versions so that mental healthcare professionals can use the classification system to provide diagnoses that are as accurate and precise as possible.

To serve that purpose, in its newest edition published in 2013, the DSM has broken down the classification of DDNOS into the classifications we list above.

A mental healthcare professional might diagnose someone who would have formerly been diagnosed with DDNOS with one of the following conditions:

• dissociative identity disorder (DID), which has broader criteria in the DSM-5 compared with before
• depersonalization/derealization disorder, which now also has broader criteria
• other specified dissociative disorder
• unspecified dissociative disorder

The last two in this list are new classifications created to replace DDNOS.

In both of these conditions, the person shows dissociative symptoms that cause them significant problems or distress. However, their dissociative symptoms may be less defined or frequent than the symptoms of someone with DID, for example.

Other specified dissociative disorder

Most people who would have been diagnosed with DDNOS with the previous version of the DSM would now be diagnosed with this condition.

Mental healthcare professionals use this classification in situations where they decide to specify the reason why the person doesn’t meet criteria to be diagnosed with a specific dissociative disorder.

Reasons a healthcare professional might specify include:

• The person has long-term changes in or questions about their identity after they experience prolonged, intense coercive persuasion, such as brainwashing, cult indoctrination, political imprisonment, or torture.
• The person frequently and repeatedly experiences dissociative symptoms, but they don’t have amnesia, or it’s hard to determine when or whether they felt breaks from their sense of self or felt like someone else was in control.
• The person experiences strong dissociative symptoms in reaction to stressful events.
• The person experienced a dissociative trance in which they became unresponsive but not as part of a normal cultural or religious practice.

Unspecified dissociative disorder

A person diagnosed with unspecified dissociative disorder would also have dissociative symptoms but would not satisfy all the standard indicators to be diagnosed with any of the other dissociative disorders.

It’s different than otherwise specified dissociative disorder (OSDD) in that the diagnosing healthcare professional decides they don’t want to specify why the person doesn’t meet the criteria.

Reasons for this could be:

• There’s not enough information available to make a specific diagnosis, such as in cases where a person has just come into the emergency room.
• The clinician decides for some other reason not to specify how the person did not meet the criteria.

If you think you might have a dissociative disorder, such as other specified dissociative disorder or unspecified dissociative disorder, consider reaching out to a licensed psychotherapist who has experience treating dissociative disorders.

You could ask a doctor to recommend a therapist or search for an expert yourself online. You can also try using this therapist search tool.

The National Alliance on Mental Illness offers this list of resources for getting help with dissociative disorders.

You can also learn more about dissociative disorders from these organizations:

• The National Alliance on Mental Illness (NAMI)
• The American Psychiatric Association (APA)

Whether you’re a mental healthcare professional or you’re experiencing dissociative symptoms yourself, you may be looking for more information on how DDNOS is diagnosed.

Though healthcare professionals no longer use DDNOS as a diagnosis, they have other ways to more accurately diagnose and treat people experiencing these dissociative conditions.