Other Specified Dissociative Disorder

Other Specified Dissociative Disorder (OSDD) is a diagnosis in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR), and covers Partial Dissociative Identity Disorder (P-DID) in the International Classification of Diseases (ICD-11). This post details the different subtypes of OSDD according to the DSM-5-TR, and provides the ICD-11 equivalent.

OSDD is a dissociative disorder diagnosed when the patient has significant dissociative symptoms but doesn’t fit the criteria for any other dissociative disorder (that is, Dissociative Identity Disorder (DID), Depersonalisation / Derealisation Disorder (DP/DR), and Dissociative Amnesia). OSDD has four specifiers - type 1, which is equivalent to Partial DID in the ICD-11, type 2, 3 and 4.

OSDD type 1

OSDD 1 is perhaps the most well known of the Other Specified Dissociative Disorder types. In the DSM-5-TR, it’s called “Chronic and recurrent syndromes of mixed dissociative symptoms”, and gives the following description:

“This category includes identity disturbance associated with less-than-marked discontinuities in sense of self and agency, or alterations of identity or episodes of possession in an individual who reports no dissociative amnesia.”

Simply put, it’s DID but missing a symptom. The “less than marked discontinuities in sense of self and agency” part refers to someone who experiences DID but their alters aren’t fully elaborated or separate, which in DID communities is referred to as “OSDD 1a”.

The “alterations of identity or episodes of possession in an individual who reports no dissociative amnesia” part refers to someone who experiences DID without amnesia between alters. In DID communities this is called “OSDD 1b”.

(See this tumblr post on the differences between OSDD 1a and b).

In the ICD-11, OSDD 1 is a separate diagnosis called Partial DID (P-DID). It describes DID where only one alter is active in daily life with occasional switches or passive influence from other alters, usually fragments. This diagnosis covers OSDD 1b, but doesn’t account well for people with OSDD 1a. It also doesn’t account well for people with OSDD 1b who have well developed alters.

(See this tumblr post about Partial DID and OSDD.)

OSDD 1 is the only disorder other than DID that involves alters.

OSDD type 2

OSDD 2 is described in the DSM-5-TR as “identity disturbance due to prolonged and intense coercive persuasion”. A person with OSDD 2 has gone through some kind of experience that resulted in questioning their identity and sense of self. This could be torture, brainwashing, thought reform, political imprisonment, indoctrination, or involvement in a cult or terrorist organisation.

For example, an atheist adult who became involved in a religious cult eventually leaves, but is confused and distressed over their new religious beliefs.

OSDD type 3

OSDD 3 is a diagnosis given when a person experiences short term dissociation to a stressful or traumatic event. The dissociation doesn’t last longer than a month; if it did, the diagnosis would be changed to a different dissociative disorder (e.g. DP/DR).

OSDD type 4

OSDD 4 is a diagnosis given when a person experiences a dissociative trance. The dissociative trance can include involuntary movements or transient paralysis.

In the ICD-11, this is equivalent to Trance Disorder.

FAQs

  • Are alters part of OSDD 2, 3 and 4?
  • No. DID and OSDD 1 are the only disorders that involve alters.
  • Can I be diagnosed with more than one type of OSDD?
  • No. Generally, clinicians don’t diagnose “OSDD type 2”, they only diagnose “OSDD”, although they may specify on paperwork, or during a session, that it’s type 2. OSDD is a singular, catch-all diagnosis with 4 examples given of different presentations.
  • Can I be diagnosed with OSDD and another dissociative disorder?
  • OSDD is supposed to be a diagnosis for someone who doesn’t meet the criteria for any other dissociative disorder. So if you meet the criteria for DP/DR, for example, you probably won’t be diagnosed with OSDD.
  • Can I be diagnosed with OSDD and another disorder that isn’t dissociative?
  • Yes! OSDD can be diagnosed alongside any non-dissociative disorder.
  • What is Unspecified Dissociative Disorder?
  • Unspecified Dissociative Disorder (U(S)DD) is a short term diagnosis given when there’s not enough time or evidence for a more thorough assessment, or if the diagnosing clinician chooses not to specify what dissociative disorder the person has.
  • What are the other dissociative disorders included in the ICD-11?
  • The ICD-11 includes:
    • Dissociative Identity Disorder
    • Partial Dissociative Identity Disorder
    • Dissociative Amnesia
    • Trance Disorder
    • Possession Trance Disorder
    • Depersonalisation / Derealisation Disorder
    • Other Specified Dissociative Disorder
    • and Dissociative Neurological Symptom Disorder.
  • What is Dissociative Disorder Not Otherwise Specified?
  • Dissociative Disorder Not Otherwise Specified (DDNOS) was the name for the DSM-IV’s version of OSDD. When the new DSM came out in 2013, DDNOS was changed to OSDD. You might still see people who were diagnosed under the old DSM use DDNOS, since that’s what they were diagnosed with at the time.

Resources

Help! I’m dissociating!

Dissociating and need some grounding tools?

A loved one is dissociating and you don’t know what to do?

I would love to hear from you if you have any resources or experience (lived or otherwise) with OSDD 2, 3 and 4, as information about these subtypes is hard to come by!