Hello, welcome!
If you are here, you are probably looking for answers on the difference between DID vs OSDD; Dissociative Identity Disorder (DID) vs Other Specified Dissociative Disorder (OSDD) vs Plurality. Maybe you have heard these terms and want to understand what they mean. Maybe you are wondering which one describes your experience. Maybe you are scared or confused. That is okay. You are in the right place and there is no rush.
DID vs OSDD vs Plurality – the short answer
DID stands for Dissociative Identity Disorder. OSDD stands for Other Specified Dissociative Disorder. Both are real diagnoses in the DSM-5-TR. Both can involve experiencing more than one identity, self, state, part or person within a single body. Both are valid. Neither is more important or more serious than the other.
Plurality is a wider community umbrella that includes DID and OSDD but is not limited to pathologizing experiences and labels. It is not a clinical term, it’s a community term people can use to self identify with. You can read more about Plurality further down in this article.
The main clinical difference between DID and OSDD is dissociative amnesia. DID includes it as a diagnostic requirement. OSDD does not. That is the simplest way to understand the distinction, but as we will explain below, it is not always that straightforward.
If you are new to all of this and want to start with the basics of what it means to be more than one, we recommend reading our article Welcome to Plurality, alongside this one.
What Is DID?
Dissociative Identity Disorder is a dissociative disorder. To receive a DID diagnosis according to the DSM-5, a person needs to meet the following:
- Two or more distinct identities or personality states, each with their own way of experiencing and relating to the world.
- Dissociative amnesia, described as gaps in memory for everyday events, important personal information, or traumatic events that go beyond ordinary forgetting.
- Significant distress or difficulty functioning in daily life because of the above.
- The experience is not part of a cultural or religious practice, and is not caused by substances or a medical condition.
DID is not rare. Research suggests it has a prevalence of 3.7% (Kate et al., 2019). Despite this, it is significantly underdiagnosed. It can take on average 6 to 12 years to receive a correct DID diagnosis, even while already receiving mental health care. The terminology around DID has also changed significantly over the decades, from MPD to DID to shifting criteria. You can read about that terminology history in our article; How they took the Multiple out of Multiplicity – Understanding the history of Dissociative Identity Disorder (DID) Terminology
What Is OSDD?
Other Specified Dissociative Disorder is also a dissociative disorder in the DSM-5. OSDD is a diagnosis of exclusion, meaning it applies when someone experiences symptoms of a dissociative disorder that cause clinically significant distress or difficulty functioning, but does not meet the full criteria for any of the named dissociative disorders.
In practice, the most common reason someone receives an OSDD diagnosis instead of DID is that clinically significant dissociative amnesia is not present, or is not recognised.
OSDD is not a lesser version of DID. It is its own diagnosis. Research shows that OSDD is actually more common than DID, with a prevalence of 4.5% compared to 3.7% (Kate et al., 2019). Yet it receives far less research, less media visibility, and less clinical attention. You can read much more about this in our article The ODDS of OSDD.
A note on OSDD-1A and OSDD-1B:
You may have come across the terms OSDD-1A and OSDD-1B online. These are not official clinical diagnoses. They do not appear in the DSM-5 and cannot be diagnosed by a clinician. They originated from a non-clinical website and have since spread widely through the community. Your experience is valid no matter what label you use, but we believe you have the right to know where these terms come from. We wrote a full article explaining this, which we strongly recommend reading: All about OSDD: an explanation about OSDD-1A and OSDD-1B. Which also contains a video created together with The Alexandrite System about their lived experience OSDD.
What About Amnesia?
The amnesia criterion is often treated as the clear dividing line between DID and OSDD, but it is not as simple as it sounds.
The DSM-5 does not actually use the word amnesia on its own. It describes gaps in memory that go beyond ordinary forgetting. But what counts as ordinary forgetting? That depends entirely on who you are. Ordinary forgetting for a 17 year old looks very different from ordinary forgetting for a 70 year old. It is a subjective criterion, and it is assessed differently by different clinicians.
This means that whether someone receives a DID or OSDD diagnosis can depend partly on how the clinician interprets this one criterion. That does not make either diagnosis less valid. It just means the line between them is not as firm as it might seem.
What About Parts vs People?
This is a common point of confusion so we want to address it directly.
You may have heard that in DID you have “parts” and in OSDD you have something less distinct. This is not an accurate way to tell the difference between the two diagnoses.
Some systems experience their headmates as distinct people. Some experience them as parts of one person. Some experience both, or neither, or something else entirely. This is true across DID, OSDD, and all forms of Plurality. In our own community census of 2025, we asked Plurals: “Are you alters, parts or self-states of the same one person?” Of the 831 people who answered, only 26.7% said yes. The rest described their experience differently, using words like people, headmates, selves, individuals, insiders, entities, and more.
How you experience who is in your system is personal. It is not what determines your diagnosis. If you want to explore more about what personhood means under the Plural umbrella, we wrote a full article on that here.
A note on Non-Plural OSDD:
OSDD is a diagnosis of exclusion (it “does not meet the full criteria for any of the disorders in the dissociative disorders diagnostic class” – DSM-5). Unlike most disorders in the DSM-5, it does not have its own detailed explanation text or diagnostic features section.
There is also significant community confusion around outdated terms like OSDD-1A and OSDD-1B, which are not in the DSM-5 and cannot be diagnosed.
Assuming that dissociation is a natural human experience, that happens at all sorts of intensities and during all sorts of activities, it is possible that not all (pathologized) forms of dissociation lead to Plurality-Multiplicity. Plurality as an umbrella is a community label, not a clinical one. It can only be self-identified with. No one can give it to someone or take it from them. As Plurals, as allies, as helpers, it is important to listen to the person in front of you, and to believe and validate their internal experience(s).
Having an OSDD or DID (diagnosis) does not automatically mean someone is Plural, unless they choose to describe and label their experience that way. It is always up to the person(s) to find the labels that best fit their lived experience. Having OSDD or dissociating a lot does not always indicate someone is Plural.
At The Plural Association, we write about OSDD from a Plural perspective, because that is the community we serve.
What Is Plurality?
Both DID and OSDD can fall under a wider umbrella that we call Plurality.
The Plural Association defines Plurality as anyone who self-identifies as having or being more than one individual within a single body, no matter the words they use to describe that experience.
Plurality includes many different experiences, there are as many ways to be Plural – as there are Plurals. Of course DID and OSDD fall under the Plural umbrella, but it is always up to the person/System to decide if they want to identify as Plural.
It also includes people who identify as Plural, as a system, as endogenic, as multiple, or with any other word(s) that fits their lived experience best. It includes experiences like Voice Hearing, channeling and much more. Hundreds of terms have been coined by Plurals to describe their experiences.
It includes people who have never sought a diagnosis, do not want one, or do not need one. Not everyone experiences their Plurality as a disorder, and that is completely valid. Having a DID or OSDD diagnosis does not automatically make someone Plural, unless they choose to describe their experience that way.
In our 2025 community Plural census, 92.3% of 869 respondents who answered this question, said they experience their Plurality as a neurodivergence. Neurodivergence means your brain works differently from what is considered typical, and includes experiences like being autistic, ADHD, dyslexic, and for many in our community, Plural. These can and do overlap — someone can be autistic and Plural, or ADHD and Plural, or any combination.
Plural is not a level to reach. It is not a clinical term. It is an identity, a community, and an umbrella. It can only be self-identified with. No one can give it to someone or take it from them. If it fits your experience, it is yours to use. If it does not, that is equally valid. If you want to explore whether Plurality resonates with you, our article How Do I Know If I’m Plural, is a good place to start.
Do You Need A Diagnosis?
No. A diagnosis can be life changing for those who need it. It can open doors to treatment, support, accommodations, and validation. But it is not a requirement for your experience to be real or for you to belong.
Many Plurals do not have a diagnosis. Some do not have access to one. Some do not want one. All of those are valid choices.
If you do want a diagnosis, please know that finding the right clinician can take time. DID and OSDD are still not well understood by many mental health professionals. Be patient with yourself in that process.
You Are Welcome Here
If this is your first time learning about any of this, it can feel overwhelming. That is normal.
You do not need to have it all figured out right now. You do not need to know which label fits. You do not need a diagnosis to start exploring. You are welcome in this community exactly as you are, wherever you are in your journey.
If you want to keep reading, here are some good next steps:
- 10 free resources for new and questioning systems
- The Plural Spectrum Tool, which shows there is no wrong way to be Plural
- Our FAQ about Plurality
Find Your Community
Exploring DID, OSDD, or Plurality on your own can feel isolating. It does not have to be. The Plural Association runs a safe, moderated community for Plurals of all kinds, whether you have a diagnosis, are questioning, or simply want to connect with others who understand.
You are welcome regardless of what labels you use or where you are in your journey. Join our community here.
Are You A Therapist Or Clinician?
If you are a mental health professional looking to better understand and support Plural clients, we are glad you are here. The fact that you are researching this matters.
DID and OSDD are significantly underdiagnosed, and many clinicians receive little to no training on dissociative disorders. The Plural Association offers training specifically designed to help therapists provide informed, respectful, and effective care to Plural clients. Learn more about our Plural Competence Course for Clinicians here.
References
Kate, M., Hopwood, T., and Jamieson, G. (2019) The Prevalence of Dissociative Disorders and dissociative experiences in college populations: a meta-analysis of 98 studies. Journal of Trauma and Dissociation. 4(29)
American Psychiatric Association. (2022). Diagnostic and statistical manual of mental disorders (5th ed., text rev.). https://doi.org/10.1176/appi.books.9780890425787
As always, we encourage you and your System to follow your own truth, to soul search, to find words, labels, visions, theories and communities that aren’t only within your values but also match your lived experience and/or long term goals, so that you might find belonging and don’t have to try to fit in.
Thank you for investing the time to read this article. Please, feel free to leave comments or feedback in the comment section.
The Plural Association is the first and only grassroots, volunteer and peer-led nonprofit empowering Plurals. Our works, including resources like this, are only possible because of support from Plurals and our allies.
If you found this article helpful, please consider making a donation.
Together we empower more Plurals!
About the authors
The Stronghold System are the proud volunteer founders & CEO of The Plural Association Nonprofit. They are from the Netherlands and reside in a 30-something-year-old body, are nonbinary, parents of an amazing child & 3 cats. They got diagnosed with Dissociative Identity Disorder over 10 years ago & also self ID as Plural.
Hi. My name is Shirley J. Davis and I live with DID. I am also a writer and own a site here on WordPress, DID in a Nutshell. I would love to help. I’m not a professional though. Just thought I’d offer. Thanks
Thank you for your comment Shirley. We have enough people working on the project for now. But feel free to join our FB group Power to the Plurals to share your personal input if you like! 🙂
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