Im sorry but no one can tell you what the specific detailed differences and similarities are.

in short since March 2022, diagnostics, symptoms, problems and behaviors for mental disorders now depend upon deeper not found by typical media-based ways things (aka google, the internet, movies and so on), instead the focus is now on the more private how's, what's where's, when's, whys, durations, and more that are found only deep inside yourself.

in .......general ....... we can tell you what the DSM 5 TR says which is public information and won't infringe on your mental health rights to privacy and confidentiality.

Borderline Personality Disorder is listed in with the personality disorder category.

Dissociative Identity Disorder is listed in with the dissociative disorders category.

you will be able to find information about personality disorders in the DSM 5 TR pages 733- 778. Borderline personality disorder is located on pages 752-757.

you will find information about dissociative disorders in the DSM 5 TR pages 329-348. Dissociative Identity Disorder is located on pages 329-337.

If you read the diagnostic manual, you will see that borderline personality disorder is about how you feel about yourself and where you fit in with the world and those around you.

identity issues - its about yourself worth, your self-esteem, whether you are introverted or extroverted kind of person, trouble with relationships, sometimes seeing those around you as good or bad (aka splitting) the diagnostic manual also mentions frequent suicide and self-injury.

By reading the diagnostic manual you will see that Dissociative Identity Disorder is -

a trauma related disorder involving the brains' physical function called flight fight fawn freeze response. a person experiences a trigger, that trigger causes the brain to go into the panic mode of flight, fight fawn freeze response, causing a certain set of symptoms, problems and behaviors.

to outsiders and sometimes to those who have this disorder it may seem like they have changed into a completely different person, but the reality is that they are just responding to a trigger from the point of view of those past traumatic memories, emotions that have been removed from their conscious awareness and stored in their unconsciousness (aka repressed/dissociated)

you will also see that the diagnostic criteria for both disorders are vastly different, one rules out the other. they are totally opposite disorders.

by the way I saw someone mentioned the book ICD 11.

the ICD 11 is not a diagnostic manual. it is a coding manual primarily used for insurance companies; the ICD 11 is used hand in hand with the DSM 5TR.

Differences -

ICD 11 = summaries because insurance companies don't need to know all the great amounts of details about symptoms problems and behaviors like mental health treatment providers do, insurance companies don't need a guideline on how to treat mental disorders. they are not treating disorders they are paying for the treatment.

DSM 5 TR = detailed information because mental health treatment providers do need all the minute details and a guideline on how to treat those disorders.

ICD 11= separates some symptoms problems and behaviors into "add on" coding where a person must meet both the main code and also the "add on" code of the separated from the main disorder symptoms. this is because some insurance companies pay for this and not that.

example (PTSD + CPTSD) a person must meet both the main issues (PTSD) and the three separated issues (CPTSD).

some insurance companies don't pay for treatment resistant, long-term issues they sometimes have a "cap" on how much money / blocks they will pay out for.

DSM 5 TR does not separate long term treatment resistant symptoms, problems and behaviors from the main disorder label.

for example, with PTSD they have 8 categories, 24 symptoms problems and behaviors plus a specifying list of words, phrases, symptoms problems and behaviors to customize (fit the client's situation) with one disorder label.

there was no need in the DSM 5 TR for an "add on" label of CPTSD because those separated for insurance reasons, symptoms, problems and behaviors are already included in the one PTSD label.

Two books - one is a coding book primarily used for insurance purposes and the other a diagnostic manual, used for diagnosing and treating mental disorders.

they completely match up, but they do so in different ways because they have different purposes.

the same people (American Psychiatric Association and World Health Organization) worked together on both the DSM 5 TR and the ICD 11 to ensure they were matching up. one for detailed use and one for when only summaries are needed.

here in my location treatment providers use the ICD 11 for insurance and for when they want to limit the information a client gets, so as to not overwhelm them with a lot of details all at once.

If you are looking for just the basics (criteria and very limited information) the ICD 11 is what you want.

If you are looking for more than just the basics of criteria and summaries the DSM 5 TR is what you want.

suggestions -

talk with your treatment providers, they can go more into details based on your specific situations without compromising your rights to privacy and confidentiality.