The headline is dissociation.

Some stuff that falls under dissociation:

Derealization: The world seems unreal and/or lacking true depth.
Depersonalization: Has traits of derealization plus feels a disconnect to self and sometimes body. Like being in a dream or a movie. Or like life is happening to someone else.
Dissociative amnesia: Can be standalone or part of other dissociation. It is not limited to, but can create gaps for certain traumatic events.
A very common dissociative symptoms is getting numb.
DID: Two or more different personalities coexist in the same body, aware or unaware of each other, amnesia is present at times.
OSDD: Different personalities can be present but are often less distinct from each other and/or absence of amnesia, other forms exist as well.
Other dissociative phenomenons can be: Excessive daydreaming, dissociation towards body (for example to do with pain, heat and appetite), trance and twilight states (functioning but not being "in there").

Some types of dissociation is a diagnosis by itself, others are part of another diagnosis and some are personal patterns that are not seen as morbid enough to diagnose, some (rare in our culture) are wanted.