Unreal person
Depersonalization, derealization, and dissociation. They often complement each other. Psychiatrists even introduced a DPDR disorder at some moment and treat these three things as one, but are they really that similar? Let's make it clear.
The first feeling appears when you use incompatible patterns of behavior of class I. We expect that in major diseases. All patients with mania, depression, catatonia, and schizophrenia suffer from these internal conflicts, one way or another.
If you associate yourself with one process in a conflicting pair, you'll see a second one as... another you? It's weird. No. You do this thing. This is who you are. But that process is also you. Is that the real you? But if that you are real, then who is this you? You can easily confuse yourself into thinking that you're not you and your body isn't truly yours.
This puzzle is a central theme of depersonalization. It's based on fundamental conflicts in logic between the patterns.
Non-critical problems with sensors and data channels can cause anomalies in signals in our system, like phase shifts, delays, changes in amplitudes, etc. It's a completely different thing.
It may be hard to navigate in space or time. Sounds may feel muted or annoyingly loud. Colors may shift. A lot of effects can happen in a system with a complex wiring, including fuses-based intellectualization, but we have to remember that none of them come from memory. They aren't proper hallucinations, even if they look similar.
Channels can be compromised by various traumas and chemical imbalances, but, in all cases, altered subjective perception of reality requires memories of standard conditions. Individuals who are born with defective data channels don't know that something is wrong until we diagnose them by accident.
When a memory mechanism goes into a hot maintenance mode and loses synchronization, we get a true dissociation. Our graph of memories is corrupted. Some associations are being lost, some appear out of nothing. It's like amnesia combined with delusions. Additional dream-like hallucinations and effects like deja vu can appear during false readouts, but nothing here can disrupt the data channels or switches for patterns.
Patients with memory malfunctions may lose a clear sense of self or reality, but it's not necessary. Those problems are independent. Even in severe cases of multiple identities in a screwed memory graph, you won't feel any depersonalization as long as you don't try to mix logically incompatible behaviors.
In other words, these three issues aren't the same. Not even close. They can coexist, but should be treated separately.