There is no set period of time. I've heard cases of several hours to several months. It all depends on the situation.
Depersonalization as a symptom (not as a disorder) is quite common in college-age populations
If you are worried that you are suffering from depersonalization depression and bipolar disorder, you will need to see a doctor. A doctor can offer treatment.
Depersonalization disorder is present in Schizophrenics in most cases, But Schizophrenics tend to develop Psychosis which disables them completely from reality, thus Schizophrenics are not aware nor can tell the difference between the internal and external world. Whereas individuals with Depersonalization disorder temporarly have fragmentation of reality.
Derealization and depersonalization sindrom.
Heather Nichol has written: 'Depersonalization'
How long does pleurisy last
For as long as they last.
WHY DOES STRIDE LAST LONG
How long is what going to last?