I once posted the same question. If only I could remember what the responses were. Darn brain. I do know that people experience DP and DR during a panic attack. Also, DP and DR are symptoms of schizophrenia. People with temporal lobe epilepsy also experience DP/DR. Brain tumor... that's another. Inefficient sleep, thyroid probs, and more but I can't remember them. Hope I haven't alarmed you.