The mark of Depersonalization Disorder (DD) is a feeling of detachment from reality and from one's own body and thoughts. It is as if the person were an automaton, or in a dream, or observing from outside of her body and mind. Thus it is as though the person with DD had indeed lost his or her person. However, the person with DD is in contact with reality, and knows that things are not as they appear to her or him. The disorder must cause clinically significant distress or impairment, and must not be accounted for by another mental disorder or the effects of drugs or a medical condition. The depersonalization is usually a reaction to stressful events; after it goes into remission, it may reappear when the individual is stressed again. The depersonalization can last from as little as a few minutes to as long as many years. DD is seldom the complaint presented when individuals seek professional help; they are more likely to complain of depression or anxiety. Many normal people, perhaps half, have experienced fleeting moments of depersonalization. Persons with other mental disorders are even more prone to periods of depersonalization, as are people experiencing panic attacks or life-threatening stress.