Knowing the exact criteria to maintain a DID diagnosis may help you identify whether or not you need a psychological evaluation to confirm your suspicion. According to the Diagnostic Statistical Manual (DSM-5), the primary diagnostic tool used in psychology, there are five criteria that must be met for a person to be diagnosed with DID. All five must be verified before a diagnosis can be made. They are:  There must be two or more distinct states within a single individual, which is outside societal and cultural norms for the individual. The person will have recurrent memory issues such as gaps in memory of everyday activities, forgetting personal information, or traumatic events. The symptoms cause significant impairment in functioning (school, work, home, relationships). The disturbance is not part of a widely recognized religious or cultural practice. The symptoms are not the result of substance abuse or a medical illness. A lot of times, DID is painted as a mental illness that shows up once or twice among an entire country of people; it is made to seem very rare. However, recent studies suggest that between one to three percent of the population actually suffer from the illness, putting it in the normal range for mental illness diagnoses. Keep in mind though, that the severity of the illness does vary from person to person. Whether as a result of social conditioning or because of a general increased likelihood for women to suffer significant traumatic abuse as children than do men, women are three to nine times more likely to be diagnosed with DID than are men. Further, women tend to manifest more states/personalites than do men, having an average of 15+, while men have an average of eight+.

Summary:
Learn the specific criteria for a DID diagnosis. Recognize DID is a common disorder. Know that DID is many times more likely to be diagnosed in women, than in men.