Childhood abuse is not believed to be the only cause of Dissociative Identity Disorder. It appears that there also may be a biological link when it comes to DID. Many people who have Dissociative Identity Disorder have a family history of mental illness.he cause is believed to be childhood trauma, mainly physical and sexual abuse. Studies have shown that there is some type of documentation of abuse in about 95% of young patients with Dissociative Identity Disorder (Kluft, 2003).