Psychiatrist Marlene Steinberg's pioneering research in the '90s at Yale University School of Medicine resulted in the first objective screening protocol for dissociative disorders. A screening tool, the SCID-D-Revised, based on Steinberg's comprehensive diagnostic criteria, is the current "gold standard." The SCID-D allows a trained therapist to evaluate five core symptoms, which may be experienced in varying degrees by survivors of trauma or abuse. These symptoms are:

* Amnesia -- the inability to recall a specific block of time or the feeling of "lost time." Unlike forgetting where you left your keys, these gaps in memory are significant -- ranging from several minutes or hours to days, weeks, months and even years.

* Depersonalization -- periods of feeling detached from yourself or observing yourself as an outsider. You may also feel separated from parts of your body or feel detached from your emotions.

* Derealization -- periods of feeling detached from your environment, having the sense that the environment is strangely unreal or foreign, often involving people who were previously familiar to you.

* Identity confusion -- feeling uncertain, puzzled or conflicted about who you are. You may feel as though an ongoing struggle is going on inside you to define yourself, including your sexual identity.

* Identity alteration -- a shift in role or identity, accompanied by changes in your behavior that are observable to others -- sudden mood changes, referring to yourself in the third person or using different names. You may feel as if your actions are not within your control.

Once the presence of these symptoms is identified and the extent to which they are experienced is established, a diagnosis of one of five core dissociative disorders can be made.

A three-minute online self-assessment (based on the SCID-D-Revised) for screening for dissociative symptoms can be found at