I don't fully understand the language of this criteria for diagnosing Dissociative Amnesia. Could you help?

B. The disturbance does not occur exclusively during the course of Dissociative Identity Disorder, Dissociative Fugue, Posttraumatic Stress Disorder, Acute Stress Disorder, or Somatization Disorder and is not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a neurological or other general medical condition (e.g., Amnestic Disorder Due to Head Trauma).