According to the report, the man claimed an "imaginary companion" compelled him to commit violent acts and attempt suicide, LifeScience reported.
The man also suffered from memory lapses.
"Possibly due to 'switching' to another personality state, he was losing track during the 'bloody' events, did not care who the victim was anymore, and remained amnesic to this part of his act," the report said.
The doctors diagnosed the man with dissociative identity disorder (DID), post-traumatic stress disorder (PTSD), chronic depression and alcohol abuse.
The doctors understood he was the first case of someone suffering from both 'vampirism' and DID. DID has been linked with childhood abuse and neglect, which the man had suffered as an adolescent.
Six weeks after his treatment, the doctors claim the man's blood-drinking urges were in remission, however his dissociative symptoms remained.
It is not known whether the man suffered any ill effects from the blood drinking, however consuming blood can result in haemochromatosis (iron overdose) or contracting blood-borne diseases, LifeScience reported.
- www.nzherald.co.nz