The cause of Renfield’s syndrome is largely uncertain. The rarity of the syndrome, combined with its lack of formal recognition as a clinical diagnosis, makes the condition difficult to thoroughly study. Richard Knoll, the first psychologist to truly study the syndrome, believed that the condition stemmed from childhood trauma. Today, many psychologists believe that it is either a complication of schizophrenia or a form of sexual deviancy.
There is some evidence that childhood trauma does play a significant role in the development of Renfield’s syndrome. Several case studies of those with clinical vampirism report the violent death of a loved one during early childhood. Only in very few of these cases did the child actually witness the death. Nonetheless, these individuals formed a fascination with many things related to death, specifically blood and corpses.
Conversely, those subjects affected by Renfield’s syndrome who progressed beyond an obsession with blood to actual violence show clear indicators of schizophrenia. Delusions are common in clinical vampirism. Depersonalization of victims often occurs as well as generally disorganized thought. Individuals with this syndrome also have trouble thinking symbolically and may let blood in an attempt to prove that they or their victims actually exist.
As there is clearly a sexual aspect to Renfield’s syndrome, classification of the condition as a form of sexual deviancy may be appropriate. Those with this syndrome universally experience sexual arousal at the sight or taste of blood. Sexual sadism is extremely common in these individuals as are rape fantasies. Necrophilia and self-injurious masturbation rituals are also frequently observed in those with Renfield’s.
While it would be easy to believe that Renfield’s syndrome is the result of popular vampire fiction, examples of clinical vampirism predate the genre. It is believed that Bram Stoker’s Dracula, largely considered to be the pioneer novel of the genre, was actually influenced by a psychological text featuring a brief description of the syndrome. The psychological and fictional link came full circle when Richard Knoll paid homage to Stoker by naming the syndrome after a character in his novel.
There are clear distinctions between those suffering from Renfield’s syndrome and individuals that have developed a clinical obsession with vampires. While both conditions may present with the delusions, the obsession with actual blood is a Renfield’s trait. Those with obsessions influenced by popular culture tend to focus more on common fictional stereotypes of a vampire's physical abilities and lifestyle.