Demonic possession is one of the most intriguing, disturbing, and poorly understood phenomena affecting the human brain. We’ve all heard stories, ranging from late-night TV episodes to urban myths passed around our communities, of otherwise normal, healthy people suddenly seeming to be possessed by demons. A person who is said to be possessed may act strangely, speak in a different voice or accent, or (according to legend) suddenly seem to acquire supernatural powers. Because apparent demonic possession is rare, there aren’t many medical reports about it, but doctors do have some idea of the medical conditions that can cause someone to seem possessed.
Some medical explanations for demonic possession include:
Dissociative Identity Disorder
Also known as DID, and formerly called multiple personality disorder, this rare condition may be responsible for many or most cases of what appears to be demonic possession. People with DID seem to cycle through personalities and identities, sometimes not even remembering what they did and said while acting as the “other” person. One fascinating report noted that in 29% of cases, if a DID sufferer’s “alter” identity is asked to identify him- or herself, the person claims to be a demon. It may seem both to the sufferer and to onlookers that the person has actually been possessed by a demon, but mental illness is to blame.
Complex Partial Seizures (Epilepsy)
One form of epilepsy causes complex partial seizures, which some doctors might call psychomotor seizures. A person having a complex partial seizure might move, speak, or act unpredictably, often engaging in bizarre behavior like wandering aimlessly while laughing or fumbling. Most people don’t remember these episodes after they happen. In antiquity, people with epilepsy were often believed to be possessed by demons, and, even today, complex partial seizures might look supernatural to someone who is very superstitious. Fortunately, epilepsy is almost always treatable, so any apparent “demons” vanish with anticonvulsant therapy.
Schizophrenia causes many disturbing symptoms including hallucinations and delusions. This may make a person believe that he is possessed by a demon. He may believe that demons are speaking to him and act accordingly. In other cases, the symptoms might be more vague: some people with schizophrenia have disorganized or nonsensical thoughts, and may jabber meaningless strings of words or sounds. These symptoms, especially if they all occur together, might look and feel like demonic possession, but they are ultimately the result of a mental illness that, fortunately, tends to respond to treatment.
Demonomania is the clinical term for a delusion of being possessed by demons. It is a form of psychosis, so it can occur as a result of almost any condition that could trigger psychosis. While DID, epilepsy, and schizophrenia are probably the most common medical explanations for demonic possession, other possible causes of psychosis include drug abuse, withdrawal from drugs or alcohol, certain medications, brain tumors, stroke, infections affecting the brain, and severe cases of bipolar disorder and depression.
It’s important to pay attention to the fact that almost all cases that seem like someone is possessed by a demon are actually signs of a serious medical problem. Someone who is suddenly acting very strangely or suffering from delusions or hallucinations needs urgent help (from a medical expert, not an exorcist) so don’t hesitate to seek it if those symptoms are happening to you or someone you know. Ultimately, thanks to science and medicine, demonic possession is not something that has to go unexplained or untreated.