In former eras of human existence, when knowledge was a privilege of the ruling guilds, such as nobility and clergy, even illnesses like epilepsy or katatonia were seen as a demonic possession, and the sickers weren’t only decried but also “cured” in a totally wrong way, such as an exorcism with implemented a huge physical punification, which caused great damages in the physical and psychological constitution. People with such psychical distortion were often victims of these clerical activities, their pain always grew and many of them committed suicide.

Johann Joseph Gassner, priest in „Klösterle“ in the bishopric Chur (18th century), who saw himself as a healer of sickness in the name of the lord, divided the people who gere given to him (mostly forced) and their sicknesses into the categories:

Many of this „sickers“ were healed so efficient, that constant psychological distortions showed up every day. Of course, in the case of this so called healer and every comparable case of religious diligence, the game with people’s fear was reason for these excesses; because only the one who fears the unknown is ready to turn to this alleged belief with its imagined god and the particular representants on this earth.

In the more enlightened society of the twentieth century and today, the knowledge about psychological distortion is much bigger, and all the illnesses who were former signs for demonic possession are now treated with psychology or medicine.

But let’s have a closer look at the different sicknesses of soul, spirit and body and the symptoms who let people believe in a demonic possesion.

Epilepsy is a neurological spasmic sickness which causes a paroxysmal (comes in attacks) and cortical (coming from the cerebral cortex) excharge of electrical potentials, which leads to a decrease of the standard membrane potential and causes an attack. The attacks show in a changement in brain function of different length, influencing motorism, ability to speak and conscience. During this there can be convulsions trough the whole body and in extreme cases also foam around the mouth.

This makes clear that some servants of the „holy lord“ saw this as a clear sign for a demon possessing the victims body. Because the ability to speak is very bad during an attack, this means you only roaring, these sounds were interpreted as the ones of the demon.

Catatonia is seperated into two different forms:
1. catatonian blockade: The sick person is completely numb like a statue, answers no questions, follows no order and is completely seperated from the world surrounding it. The person is awake; usually this state is accompanied by illusions, distortion of feeling and thinking.
2. catatonian state of uproar: grave psychomotoric uproar with sensless beating around, which is making the sick person weaken very fast.

There they saw a demonic pression, beating around was seen as a last reaction to avoid the demons attacks, where they wanted to bestead the victim with religious help.

Tourette-syndrom (Tic)  is a combination of several vocal and motoric tics in a chronic way (the tics appear several times a day). There are motoric tics like spontaneus, fast, repetetive movement of for example the eyeslids, head, shrugging, making grimaces or verbal ones like sudden coughing, grunting, hissing or swearing, or the repetation of some noises of words.

In this case, they saw a total possession of a men by a demon, because he apparently spoke with his grunts trough his victim and insulted the present „helpers“. People with such disease were victims of the most horrible exorcistic ritual which often killed the sicker.

Dissocial identity crisis (formerly called multiple personality distortion) is characterized by the appearance of two or more (often up to a thousand) different identities or states of personality, which take control over the sick person. For at least some of the personalities (called alter egos) it comes to amnesia for certain happenings, while another personality has taken over control. If a person comes into an extreme situation, there is a flood of stimulations in the brain, and a way out is needed. If this person is capable of great dissociation, which means being capable of seperating thing which belong together in mind, find rescue for their soul in this unfortunate situation. They separate their mind from reality and imagine another situation. Often this leads to a temporary amnesia, because in this time span, “another person” was acting.

Because the person behaves and intonates differently, these phases were interpreted as phases of possesion, where the demon rules over the body. Every try to exorcise the demon were apparently successful, because the return of the other, not “possessed” person and its amnesia was seen as a sign that the demon was pushed back successfully. These people were the poorest victims of this “friednly” so called experts, because they fell again and again back into the state of the alter ego and had to stand another exorcism.

So we can cleary see, for all these signs for possession which were diagnosed in religios diligence there are real psychological and medical explanaitions and scientific ways of healing to help the sickers instead of leading them into an even deeper crisis with realigious motivations to bind them to a certain belief.

Another modern aspect for demonic impact in the human mind is the phenomenon of running amok.
Originally coming from the javan word amoak = kill, this term is since the middle of the 19th century synonym for violence of a single person, which is directed on groups of people, apparently withouth any reason. This accords to the origin of the word, because there was a ritual at certain malayan tribes, where a person intoxicated by opium killed everyone he met with a dagger. The nourologist and psychiatrist Lothar Adler is, in an actual survey, dividing the symptom of running amok into four phases: