Sometimes I am asked to see a patient in the emergency department who is completely blind. They are looking around the room. I lifted their arm and it stayed in that position. Someone takes a blood test and they are not upset. They have not eaten or drunk anything for a day or two.

There are questions in your mind. What is wrong with them? Would they respond to someone else? Do they have a brain injury? Are they putting it on? How am I going to know what is going on if they don't tell me?

Catatonia is a severe form of mental illness where people have problems with movement and speech.

It can last from a few hours to weeks, months or years. There are people who have recurring episodes. I have spoken to many people about this condition.

What are people with catatonia thinking? Are they thinking?

It is easy to assume that a person is not conscious when they are unable to move or speak. This isn't the case according to recent research. It is the opposite.

People with catatonia often express intense anxiety and feel overwhelmed. It might be that people with catatonia have too many.

What are these thoughts? What could the mind do that would make you freeze? We tried to shed some light on this in the new study.

By looking at the case notes of hundreds of patients who had experienced catatonia, we found that a few had spoken about what had happened. Many didn't know or remember what was happening.

Some people said they experienced overwhelming fear. Some were aware of the pain of being rigid, but were unable to move. The people who had a rational explanation for the catatonia were the most interesting. One patient's notes were read.

I met him kneeling on the floor with his forehead on the floor. He said he had adopted the position to save his life and kept asking to be seen by a neck doctor … He kept talking about his head falling off his neck.

If you were to believe that your head was about to fall off, it would be a good idea to keep it in place on the floor.

It was voices that were telling them to do certain things. One person was told that moving would cause his head to explode. He thought God told him not to eat or drink.

The death feint that some animals show is one theory for catatonia. Prey animals will freeze when faced with a predator that is large or strong.

A patient in the study vividly described seeing a snake. It is possible that her body was adopting a primitive defense to a predator.

Catatonia is stuck between neurology and psychiatry. Understanding what people are going through can provide reassurance.

Jonathan Rogers is a clinical fellow in Psychiatry.

This article is free to use under a Creative Commons license. The original article is worth a read.