Published: 20-09-2023 12:30 | Updated: 21-09-2023 11:08

Misinterpretations can sometimes lead to violent actions

Anette Johansson conducts research on what separates psychotic people who commit crimes from psychotic people who do not.

Anette Johansson is a Chief Physician of psychiatry and researcher at the Department of Clinical Neuroscience at Karolinska Institutet.

Anette Johansson Photo: Stefan Zimmerman

Text: Annika Lund, for the magazine Medicinsk Vetenskap nr 3 2023 / Spotlight on forensic psychiatric care

How to you investigate this? 

"We compare three groups: psychotic people who have been convicted or not convicted of a violent crime and people who are not suffering from a psychotic disorder. We interview everyone about previous trauma that they may have experienced, do aptitude tests and attention evaluation tests and take blood samples. We also examine the ability to understand other people's emotions and thoughts, something that requires the ability to interpret emotional expressions in others, so called emotion recognition. In these tests, study subjects are asked to watch a film where an actor shows different facial expressions and speak in a pretend language in a tone that matches their facial expression. After that the study subjects are asked to indicate what emotion was shown. 

How do they perform? 

"The test is quite hard, even a healthy person fails to score over 70 percent. But people with a psychotic disorder make misinterpretations. And people who have a psychotic disorder and have been sentence to forensic psychiatric care make even more mistakes. 

How should one look at this? 

"One hypothesis is that this groups has difficulties interpreting other people's moods. It makes it harder to interpret what is happening in a situation where there is conflict. It could possibly lead to them perceiving aggression where there is none. And then they might act on that misinterpretations, which may lead to a violent act. 

Why do some people have a hard time interpreting facial expressions? 

"We don't know, but there is research that indicates that perhaps their vision is not properly decoded. The mistake might occur when their visual impression is interpreted by the brain. Such a misinterpretation also occurs with visual hallucinations, which are also common with psychotic disorders. 

How are you planning on continuing your research on this? 

"We are hoping to create a number of parameters that differ between people with a psychotic disorder who have been convicted of a violent crime and people who suffer from psychotic disorder but have not been convicted of a violent crime. After that we want to monitor people who have recently developed a psychosis to see if these patients can used to predict future violence. We also want to examine whether treatments aimed at certain difficulties, for example emotion recognition, can reduce the risk of becoming violent towards others.