Aggressively sleep-deprived

‘There’s just no fuse left’

Most people would not like to run into a convicted criminal with psychological issues on any given day. Jeanine Kamphuis discovered that people like this are even more dangerous when they are suffering from sleep deprivation.
By Freek Schueler / Translation by Sarah van Steenderen / Illustration by René Lapoutre


Many forensic psychiatric patients suffer from sleeping problems. For these people, a good night’s rest can mean the difference between thoughtless violence and sensible action.

Forensic psychiatrist Jeanine Kamphuis studied the connection between sleeping problems, aggression, and impulsiveness. She received her PhD from the RUG last week.

She discovered a positive correlation: both the patients themselves and their therapists assessed the patients as being more aggressive as their sleeping problems increased. The chance of aggressive incidents also increased.

Kamphuis hopes that sleeping behaviours will from now on be included when the risk of recidivism for forensic psychiatric patients is assessed.

Future research will hopefully show whether an improvement in the quality of sleeping leads to less aggression.

Reading time: 5 minutes (915 words)

For forensic psychiatric patients, sleeping problems can be the proverbial last straw that leads to them committing an offence. Forensic psychiatrist Jeanine Kamphuis researched the connection between sleeping problems and aggression within this group and discovered a significant correlation. According to her, more attention should be paid to these patients’ sleep quality in order to prevent them from repeating criminal offences. Kamphuis received her PhD from the RUG on Monday of last week.

Apart from perhaps snapping at someone over coffee, healthy people suffer no disastrous effects after a night of bad sleep. But for people who suffer from low impulse control and aggression issues, a good night’s sleep may be essential.

Psychiatric patients suffer from sleeping problems more often than healthy people. This group of people, and forensic psychiatric patients in particular, also suffer from aggression issues fairly often. To find out if there was a connection between these two, Kamphuis interviewed over 100 patients in the Forensic Psychiatric Clinic in Assen and the Mesdag Clinic in Groningen. She also experimented with animals.


The first thing Kamphuis had to do was chart the alleged sleeping problems. Up until then, little research had been done on the influence a bad night’s sleep could have on forensic psychiatric patients. Questionnaires and interviews with patients showed that fifty per cent thought they were poor sleepers. One in three patients suffered from one or more sleep disorders.

Kamphuis also asked how aggressive the patients were feeling. ‘We found that a higher degree of sleeping problems correlated to more self-reported aggression and impulsiveness’, according to the forensic psychiatrist. In addition to the patients’ self-reporting, Kamphuis also included their therapists’ assessments in her research. This also showed a positive correlation: the more sleeplessness a patient suffered, the higher the chance that their therapist would label them as aggressive.

But it is not just about assessments. Aggressive incidents, such as fights, also turned out to be connected to the quality of sleep: ‘The chances of someone causing an aggressive incident in the clinic went up as their quality of sleep went down’, Kamphuis says about what she thinks is the most impressive result from her research.

Aggressive rats

However, a correlation between sleep and aggression does not say anything about cause and effect. It is like the chicken and the egg: are the test subjects having trouble sleeping because they are aggressive, or are they aggressive because they are having trouble sleeping? In order to answer that question, Kamphuis took a detour, as she calls it, into animal testing.

She forced rats to stay awake by placing them in a rotating wheel. Then, she checked whether these rats showed any abnormally aggressive behaviour when they were introduced to another rat. In contrast to earlier research results, Kamphuis saw no effect of sleep deprivation on violent behaviour.

Helping people

Kamphuis studied medicine at the RUG. She decided early on that she wanted to specialise in psychiatry. ‘How we treat each other, and the pathology of that in particular, is extremely interesting’, she says. ‘And as a psychiatrist, I can really help people.’ She did the last stage of her medical internship at the Forensic Psychiatric Clinic in Assen. After graduating in 2009, she started training to be a psychiatrist at the GGZ (Association of Mental Health and Addiction Care) in Drenthe, simultaneously starting her PhD research. According to Kamphuis, until then, very little research had been done on the possible influence of sleep deprivation on forensic psychiatric patients.

It was not exactly the result she was looking for, but there was an explanation: ‘It’s not like every single rat we keep awake becomes more aggressive. That’s why it’s so important to study which individuals react negatively to sleep deprivation.’

Just like not every single individual becomes aggressive due to sleep deprivation, the same can be said for rats. ‘But perhaps it was naive to think we could find a correlation in healthy rats, considering the extreme difference between forensic patients and healthy people’, according to Kamphuis.

Impulse control

To find out if people suffered from decreased impulse control after a bad night’s sleep, Kamphuis trained the rats to hit a pedal, which would reward them with a food pellet. Once they had figured this out, they were subjected to the next stage: the rats would only be rewarded if there were at least 30 seconds in between consecutive hits of the pedal. This meant the rats had to control themselves and not hit the pedal too often. Rats who were sleep-deprived turned out to have poorer impulse control.

This does not prove a direct relationship between sleep and aggression, Kamphuis emphasises: the issue is probably much more complex. Forensic psychiatric patients should be considered as extremes, and many suffer from trauma. ‘These people already have a short fuse, and sleeping problems could lead to there being no fuse left’, says Kamphuis.

She hopes that the quality of sleep will be included when the risk of recidivism for forensic psychiatric patients is assessed from now on. Will improving the quality of sleep lead to less aggression and fewer criminal offences? Kamphuis says that is a matter that future studies will have to show.


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