Globally, this is rare. In countries like the UK and US, prisoners with mental health conditions often end up in the general prison population. But in the Netherlands prisoners are streamlined into specific segments following a charge. The idea is that this way, they can receive the proper, and particular, care they need.

I’m visiting Zwolle prison to understand what effect this segmentation has – and to what extent it helps those who are mentally unwell. My main focus is on how it affects women, following my in-depth piece last week looking at women with mental health issues in prisons. (Read more: Locked up and vulnerable: When prison makes things worse.)

Five levels of justice

One of the unique things about the Dutch criminal justice system is that a person can be judged to be responsible for their crime on five levels. “Dutch law differs from English law in that it recognises a sliding scale from full responsibility through to total lack of responsibility, with three levels in between,” explains one report in the journal Criminal Behaviour and Mental Health. While the diminished responsibility clause in the UK is similar, there is no such sliding scale.

Consider a situation where an individual takes drugs that contribute to a psychotic episode. If they then go on to commit a violent crime, they can be held responsible on some level, as they made the decision to take the drugs. But if the psychotic episode wasn’t drug-induced, they might be seen as less responsible for their crime.