This report explores the suggested link between radicalisation, the foreign fighter phenomenon, terrorism and mental health problems, taking the situation in the Netherlands as a case study. After an initial mapping of the suggested link, including the presentation of new numbers, research is explored on the causes and mechanisms of radicalisation in relation to mental health issues in more detail. In particular, the social defeat hypothesis, addressing dopamine disturbance due to social exclusion, is discussed in relation to radicalisation. The paper subsequently examines possible responses and looks at some preliminary thoughts as well as concrete ideas, both more long-term and more short-term focused. Finally, the report offers a few thoughts on the way forward.