Hurlow et al ^{Reference Hurlow, Wilson and James1} contradict the assertion that severe mental illness does not have a significant role ‘overall in the area of terrorism’. The authors state that there is evidence for mental illness in cases of lone-actor terrorism, suggesting that these cases are more likely to come to the attention of psychiatrists.

I strongly disagree with the authors. Although there are several psychological factors contributing to radicalisation, experts in terrorism studies agree that those who commit acts of terrorism ‘are not mentally disturbed’. ^{Reference Alonso, Björgo, Della Porta, Coolsaet, Khosrokhavar and Lohelker2}

There is little consensus in the literature regarding the importance of mental illness in lone-actor terrorism. However, the evidence suggests that mental illness is not a key factor contributing to acts of violence in these cases. ^{Reference Danzell and Maisonet Montañez3} It is therefore erroneous to insinuate that psychiatrists have a role in identifying these individuals. It is also highly questionable whether a ‘future potential Breivik’ would – or could – be identified by psychiatrists. In the case of Breivik, the forensic psychiatric evaluation concluded that although he has narcissistic personality disorder, he was not affected by a serious mental disorder when committing the act of terrorism, nor at the time of the evaluation.

The role of individual preventive interventions is limited in preventing relapse in regular criminality ^{Reference Khoshnood and Väfors Fritz4} and remains highly controversial with regards to terrorism. ^{Reference Ranstorp and Ranstorp5} The question of terrorism and mental health is extremely relevant and important, and warrants further study. However, the evidence to date shows a weak correlation between mental disorders and terrorist acts.