ORCAT - Scientific research, consultation, and training.

ORCAT is an independent enterprise, focussing on three main themes:

  • Radicalization and extremism in relation to mental health;
  • Autism spectrum disorders in adults;
  • Advice on stalking related cases.
Get in touch


Research and Services

Activities comprise scientific research, consultation and advice, and training. Click here for a summary of publications.

Scientific Research

Current research topics explore the relationship between mental health problems, radicalization, violent extremism, and terrorism, with an active engagement in inter-agency collaborations on this theme. Other research projects are focused on the phenomenological aspects of autism spectrum disorders, and on stalking of mental health professionals by clients.

Consultation and Advice

ORCAT provides psychiatric expertise for management and diagnostic assessment* related to developmental disorders. Bram Sizoo is attached to the Centre for Consultation and Expertise (Centrum voor Consultatie en Expertise). Expert advice is offered on stalking and threat management to organizations and companies.


Tailored lectures and courses focus on intersections between radicalization, extremism, and mental health issues. Expert training is offered to professionals in both the security domain and mental health care sector. Tailor-made presentations are designed for select audiences.

* Assessments and second opinions are conducted exclusively after referral by a professional practitioner, the National Institute for Forensic Psychiatry, or the Ministry of Justice and Security.



  • Bram Sizoo

    Psychiatrist · bram@orcat.nl

    Bram Sizoo (1961) was a naval officer in the Royal Netherlands submarine service from 1982 to 1989. In 1992 he obtained a law degree. After his medical training he specialized in tropical medicine. In 1999 he became medical director of Mulanje Mission Hospital in Malawi. From 2003 to 2008 he was trained as a psychiatrist in Zwolle. In March 2010 he obtained his PhD on the thesis “Developmental Disorders and Substance Use Disorder, a phenotypical, endophenotypical and genetic exploration”. In 2008 he launched the Centre for Developmental Disorders, a certified top mental health (TOPGGz) unit within Dimence Mental Health Institution, where he was active until 2022. Since 2015 he has been employed by the National Police where he focuses on threat management. Bram supervises PhD students and is actively involved in several research projects.

Current and Past Relations

Met Police