Dissertation for Medicine Doctoral degree at Sahlgrenska Academy, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry
Opponent: Professor Giovanna Parmigiani, Department of Law, University of Modena and Reggio Emilia, Modena, Italy
Examining committee: Professor Mia Ericson (chair), Professor Julia Korkman (Åbo) and Associate Professor Jennifer Strand
The disputation is held in English
Welcome to attend online via streaming, via Zoom Webinar: link to be announced
Chairperson of the disputation: Associate Professor Louise Adermark
Expert opinions can have a substantial impact on how offenders with mental disorders are handled within the legal system. The decision-making process leading to these opinions needs to produce reliable and unbiased conclusions. The overarching aim of this thesis is to explore what characterizes the decision-making process of experts working with Swedish forensic psychiatric investigations (FPIs).
Study I (interviews) shows that the decision-making process is flexible and organic, creating a potential for efficiency and precision, but also posing challenges for reliability and predictability.
Study II (case vignettes) examines experts’ use of multiple information sources. Experts typically integrate several sources, but the nature of the case affects how many sources are considered necessary. The results also show noticeable variation among experts regarding medico-legal issues, including whether the vignette cases meet criteria for severe mental disorder (SMD).
Study III (multi-stage case vignette) emulates the process in actual investigations. Experts formulate multiple, parallel hypotheses throughout the process and revise these as new information becomes available. Variation in opinions on SMD persists across decision points and is most pronounced at the final stage, when experts have received all information and report feeling most certain.
Study IV (interviews + 10-year cohort of court-referred cases for additional review) identifies characteristics that make medico-legal decisions difficult. Both experts and the court find ambiguous situations particularly challenging. While experts emphasize clinical complexity and gaps in clinical information, the court appears more influenced by factors related to the criminal act and the overall judicial process. The court also seems to use information about the experts’ decision-making process to judge the reliability of the final opinion.
In conclusion, there is a need to ensure that the decision-making process:
a) mitigates difficult situations that may jeopardize the reliability and validity of the final expert opinion,
b) systematically uses variation between experts to strengthen reliability, and
c) provides the court with the information needed to autonomously judge the reliability of the expert opinion.