Matthé developed and co-directs the Bochum SALUS project together with Jakov. Being trained as a philosopher, his primary task within the SALUS project is to analyze and clarify current debates about coercion in psychiatry from a conceptual and ethical perspective and to identify empirical assumptions in those debates for further empirical research. In addition, he is involved in designing and carrying out various empirical bioethics studies as well as in analyzing the data and interpreting the results.

Matthé received a PhD in philosophy from the University of Amsterdam and was a visiting scholar amongst others at UC Berkeley, the University of Tokyo and the National Institutes of Health. Alongside his BA and MA studies at the University of Amsterdam, he worked as an auxiliary nurse in a rehabilitation center.

His research interests include competence to consent, coercion in psychiatry, research ethics, mental health law and psychiatric advance directives.