[The underrepresentation of complex patient groups in scientific research: ethical considerations]

Subgroups of patients with severe mental illness are underrepresented in scientific research. One of the possible causes is the fact that in these patient groups barriers may exist to the giving of competent informed consent.

Describing the ethical dilemmas that may occur when conducting research with these patient groups.

We present an overview of the Dutch legislation and regulation concerning participation in scientific research, and discuss the ethical dilemmas that arise in the mentioned patient groups. We present four directions for solutions.

In research with these patient groups more attention is needed for the explicit assessment and enhancement of competence. For the subgroup that is persistently incompetent, the possibilities of doing research with existing patient data without informed consent, need further exploration.

Further legislative development is needed for research with patients with severe mental illness who are persistently incompetent. Herein, it is crucial to involve ethicists and organizations representing patients' and relatives' perspectives.