While this era of digital technology brings great possibilities for improving the lives of many people with digital healthcare services, the design of these services in turn present challenges that are ethical in nature. Participatory Design (PD) values user involvement in design from a democratic, empowerment and ethical perspective. However, the design of digital healthcare services constitutes sensitive design situations, that is, situations that have the potential to negatively impact the participants. As a consequence, participation in these design situations involves risks, causing ethical dilemmas. The ethical dilemmas that designers face in sensitive design situations are situated, dynamic, diverse, unpredictable, and occur in-action. Yet, it is a complex field with little in situ support for designers who intend to involve users in sensitive design situations, and high complexity and risk increase the need to understand ethics in these situations. Consequently, this thesis intends to answer the question: How can users be involved in sensitive design situations?

The research question has emerged from the study of two design projects and is addressed through a Design Research (DR) approach. Both projects aimed at designing Digital Peer Support (DPS); one designs DPS for children between 8-12 cured from cancer, and the other designs DPS for people diagnosed with schizophrenia. The DR approach enables the study of de facto design situations in the two design projects. The thesis consists of a collection of five papers and a cover paper.

The results show that, in sensitive design situations it can be challenging to uphold the fundamental ethical commitments of PD: that participation is a democratic right, the user is the expert, design should enhance, and design is situated. Based on the empirical study, I propose four principles for ethics in sensitive design situations that aim to support the upholding of these ethical commitments: (I) the principle of enhancement; (II) the principle of acknowledgement; (III) the principle of advocacy; and (IV) the principle of accommodation.

The research contributes to the discourse on ethics in PD by expanding the understanding of ethical values of user involvement. Ethical guidelines must be dynamic and responsive, and participation should be carried out using methods for continuous critical reflection. The research contributes to practice by providing practical guidance for those who intend to involve users in sensitive design situations, ethical review boards who review PD, and for training of future PD researchers.