The codes of ethical conduct of the Australian Psychological Society and the American Psychological Association imply that researchers of adolescent depression and suicidal behaviour must plan to intervene to assess risk where a participant in a study indicates an intention to commit suicide. Participants in research of this kind need to be advised of this possibility in advance. The obligation to intervene, and to advise of the possibility of intervention, pose practical and methodological problems for research in this area but do not, it is argued, absolve the researcher of the primary responsibility to contribute to the welfare of the research participant.