[Capacity to consent to research in patients with mental illness].

Informed consent is a legal procedure when including a person in the treatment, diagnostics or research which includes information, voluntarism and capacity to consent of the participant. Capacity to consent is related to decision-making process and could be influenced by various factors. Assessment of capacity to consent is still clinical, because there are no widely accepted standards and assessment instruments. Persons with mental disorders could have some deficits in capacity for decision-making that could be temporary or permanent. Ethical considerations in the research with participants not able to consent are related to benefit vs. non-benefit studies and risk assessment. Finding of the better methods for capacity assessment and capacity enhancement could improve selection of the research participants. Legal recommendations, including international declarations and conventions, as well as the related Croatian laws are important mechanisms for safeguards of the persons with mental illness in biomedical research.