Objective: To assess preferences for participation in shared decision making in a representative sample of psychiatric outpatients with affective disorders and to understand how clinical and socio-demographic variables influence patients’ preferences for participation. Method: A cross-sectional survey of 172 consecutive psychiatric outpatients with affective disorders attending at Community Mental Health Care setting was carried out. Patients expressed preferences on each of 3 aspects of decision making (seeking information, discussing options, making the final decision). The “CGI Severity and Improvement Scales” and the “Beck Depression Inventory” scale were used for severity assessment. Additionally the “Drug Attitude Inventory”, the “Beliefs about Medicine Questionnaire” and the “Leeds Attitude toward Concordance Scale” were applied to all participants. Effects of variables considered on preferences were assessed using proportional odds regression models. Results: We registered a high response rate of 85%. Nearly all patients (91%) preferred to leave final decisions to their treating psychiatrists and 87% preferred to rely on psychiatrists for medical knowledge rather than seeking their own information. In contrast, 81% of patients preferred to be offered options and to be asked their opinion by their doctors. Gender, age, educational level, number of psychotropics used and belief about psychiatric medication overuse were significant predictors in decision making dimensions considered. Conclusion: Shared decision making approach of patients with affective disorder must take into consideration a more doctor-directed approach preferred by the patients in which the desire to be offered options is not automatically linked with the willingness of taking decisions or getting more knowledge.