Objective: To estimate structural and attitudinal reasons for premature discontinuation of mental health treatment, socio-demographic and clinical correlates of treatment dropout due to these reasons, and to test country differences from the overall effect across the region of the Americas.Methods: World Health Organization-World Mental Health (WMH) surveys were carried out in six countries in the Americas: Argentina, Brazil, Colombia, Mexico, Peru and USA. Among the 1991 participants who met diagnostic criteria (measured with the Composite International Diagnostic Interview (WMHCIDI)) for a mental disorder and were in treatment in the prior 12-months, the 236 (12.2%) who dropped out of treatment before the professional recommended were included.Findings: In all countries, individuals more frequently reported attitudinal (79.2%) rather than structural reasons (30.7%) for dropout. Disorder severity was associated with structural reasons; those with severe disorder (versus mild disorder) had 3.4 (95%CI=1.1-11.1) times the odds of reporting a structural reason. Regarding attitudinal reasons, those with lower income (versus higher income) were less likely to discontinue treatment because of getting better (OR=0.4; 95%CI= 0.2-0.9). Country specific variations were found.Limitations: Not all countries, or the poorest, in the region were included. Some estimations couldn´t be calculated due to cell size. Causality cannot be assumed.Conclusion: Clinicians should in the first sessions address attitudinal factors that may lead to premature termination. Public policies need to consider distribution of services to increase convenience. A more rational use of resources would be to offer brief therapies to individuals most likely to drop out of treatment prematurely. [ABSTRACT FROM AUTHOR]