Prevalence of mental health problems in children and adolescents from the outskirts of Sao Paulo City: treatment needs and service capacity evaluation.

To estimate the prevalence of mental health problems in children and adolescents, with or without considering global impairment, within a low-income urban community; to estimate the public service delivery capacity in terms of mental healthcare; and to determine the relationship between delivery capacity and treatment demand. Cross-sectional study. Probabilistic sample of clusters including all eligible households (low-income community - Embu, Southeastern Brazil). 479 children and adolescents (aged 6-17 years; attrition rate: 18.8%). 1) Clinical mental health problems in children and adolescents using the Child Behavior Checklist and/or Youth Self-Report total problem scales; 2) Global impairment: positive score in the Brief Impairment Scale (total score > 15.5); 3) Care service capacity: total number of cases annually seen by psychologists/psychiatrists in the health, education, juvenile justice, and child welfare sectors. Prevalence of mental health problems in children and adolescents: 24.6% (20.7-28.5) without considering global impairment; 7.3% (5.0-9.6) with global impairment (cases in need of treatment). Current annual service capacity can only provide care for 14.0% of impaired cases; approximately seven years would be necessary for all to be treated. Mental health problems in children and adolescents are frequent in the studied community, and the current structure of the community's public service system is not prepared to treat impaired cases in an adequate timeframe.