Objectives: Despite being recognized as a serious public health concern, suicidality among adolescents and young adults is frequently missed, and completed suicide remains the second leading cause of death for young Canadians. With such close links between depression, suicidality, and completed suicide, any intervention must address all 3 of these issues. However, to develop effective interventions, we must understand the types and rates of mental health service use among adolescents and young adults. This study examines service use rates in young Canadians with depression and suicidality and the influence of sex on the types of service provider chosen. Methods: We used data from the Canadian Community Health Survey: Mental Health and Weil-Being. Our sample included 619 individuals, aged 15 to 24 years, who screened positive for depression and suicidality in the past 12 months. We examined mental health service use rates in general and by provider type. Results: Among adolescents aged 15 to 18 years with depression, 40% had not used any mental health services. This rate was higher for adolescents with suicidality at 50%. In young adults aged 19 to 24 with depression, 42% had not used any mental health services. Among young adults with suicidality, 48% had not accessed services. Female adolescents and young adults were more likely to receive services from nonspecialty mental health providers. Conclusions: In Canada, many adolescents and young adults with depression and suicidality do not receive mental health services. Further, there may be a preferential treatment of young men by mental health specialists. Further research is needed to understand the quality of care received by these young Canadians and the factors influencing service use. (Can J Psychiatry 2007;52:228-232) Information on funding and support and author…