There is a significant gap between those in need of professional health care services for suicidality and those who actually seek help. Barriers for help-seeking include lack of knowledge, negative attitudes, stigma and limited access to health care services. Individuals with psychiatric disorders may also lack the cognitive resources that are required to seek help independently. Their social networks might therefore play a central part in help-seeking behavior. People in the social network may however not intervene when there is need for intervention due to barriers such as lack of knowledge about mental illness and treatment options, stigma and anxiety to engage with someone in crisis. Public awareness campaigns can address barriers for help-seeking, but requires knowledge about how the barriers work together. Theory of planned behavior (TPB) is the most widely used theory for understanding help-seeking for mental illness. The theory postulates that people make conscious decisions to act or not to act based on their attitudes, subjective norms and perceived behavioral control. While TPB has proved to be effective in explaining help-seeking intention, few studies have investigated how TPB can be used to develop and evaluate interventions to increase help-seeking. This talk presents a Norwegian study conducted to investigate how TPB can be used to develop and evaluate public awareness campaigns with the goal of increasing help-seeking for suicidality and the willingness to intervene against suicidality. We have developed a measurement instrument based on TPB, where the outcome variables are a) intention to seek help for suicidality, and b) intention to intervene against suicidality. The instrument has been tested in a Norwegian population sample and we have used confirmatory factor analysis to investigate the psychometric properties. Secondly, we have used structural equation modelling to investigate whether constructs of TPB can predict the outcome variables. Finally, based on our findings, recommendations are provided regarding the focus of public awareness campaigns to enhance both the intention to seek help and the intention to intervene against suicidality.