Sociological health research on the concept of trust has been bedevilled by its multivocalities. This article extends Luhmann's attempts to clarify a sociology of trust. Luhmann argued a semantic distinction between trust and confidence. In this article, we use empirical data on patient 'trust' in doctors to argue that there is also a semantic distinction between trust and dependence. We conducted 37 semi-structured interviews with patients with coronary heart disease in Adelaide, Australia in 2008 and 2009. Our findings indicate that risk, familiarity and time were critical to understand the distinction between trust and dependence. We argue that patients in situations of emergency (heightened risk) 'depended' on, rather than trusted, doctors, given the patients lack of familiarity with their doctors. Time was a mediating factor, as the more 'urgent' the situation, the more likely it was that dependence came into play, since the situation was 'unfamiliar'. Rather than juxtaposing trust and dependence, in this article we show how dependence may coexist with trust in the health care system in times of emergency.