The current studies explore causal models of heart attack and depression generated from American healers whom use distinct explanatory frameworks. Causal chains leading to two illnesses, heart attack and depression, were elicited from participant groups: registered nurses (RNs), energy healers, RN energy healers, and undergraduates. The domain-specificity hypothesis predicted that psycho-social and physical causes would not interact in illness models. Across illnesses, RNs and undergraduates rarely cited interactions between mental and physical causes, consistent with the domain specificity hypothesis. In contrast, energy healers frequently mentioned interactions. Study 2 showed that these differences were not due to salience. These results suggest that domain-specificity theory is supported for groups with extensive exposure to western medicine but does not explain energy models of illness. Implications for other cultural models of illness are discussed.