There is little current interest in research into patients' attitudes toward medications. In the 1960s, psychiatric researchers including Uhlenhuth, Rickels and Covi focused on this area, but this research topic needs to be revived in the 21st century. The Health Belief Model may hold potential for doing this. This model was initially developed by 2 health psychologists, Rosenstock and Becker, to explain why patients did not follow medical interventions. The application of this model to study medication adherence in psychiatric outpatients has provided multiple findings including the conclusions that adherence is associated with: (1) the balance between internal and external health control beliefs, (2) psychological reactance, (3) patients' attitudes toward prescribed drug treatment in general and (4) the balance between the necessity of taking medications versus the concerns derived from adverse drug reactions (ADRs). Poor adherence is associated with several cognitive styles of patients, including: (1) high internal and external health control beliefs (patients who feel that their health is controlled both by external factors and their own beliefs), (2) higher psychological reactance, (3) pharmacophobia (present in 1/6 patients) and (4) skepticism about medications (a high concern for ADRs and a low belief in the necessity of taking medications). All of these findings suggest that shared decision-making is particularly important in fostering adherence in psychiatric patients. Two wider applications of this article can be made: (1) opening psychiatry to advances in clinical psychology and (2) expanding studies on attitudes toward medications to other medical disciplines.