Abstract
Less than 50% of patients with diabetes achieve the glycaemic goals recommended by the American Diabetes Association. The set of factors associated with adherence to treatment is very broad. Evidence suggests that psychosocial factors are related to medication adherence of patients with type 2 diabetes. Due to the lack of a clear statement from researchers regarding the relationship of psychosocial factors to adherence, an electronic search was conducted in PubMed, MEDLINE, Academic Search Ultimate, CINAHL Complete, Edition and Health Source: Nursing/Academic Edition using the following keywords "adherence", "diabetes", "social support", "stress", "anxiety and depression", "beliefs about medicine", "communication", "older age", "frailty", "cognitive impairment", "addiction", "acceptance of illness", "sense of coherence" obtaining 2758 results. After a narrowing of searches and reference scanning, 36 studies were qualified. The studies analysed showed negative effects of anxiety, diabetes distress, older age, poor communication with physicians, stress, concerns about medicines and cognitive impairment on levels of self-care and medication adherence. One study did not confirm the association of depression with adherence. Self-efficacy, social and family support, and acceptance of illness had a beneficial effect on medication adherence. In conclusion, the current evidence suggests that the relationship between psychosocial factors and adherence has reliable scientific support.