This review aims to understand the co-existence of mental ill-health and heart failure and if this comorbidity affects patient self-care motivation and overall health outcomes. Databases searched were; PubMed®, Google® scholar and Science Direct® for studies related to heart failure, heart failure and mental health, depression and anxiety. Eleven articles were identified and reviewed. There were two studies disagreed with the theory that the mental ill-health and heart failure has disease modification and worsen patient health outcomes, three studies concluded that only anxiety has effect, five studies concluded that both anxiety and depression have effect, six studies concluded that depression only has effect but all eleven stated that more research is required. Recent theories on depression and cardiovascular disease comorbidity and the effect mental ill-health have on medication adherence in heart failure patients was discussed. People with long-term physical illnesses may suffer further complications to their health if they develop mental illness; increasing the cost of their care by an average of 45%, however, in the majority of these cases, the mental issues neither diagnosed nor treated. This review explored the link between cardiovascular disease (CVD) and mental ill health; and how comorbidity of the two conditions affects patients' adherence to therapy behaviour. It was concluded that while the link between mental ill health and heart failure (HF) is recognized, studies that may be used as a basis of evidence to confirm this link are scarce.