Key points(#br)Continuous positive airway pressure (CPAP) adherence is low among individuals with obstructive sleep apnoea.(#br)Type D personality and high scores on the depression and hypochondriasis scales on the Minnesota Multiphasic Personality Inventory (MMPI) have been identified as factors contributing to non-compliance with CPAP.(#br)Further research into personality type may assist in understanding why some people adhere to CPAP, while others fail.(#br)Obstructive sleep apnoea (OSA) is a condition characterised by repetitive, intermittent partial or complete collapse/obstruction of the upper airway during sleep. Continuous positive airway pressure (CPAP) is highly efficacious in treating OSA but its effectiveness is limited due to suboptimal acceptance and adherence rates, with... as many as 50% of OSA patients discontinuing CPAP treatment within the first year. Until recently, research has focused on examining mechanistic and demographic factors that could explain nonadherence ( e.g. age, sex, race and education level) with limited applicability in a prospective or clinical manner.(#br)More recent research has focused on personality factors or types of patients with OSA who comply and do not comply with CPAP adherence in an attempt to enhance the accuracy of predicting treatment compliance. Type D personality has been found to be prevalent in one third of patients with OSA. The presence of Type D personality increases noncompliance and poor treatment outcomes due to negative affectivity, social inhibition, unhealthy lifestyle, and a reluctance to consult and/or follow medical advice. Conversely, individuals who are more likely to adhere to CPAP treatment tend to have a high internal locus of control and high self-efficacy, self-refer for treatment, and have active coping skills. By assessing personality and coping skills, the clinician may gain insight into the likelihood of a patient’s adherence to treatment. If the patient displays potential risk factors for CPAP noncompliance, the clinician can offer the patient education, refer them to a support group, engage in behavioural/motivational therapy and undertake regular follow-up visits or phone calls incorporating troubleshooting to increase CPAP adherence, especially in individuals with Type D personality.