Is There a Relationship between Impulsivity and Depression in Adults? A Research Synthesis

Despite the abundant research on impulsivity and that on depression, and despite several lines of clinical and research evidence pointing out the potential associations between the two phenomena, to date the idea that impulsivity is linked to depression is still seriously questioned. This paper will argue that there is a body of research investigating the relationship between impulsivity and depression. It will argue that this body of research is under-recognized, largely due to the complex, multi-faceted nature of impulsivity, and its varied and inconsistent definitions and measurements used in different studies, resulting in mixed findings. To support these arguments, the paper will first critically review a selected but representative sample of definitions and models of impulsivity across different research disciplines. In so doing, it will highlight the need for an integrated framework for impulsivity, and identify one which suggests three key types of impulsivity: rapid response, preference for immediate reinforcement, and underestimation of risk. Next, results of a systematic search for the extant literature on the relationship between impulsivity and depression will be presented, organized accordingly to the identified integrated framework. A possible theoretical integration of impulsivity research in the context of depression will also be offered, suggesting an operational definition of impulsivity as an action or a behavioural pattern that goes against one's desired goal. The paper will conclude by offering recommendations for future research into the association between depression and the different types of impulsivity, guided by the integrated framework. Important clinical implications will also be discussed.