No abstract

Narrowly defined, AIM appears to be at greatest risk for bipolar I patients. Our haplotype analysis of SLC6A4 suggests that future pharmacogenetic studies should not only focus on the SLC6A4 promotor variation but also investigate the role of other variants in the gene.

Do perfectionists try harder? Previous research on perfectionism and effort has used self-report items and task performance as indicators of effort. The current study investigated whether individual differences in perfectionism predicted effort-related cardiac activity during a mental effort task. Based on past research that suggests adaptive perfectionism is associated with higher effort, it was hypothesized that self-oriented perfectionism (SOP) would predict increased effort on the task. One hundred and eleven college students completed the Multidimensional Perfectionism Scale (MPS) and a self-paced parity task in which they received a small cash reward (3 cents) for each correct response. Impedance cardiography was used to assess autonomic reactivity, and regression models tested whether SOP and socially prescribed perfectionism (SPP) explained autonomic reactivity. Overall, participants showed both sympathetic (faster pre-ejection period; PEP) and parasympathetic activation (elevated high-frequency heart rate variability; HRV) during the task, reflecting higher effort and engagement. Contrary to predictions, individual differences in perfectionism did not moderate cardiac reactivity. These findings draw attention to the importance of assessing physiological components of effort and motivation directly rather than inferring them from task performance or self-reported effort.

Research on depression and effort has suggested “depressive blunting”—lower cardiovascular reactivity in response to challenges and stressors. Many studies, however, find null effects or higher reactivity. The present research draws upon motivational intensity theory, a broad model of effort that predicts cases in which depressive symptoms should increase or decrease effort. Because depressive symptoms can influence task-difficulty appraisals—people see tasks as subjectively harder—people high in depressive symptoms should engage higher effort at objectively easier levels of difficulty but also quit sooner. A sample of adults completed a mental effort challenge with four levels of difficulty, from very easy to difficult-but-feasible. Depressive symptoms were assessed with the CESD and DASS; effort-related cardiac activity was assessed via markers of contractility (e.g., the cardiac pre-ejection period [PEP]) obtained with impedance cardiography. The findings supported the theory’s predictions. When the task was relatively easier, people high in depressive symptoms showed higher contractility (shorter PEP), consistent with greater effort. When the task was relatively harder, people high in depressive symptoms showed diminished contractility, consistent with quitting. The results suggest that past research has been observing a small part of a larger trajectory of trying and quitting, and they illustrate the value of a theoretically grounded analysis of depressive symptoms and effort-related cardiac activity.

Deficits in self-regulation and motivation are central to depression. Using motivational intensity theory (Brehm & Self, 1989), the present research examined how depressive anhedonia influences effort during a piece-rate appetitive task. In piece-rate tasks, people can work at their own pace and are rewarded for each correct response, so they can gain rewards more quickly by expending more effort. A sample of community adults (n = 78) was evaluated for depressive anhedonia using a structured clinical interview, yielding depressive anhedonia and control groups. Participants completed a self-paced cognitive task, and each correct response yielded a cash reward (3 cents or 15 cents, manipulated within-person). Using impedance cardiography, effort-related physiological activity was assessed via the cardiac pre-ejection period (PEP). The results indicated lower reward responsiveness in the anhedonia group. Compared to the control group, the depressive anhedonia group showed significantly less baseline-to-task change in PEP, and they performed marginally worse on the task. The experiment supports the predictions made by applying motivational intensity theory to depression and offers a useful paradigm for evaluating anhedonic effects on effort while people are striving for appealing rewards.