The pure investment form of Grossman’s seminal demand-for-health model proposes that people invest in health to raise productivity and earnings; thus there would be little point to investing in one’s health postretirement, and the health stock is predicted to experience a sharp decline. Yet, as Grossman also points out, health has consumptive aspects. One has an incentive to invest in one’s health even postretirement because, as economists would say, health directly enters the utility function. Put more simply, it makes one happy to be healthy. So perhaps retirees have a reason to care about their health after all, although the net effect on health may depend on which effect dominates. In the absence of unambiguous theoretical predictions, the question of whether retirement has an adverse effect on mental and physical health remains an empirical one, and one that several studies have recently attempted to address. The question has important policy implications as we witness a trend toward earlier retirement in most developed nations, along with rising life expectancy and higher health care costs. In this issue of EPIDEMIOLOGY, Oksanen and colleagues carefully analyze the effect of retirement on mental health as measured by antidepressant use 4 years before and 4 years after retirement among a longitudinal cohort of Finnish employees. Finland had a low average retirement age of 59 years in 2004. However, the Finnish Pension Reform of 2005 made the retirement age more flexible and encouraged postponing retirement, with the increase in labor supply purported to lead to beneficial welfare effects. Oksanen et al suggest otherwise, at least with respect to mental health. Accounting for timeinvariant factors such as socioeconomic status, sex, geographic area, and type of employer, and analyzing those who retired due to poor mental or physical health separately, the authors find some evidence that retirement may be beneficial for mental health. They also conclude that those who retired due to mental health issues showed postretirement improvements, in that they reported less antidepressant drug use. Diabetes medications, presumed not to be directly influenced by retirement, are used as a counterfactual. (No effects are found for diabetes drugs, as expected.) The literature on this issue has been fragmented. In another study from Finland, Salokangas and Joukamaa also noted mental health improvements among retirees, but no clear effect on physical health. In contrast, Szinovacz and Davey found that depressive symptoms increases in women after retirement, especially if retirement is perceived as abrupt or forced. The effect is reinforced by the presence of a spouse with functional limitations. Oksanen and colleagues acknowledge that “the reasons for the se inconsistencies ... may be due to differences in study design.” For one thing, the ways health is measured can lead to vast differences in results. Although the use of a more objective measure such as prescription drug use in the Oksanen study may bypass some misreporting issues, there are nonetheless concerns with this measure, particularly as a proxy for underlying mental health, for which reported measures (such as the DSM-III and CESD scales of depression)