Stability of chronotype over a 7-year follow-up period and its association with severity of depressive and anxiety symptoms

Background: Chronotype is an individual's preferred timing of sleep and activity, and is often referred to as a later chronotype (or evening-type) or an earlier chronotype (or morning-type). Having an evening chronotype is associated with more severe depressive and anxiety symptoms. Based on these findings it is has been suggested that chronotype is a stable construct associated with vulnerability to develop depressive or anxiety disorders. To examine this, we test the stability of chronotype over 7 years, and its longitudinal association with the change in severity of depressive and anxiety symptoms. Methods: Data of 1,417 participants with a depressive and/or anxiety disorder diagnosis and healthy controls assessed at the 2 and 9-year follow-up waves of the Netherlands Study of depression and anxiety were used. Chronotype was assessed with the Munich chronotype questionnaire. Severity of depressive and anxiety symptoms were assessed with the inventory of depressive symptomatology and Beck anxiety inventory. Results: Chronotype was found to be moderately stable (r = 0.53) and on average advanced (i.e., became earlier) with 10.8 min over 7 years (p <.001). Controlling for possible confounders, a decrease in severity of depressive symptoms was associated with an advance in chronotype (B = 0.008, p =.003). A change in severity of anxiety symptoms was not associated with a change in chronotype. Conclusion: Chronotype was found to be a stable, trait-like construct with only a minor level advance over a period of 7 years. The change in chronotype was associated with a change in severity of depressive, but not anxiety, symptoms

Ernst Freund as Precursor of the Rational Study of Corporate Law

Gindis, David, Ernst Freund as Precursor of the Rational Study of Corporate Law (October 27, 2017). Journal of Institutional Economics, Forthcoming. Available at SSRN: https://ssrn.com/abstract=2905547, doi: https://dx.doi.org/10.2139/ssrn.2905547The rise of large business corporations in the late 19th century compelled many American observers to admit that the nature of the corporation had yet to be understood. Published in this context, Ernst Freund's little-known The Legal Nature of Corporations (1897) was an original attempt to come to terms with a new legal and economic reality. But it can also be described, to paraphrase Oliver Wendell Holmes, as the earliest example of the rational study of corporate law. The paper shows that Freund had the intuitions of an institutional economist, and engaged in what today would be called comparative institutional analysis. Remarkably, his argument that the corporate form secures property against insider defection and against outsiders anticipated recent work on entity shielding and capital lock-in, and can be read as an early contribution to what today would be called the theory of the firm.Peer reviewe

Anxiety sensitivity, its stability and longitudinal association with severity of anxiety symptoms

Anxiety sensitivity is associated with the onset of panic attacks, anxiety, and other common mental disorders. Anxiety sensitivity is usually seen as a relative stable trait. However, previous studies were inconclusive regarding the longitudinal stability of anxiety sensitivity and differed in study designs and outcomes. The current study examines the stability of anxiety sensitivity over time and its longitudinal associations with severity of anxiety symptoms. Participants from the Netherlands Study of Depression and Anxiety with and without an anxiety, depressive, or comorbid anxiety-depressive disorder diagnosis were included (N = 2052). Stability in anxiety sensitivity over two year follow-up and the longitudinal association between the change in anxiety sensitivity and change in severity of anxiety symptoms were tested. Results indicated that two-year stability of anxiety sensitivity was high (r = 0.72), yet this test-retest estimate leaves room for changes in anxiety sensitivity in some individuals as well. Change in anxiety sensitivity was positively associated with change in severity of anxiety symptoms (B = 0.64 in univariable analysis and B = 0.52 in multivariable analysis). The longitudinal association of anxiety sensitivity with severity of anxiety symptoms indicates that targeting anxiety sensitivity may be of additional benefit in clinical practice