Huntingtin gene repeat size variations affect risk of lifetime depression

Huntington disease (HD) is a severe neuropsychiatric disorder caused by a cytosine-adenine-guanine (CAG) repeat expansion in the HTT gene. Although HD is frequently complicated by depression, it is still unknown to what extent common HTT CAG repeat size variations in the normal range could affect depression risk in the general population. Using binary logistic regression, we assessed the association between HTT CAG repeat size and depression risk in two well-characterized Dutch cohorts─the Netherlands Study of Depression and Anxiety and the Netherlands Study of Depression in Older Persons─including 2165 depressed and 1058 non-depressed persons. In both cohorts, separately as well as combined, there was a significant non-linear association between the risk of lifetime depression and HTT CAG repeat size in which both relatively short and relatively large alleles were associated with an increased risk of depression (β = −0.292 and β = 0.006 for the linear and the quadratic term, respectively; both P < 0.01 after adjustment for the effects of sex, age, and education level). The odds of lifetime depression were lowest in persons with a HTT CAG repeat size of 21 (odds ratio: 0.71, 95% confidence interval: 0.52 to 0.98) compared to the average odds in the total cohort. In conclusion, lifetime depression risk was higher with both relatively short and relatively large HTT CAG repeat sizes in the normal range. Our study provides important proof-of-principle that repeat polymorphisms can act as hitherto unappreciated but complex genetic modifiers of depression

The course of depressive symptoms in unipolar depressive disorder during electroconvulsive therapy: A latent class analysis

Background: Research examining the course of depressive symptoms during electroconvulsive therapy (ECT) is relatively scarce. Objective: To classify patients according to the course of their depressive symptoms while receiving ECT. Methods: The sample consisted of 156 consecutive patients receiving ECT for unipolar depressive disorder. Depressive symptoms were measured weekly with the Montgomery-Asberg Depression Rating Scale. Latent class analysis was applied to identify distinct trajectories of symptom improvement. Results: We identified five classes of different trajectories (improvement rates) of depressive symptoms, i.e. fast improvement (39 patients), intermediate improvement (47 patients), slow improvement (30 patients), slow improvement with delayed onset (18 patients), and finally a trajectory with no improvement (20 patients). The course of depressive symptoms at the end of the treatment within the trajectories of intermediate improvement, slow improvement and slow improvement with delayed onset, was still improving and did not achieve a plateau. Conclusion: The different courses of depressive symptoms during ECT probably contribute to mixed results of prediction studies of ECT outcome. Data suggest that for a large group of patients no optimal clinical endpoint can be identified, other than full remission or no improvement at all, to discontinue ECT. (C) 2009 Elsevier B.V. All rights reserved