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Objective Neurotrophins (NT) are a family of closely related proteins, including brain-derived neurotrophic factor, nerve growth factor, neurotrophin-3 (NT-3), and neurotrophin-4/5 (NT-4/5). NTs are deemed to regulate several aspects of neuronal survival, development, and function. Although NTs have been associated to a variety of mental disorders, the potential role of NT alterations in hypochondriasis (HC) has never been investigated. Methods In the present study, plasma concentrations of NTs were evaluated in 23 adult patients meeting Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria for HC and 22 healthy controls. Platelet serotonin (5-HT) content was chosen as a measure of serotonergic function. Hypochondriacal symptoms were assessed using the Whiteley Index of Hypochondriasis (WIH). Results Plasma NT-3 level ( P =.004) and platelet 5-HT ( P =.008) were significantly lower in patients with HC compared with controls. Correlation analyses showed that the WIH score was significantly and inversely associated with both NT-3 values ( r =−.60, P =.002) and platelet serotonin content ( r =−.53, P =.009). We used a multivariate regression model to determine independent predictors of the WIH score. After allowance for potential confounders, plasma NT-3 levels remained the unique independent predictor of the WIH ( β =.003, t =−3.5, P =.003). Conclusions Decreased NT-3 concentration, alongside with serotonin dysfunction, may represent a biological correlate of HC.

Objective High levels of neuroticism and low self-esteem are markers for vulnerability to depression, a condition associated with a higher risk of arrhythmias. The question as to whether these depression-related personality domains are related to cardiac repolarization (duration of QT interval) in apparently healthy men has been addressed in this study. Methods Participants were 658 clinically healthy males who underwent a health screening programme. QT interval duration was determined in the resting 12-lead electrocardiogram using an automated analysis program. Neuroticism was assessed by the short-scale Eysenck Personality Questionnaire and self-esteem by the Rosenberg self-esteem scale. Results Heart-rate corrected QT interval {QTc, formula of Bazett [Bazett HC. An analysis of time relations of electrocardiograms. Heart 1920;7:353–370]} progressively increased across quartiles of neuroticism ratings. By contrast, no differences in QTc were observed across different degrees of self-esteem. A multivariate regression analysis showed that neuroticism was a statistically significant, independent predictor of QTc duration. Conclusion After adjustment for potential confounders, neuroticism scores independently predicted QT interval duration in apparently healthy men. These findings highlight the possibility that higher arrhythmic risk could be present not only in patients with clinical depression but also in depression-prone, otherwise healthy individuals.