Biological psychology
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Biological psychology · Apr 2013
Longitudinal associations in adolescence between cortisol and persistent aggressive or rule-breaking behavior.
Although several studies have associated antisocial behavior with decreased cortisol awakening responses (CAR), studies in adolescent samples yielded inconsistent results. In adolescence however, the CAR develops and antisocial behavior is heterogeneous in type and persistence. Therefore this longitudinal study compared persistent aggressive and rule-breaking adolescents to low aggressive and rule-breaking adolescents on the development of the CAR from ages 15 to 17 (N=390). ⋯ No differences between adolescents showing persistent high rule-breaking and low rule-breaking were found. This longitudinal study is the first to show that persistent aggression, but not rule-breaking behavior, is related to neurobiological alterations. Moreover, despite development of the CAR over adolescence, the decrease in cortisol is consistent over time in persistent high aggressive adolescents, which is an important prerequisite for the prediction of persistent aggression.
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Biological psychology · Apr 2013
Dysregulated diurnal cortisol pattern is associated with glucocorticoid resistance in women with major depressive disorder.
Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis is believed to play a role in the pathophysiology of depression. To investigate mechanisms that may underlie this effect, we examined several indices of HPA axis function - specifically, diurnal cortisol slope, cortisol awakening response, and suppression of cortisol release following dexamethasone administration - in 26 pre-menopausal depressed women and 23 never depressed women who were matched for age and body mass index. Salivary cortisol samples were collected at waking, 30 min after waking, and at bedtime over three consecutive days. ⋯ Finally, greater self-reported depression severity was associated with flatter diurnal cortisol slopes and with less dexamethasone-related cortisol suppression for depressed women. Depression in women thus appears to be characterized by altered HPA axis functioning, as indexed by flatter diurnal cortisol slopes and an associated impaired sensitivity of cortisol to dexamethasone. Given that altered HPA axis functioning has been implicated in several somatic conditions, the present findings may be relevant for understanding the pathophysiology of both depression and depression-related physical disease.
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Biological psychology · Apr 2013
Approaching dysphoric mood: state-effects of mindfulness meditation on frontal brain asymmetry.
Meditation-based interventions reduce the relapse risk in recurrently depressed patients. Randomized trials utilizing neurophysiologic outcome measures, however, have yielded inconsistent results with regard to a prophylactic effect. Although frontal brain asymmetry, assessed through electroencephalographic (EEG) alpha activity (8-13 Hz), is indicative of approach vs. withdrawal-related response dispositions and represents a vulnerability marker of depression, clinical trials have provided mixed results as to whether meditation has beneficial effects on alpha asymmetry. ⋯ In a "rumination challenge group", EEG was obtained during the same resting conditions, whereas in the active period, initial meditation instructions were followed by a rumination challenge. A significant shift in mid-frontal asymmetry, yielding a pattern indicative of approach motivation, was observed in the mindfulness support group, specifically during the meditation period. This indicates that mindfulness meditation may have a transient beneficial effect, which enables patients to take an approach-related motivational stance, particularly under circumstances of risk.