Estresse precoce e alterações do eixo hipotálamo-pituitária-adrenal (HPA) na depressão. / Early Life Stress and alterations of the Hypothalamic-Pituitary-Adrenal (HPA) axis in depression.

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

30/03/2012

RESUMO

Introduction: Several studies suggest that stress in early stages of development can induce persistent changes in the ability of the Hypothalamic-Pituitary-Adrenal (HPA) axis to respond to stress in adulthood. The imbalance of cortisol has been identified as a biological correlate of depressive disorders. These abnormalities seem to be related to changes in the ability of circulating glucocorticoids to practice their negative feedback on the secretion of HPA axis hormones through connecting to the mineralocorticoid receptor (MR) and glucocorticoid (GR) in the tissues of HPA axis. Due to the wide variety of stressors, as well as the different subtypes of depression, the findings of current studies have been inconsistent. Thus, more studies need to be able to elucidate the mechanisms involved in the association between Early Life Stress (ELS) and the development of depression. Objective: The objective this study is to evaluate the correlation between of Early Life Stress and changes in Hypothalamic-Pituitary-Adrenal axis and at receptors function glucocorticoid and mineralocorticoid in depressive patients. Methodology: We recruited 30 subjects initially divided into two groups: patients with current depressive episode (n =20) and control group (n = 10) Subsequently, patients were divided into two groups according to the ELS, making the final sample of three groups: depressive patients with ELS (n =13) group of depressive patients without ELS (n=7) and control group (n=10). Patients were evaluated by clinical interview according to the diagnostic criteria of DSM-IV to confirm the diagnosis. To evaluate the severity of depressive symptoms was applied to the Hamilton Depression Scale (HAM-D21), and included only patients with HAM-D21 17. The presence of ELS was confirmed by the Childhood Trauma Questionnaire (CTQ). We also used the Depression Rating Scale Montgomery-Asberg (MADRS), the Beck Depression Inventory (BDI), the Beck Anxiety Inventory (BAI), the Scale for Suicide Ideation Beck (BSI), the Scale Beck Hopelessness (BHS), the Hospital Anxiety and Depression Scale (HADS) and the Barratt Impulsiveness Scale (BIS-11) for the assessment of severity psychiatric symptoms. Endocrine evaluation was placebo-controlled, blinded by the patients and controls, non-randomized design with repeated measures, where the effects of Fludrocortisone (0.5 mg) and dexamethasone (0.5 mg) were assessed using salivary cortisol and plasma. The secretion of plasma cortisol and salivary was evaluated in the subjects, after administration of a capsule of Placebo, Fludrocortisone and Dexamethasone to 22hs the previous day. The salivary cortisol was collected at 22h, on waking, 30 and 60 minutes after waking and before plasma collection in the following days after the challenges. Results: In these sample of depressed patients and controls, we found significantly lower levels of salivary cortisol around waking after administration of Placebo in depressed patients than controls. We also found a trend for patients to have higher levels of salivary cortisol than controls on awakening after administration of Dexamethasone. When measured cortisol after administration of Fludrocortisone, patients showed significantly lower levels of salivary cortisol 30 minutes after waking and the Area Under the Curve (AUC) than controls. In addition, we also found a tendency for depressed patients showed lower levels of salivary cortisol 60 minutes after awakening than controls. When compared between depressed patients with and without ELS and controls, we found a tendency for depressed patients without ELS presented lower levels of salivary cortisol on awakening after Placebo than controls. The mean salivary cortisol levels on waking did not differ between patients with ELS and controls and between patients with and without ELS. The levels of salivary cortisol after Dexamethasone administration between depressed patients with and without ELS and controls, depressed patients without ELS had significantly higher levels of salivary cortisol on awakening than controls. We also found a trend for patients without Early Life Stress have higher levels of salivary cortisol upon waking than patients with Early Life Stress, but there were no significant differences between patients with Early Life Stress and controls. Conclusion: Our data show a hypoactivity of the HPA axis in depressed patients. Moreover, these findings suggest that this dysregulation HPA axis is partly due to a decrease the sensitivity of RG and a hyperactivation of MR in patients depressive. However, when compared depressed patients with and without Early Life Stress, the challenges with selective agonists as the Dexamethasone (agonist GR) and Fludrocortisone (agonist MR) were not able to detect this difference pathophysiological and distinguish between the different types of psychopathology. Thus, these results suggest that studies with a mixed agonist (GR/MR) such as Prednisolone have potential to distinguish of depressive patients with Early Life Stress.

ASSUNTO(S)

cortisol cortisol depressão depression early life stress eixo hipotálamo-pituitária-adrenal estresse precoce glucocorticoid receptors hypothalamic-pituitary-adrenal axis mineralocorticoid receptors. receptores glicocorticóides receptores mineralocorticóides.

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