Keeping an open mind?
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Biological Evolution↗
Biomedical subjects
George Anderson
Publications and source records attributed to George Anderson.
Effects of glucocorticoids on declarative memory function in major depression.
BACKGROUND: Major depression has been associated with hypercortisolemia in a subset of patients with depression. Administration of exogenous cortisol and other glucocorticoids to healthy human subjects has been observed to result in a transient impairment in verbal declarative memory function. The purpose of this study was to assess the effects of the glucocorticoid, dexamethasone, on verbal declarative memory function in patients with untreated unipolar major depressive disorder (MDD). METHODS: Fifty two men and women with (n = 28) and without (n = 24) MDD received placebo or dexamethasone (1 mg and 2 mg on 2 successive days) in a double-blind, randomized fashion. Declarative memory was assessed with paragraph recall at baseline (day 1) and day 3. RESULTS: There was a significant interaction between diagnosis and drug (dexamethasone vs. placebo) on paragraph recall. In the healthy subjects, memory improved from baseline to day 3 with placebo and was unchanged with dexamethasone, whereas in MDD patients memory function showed a pattern of decreasing with placebo and improving with dexamethasone from baseline to day 3. CONCLUSIONS: These findings are consistent with an altered sensitivity of declarative memory function in MDD to regulation by glucocorticoids. Possible explanations of the findings include alterations in glucocorticoid receptors in the hippocampus or other brain regions mediating declarative memory, or differential sensitivity to dexamethasone-induced reductions in cortisol, in patients with MDD.
Adolescent↗
Assessment of the hypothalamic-pituitary-adrenal axis over a 24-hour diurnal period and in response to neuroendocrine challenges in women with and without childhood sexual abuse and posttraumatic stress disorder.
BACKGROUND: Preclinical studies showed that early stress results in long-term alterations in the hypothalamic-pituitary-adrenal (HPA) axis. We performed a comprehensive assessment of the HPA axis in women with and without a history of early childhood sexual abuse and posttraumatic stress disorder (PTSD). METHODS: Fifty-two women with and without a history of early childhood sexual abuse and PTSD underwent a comprehensive assessment of the HPA axis, including measurement of cortisol in plasma every 15 min over a 24-hour period and cortisol and corticotropin (ACTH) following corticotropin-releasing factor (CRF) and ACTH challenge. RESULTS: Abused women with PTSD had lower levels of cortisol during the afternoon hours (12:00-8:00 PM) of a 24-hour period compared with non-PTSD women. Their ACTH response to a CRF challenge was blunted compared with nonabused non-PTSD (but not abused non-PTSD) women. There were no differences in cortisol response to CRF and ACTH challenges between the groups. Increased PTSD symptom levels were associated with low afternoon cortisol levels. CONCLUSIONS: These findings suggest that early abuse is associated with increased CRF drive as evidenced by decreased pituitary sensitivity to CRF, whereas in abuse with PTSD there is a specific hypocortisolemia that is most pronounced in the afternoon hours.
Adrenocorticotropic Hormone↗