Biomedical subjects

David R Gettes

Publications and source records attributed to David R Gettes.

6 recordsLinked to original sources

PubMed2006

Corticosterone modulates auditory gating in mouse.

Previous studies suggest that circulating glucocorticoids may influence the encoding and processing of sensory stimuli. The current study investigated this hypothesis by measuring the generation (amplitude), gating (recovery cycle), and sensitivity (intensity function) of auditory evoked responses in C57BL/6 mice treated with chronic corticosterone (0, 1, 5, 15, or 30 mg/kg/day for 14 days). We found that low-dose corticosterone (5 but not 1 mg/kg/day) enhanced the amplitude and improved gating of evoked potentials without affecting the intensity function. In comparison, higher doses (15 and 30 mg/kg/day) decreased the amplitude and impaired gating of evoked potentials, also without altering the stimulus intensity function. At all doses, lower amplitudes of evoked potentials were significantly correlated with higher circulating corticosterone levels. These data highlight the need to consider serum glucocorticoid levels when assessing human disease states associated with aberrations of information processing such as schizophrenia and depression.

Animals↗

PubMed2005

The role of stress-induced cortisol in the relationship between depression and decreased bone mineral density.

BACKGROUND: This study was designed to test the hypothesis that cortisol mediates the relationship between bone density and depression in postmenopausal women. METHODS: Nineteen women aged 52-79 who had been assessed for bone mineral density by dual-energy x-ray absorptiometer (DEXA) were evaluated for depression and anxiety. Diurnal and stress-induced measures of salivary cortisol were obtained during the following week and at a laboratory session involving a speech task. RESULTS: Nine volunteers reported depression while 10 were never depressed. Ever depressed women had significantly lower total lumbar and right femur DEXA Z scores than never depressed (t(17) = 2.5, p = .019 and t(17) = 2.06, p = .05, respectively). Ever depressed women demonstrated a significant increase in salivary cortisol (area under the curve (AUC) = 27.83, SD = 37.64) compared to never depressed women (AUC = -13.34, SD = 19.55) (t(17) = -3.041, p = .007) during a psychological challenge. There were significant inverse relationships between salivary cortisol AUC values and bone density Z scores at every measured bone site. Mediation analyses suggest that 51 - 67% of the association between depression and bone density could be attributed to stress-induced changes in cortisol. CONCLUSIONS: Cortisol hypersecretion in response to stress may, in part, explain the impact of depression on bone density in post-menopausal women.

Absorptiometry, Photon↗

PubMed2003

Depression and HIV infection: impact on immune function and disease progression.

Can psychological factors, such as depression, affect human immunodeficiency virus progression? HIV infection is viewed as a chronic illness in which those infected often confront a number of emotional challenges and physical health and disease-related issues. Over the past 20 years, there has been increasing evidence that depression and other mood-related disturbances are commonly observed among HIV-positive individuals. There is also mounting data showing that depressive symptoms might further impact upon specific elements of immune system functioning and influence quality of life and health status. This paper will highlight studies examining the prevalence of depression during HIV infection and review some of the evidence examining the impact of depressive symptoms on immune function and HIV disease progression.

CD4 Lymphocyte Count↗

PubMed2003

Neuropsychopharmacologic treatment of depression and other neuropsychiatric disorders in HIV-infected individuals.

How can neuropsychiatric disorders and syndromes be underdiagnosed and inadequately treated in individuals infected with human immunodeficiency virus? Depression in particular is among the most prevalent diagnoses and there is a solid foundation of data from controlled clinical studies that has begun to examine the efficacy of various antidepressants in HIV-infected persons. This article summarizes essential findings pertaining to the use of psychotropic medications to treat depression and other neuropsychiatric disorders in the context of immunodeficiency. This includes discussion of clinically significant treatment considerations (eg, efficacy, side effects, drug-drug interactions) derived from the existing literature. Taken together, there is compelling evidence that psychopharmacologic intervention can improve the quality of life of mentally ill HIV-infected individuals.

AIDS Dementia Complex↗

PubMed2002

Association of depression with viral load, CD8 T lymphocytes, and natural killer cells in women with HIV infection.

OBJECTIVE: Clinical and epidemiology studies have implicated depression as a risk factor in the morbidity and mortality of many human diseases. This study sought to determine if depression was associated with alterations in cellular immunity variables-specifically, natural killer (NK) cells and CD8 T lymphocytes-in women with HIV infection. METHOD: Ninety-three women (63 HIV-seropositive, 30 HIV-seronegative) were studied as part of an ongoing longitudinal study conducted at two sites. Subjects underwent extensive clinical, psychiatric, and immunological evaluations. CBC counts and flow cytometry panels were conducted and NK cell activity assayed for all subjects; viral load was determined for HIV-seropositive subjects. RESULTS: The overall rate of major depression in the HIV-seropositive and HIV-seronegative women was 15.87% (N=10 of 63) and 10.00% (N=3 of 30), respectively. HIV-seropositive women had higher depressive symptom scores than did the comparison subjects (Hamilton depression scale: mean=8.62 [SD=7.26] versus mean=5.67 [SD=7.33], respectively). Both groups had similar anxiety scores. Depressive and anxiety symptoms were significantly associated with higher activated CD8 T lymphocyte counts and higher viral load levels. Major depression was associated with significantly lower natural killer cell activity, and depressive and anxiety symptom scores showed a similar correlation. CONCLUSIONS: Our findings provide the first evidence that depression may alter the function of killer lymphocytes in HIV-infected women and suggest that depression may decrease natural killer cell activity and lead to an increase in activated CD8 T lymphocytes and viral load. The rate of current major depression in these HIV-seropositive women (none of whom had current substance abuse) is approximately twice that reported for HIV-seropositive men. The rate is also consistent with studies of women with other medical illnesses and with a recent epidemiology study that associated depression with mortality in HIV-infected women with chronic depressive symptoms. Depression may have a negative impact on innate immunity. Examination of killer lymphocytes may prove useful in assessing the potential relationship between depression, immunity, and HIV disease progression in women.

Adult↗

PubMed2002

Depressive and anxiety disorders in women with HIV infection.

OBJECTIVE: This study examined whether there were differences in the rate of depressive and anxiety disorders between HIV-infected women (N=93) and a comparison group of uninfected women (N=62). Secondary objectives were to examine correlates of depression in HIV-infected women-including HIV disease stage and protease inhibitor use-and the associations between symptoms of depression or anxiety and other potential predictor variables. METHOD: Subjects underwent extensive semiannual clinical, psychiatric, neuropsychological, and immunological evaluations. Depressive and anxiety disorder diagnoses were assessed by using the Structured Clinical Interview for DSM-IV. Symptoms of depression and anxiety were evaluated with the Hamilton Depression Rating Scale (the 17-item version and a modified 11-item version) and the Hamilton Anxiety Rating Scale, respectively. RESULTS: The rate of current major depressive disorder was four times higher in HIV-seropositive women (19.4%) than in HIV-seronegative women (4.8%). Mean depressive symptom scores on the 17-item Hamilton depression scale also were significantly higher, overall, in the HIV-infected women (mean=8.7, SD=8.0) relative to comparison subjects (mean=3.3, SD=5.8). There was no significant between-group difference in the rate of anxiety disorders. However, HIV-seropositive women had significantly higher anxiety symptom scores (mean=8.8, SD=8.9) than did HIV-seronegative women (mean=3.6, SD=5.5). Both groups had similar substance abuse/dependence histories, but adjusting for this factor had little impact on the relationship of HIV status to current major depressive disorder. CONCLUSIONS: HIV-seropositive women without current substance abuse exhibited a significantly higher rate of major depressive disorder and more symptoms of depression and anxiety than did a group of HIV-seronegative women with similar demographic characteristics. These controlled, clinical findings extend recent epidemiologic findings and underscore the importance of adequate assessment and treatment of depression and anxiety in HIV-infected women.

Adolescent↗