The Selective Serotonin Reuptake Inhibitor Citalopram Decreases Human Immunodeficiency Virus Receptor and Coreceptor Expression in Immune Cells.

BACKGROUND: This study investigated whether the selective serotonin reuptake inhibitor (SSRI) citalopram downregulates the expression of the human immunodeficiency virus (HIV) receptor cluster of differentiation 4 (CD4) and coreceptors chemokine receptor type 5 and chemokine-related receptor type 4 (CCR5 and CXCR4) on peripheral blood mononuclear cells (PBMCs) and macrophages ex vivo as a potential mechanism of reducing susceptibility to HIV infection. METHODS: The sample included 150 participants 18-58 years old (59% women, 65% African American, 61% with depression). Monocyte-depleted PBMCs were treated with phytohemagglutinin for 72 hours and then cultured in the presence of interleukin-2 with vehicle control or the SSRI (10(-6) mol/L) for 2 hours. To generate monocyte-derived macrophages, monocytes were cultured for 7 days, after which either vehicle control or SSRI (10(-6) mol/L) was added for 2 hours. RNA was collected from both cell types, and messenger RNA expression of CD4, CCR5, and CXCR4 was measured by real-time polymerase chain reaction. RESULTS: In PBMCs, SSRI treatment decreased expression of CD4 (p = .009), CCR5 (p = .008), and CXCR4 (p < .0001). In monocyte-derived macrophages, SSRI treatment decreased expression of CD4 (p < .0001) and CXCR4 (p = .0003), but not CCR5 (p = .71). The suppressive effects of the SSRI on receptor expression did not differ as a function of depression diagnosis or depressive symptom severity. CONCLUSIONS: Treatment with the SSRI at a physiologic dose decreased CD4, CCR5, and CXCR4 expression on PBMCs and macrophages ex vivo. These findings suggest that SSRI treatment, independent of depression status, downregulates HIV receptor and coreceptor expression and may reduce susceptibility of immune cells to HIV infection and decrease inflammation. If clinical trials confirm the present findings, ultimately there may be a role for using SSRI treatment adjunctively in HIV and acquired immunodeficiency syndrome.

Influences of hormone replacement therapy on olfactory and cognitive function in postmenopausal women.

Olfactory dysfunction can be an early sign of Alzheimer's disease. Since hormone replacement therapy (HRT) may protect against Alzheimer's disease in postmenopausal women, the question arises as to whether it also protects against olfactory dysfunction in such women. A total of three olfactory and 12 neurocognitive tests were administered to 432 healthy postmenopausal women with varied HRT histories. Serum levels of reproductive hormones were obtained for all subjects; APOE-ε4 haplotype was determined for 77 women. National Adult Reading Test and Odor Memory/Discrimination Test scores were positively influenced by HRT. Odor Identification and Odor Memory/Discrimination Test scores were lower for women who scored poorly on a delayed recall test, a surrogate for mild cognitive impairment. The Wechsler Adult Intelligence Scale, Revised, as a Neuropsychological Instrument Spatial Span Backwards Test scores were higher in women receiving estrogen and progestin HRT and directly correlated with serum testosterone levels, the latter implying a positive effect of testosterone on spatial memory. APOE-ε4 was associated with poorer odor threshold test scores. These data suggest that HRT positively influences a limited number of olfactory and cognitive measures during menopause.

The glucocorticoid antagonist RU-486 suppresses HIV infectivity and replication.

The effects of RU-486, a glucocorticoid antagonist, on HIV infection and replication in depressed and nondepressed women were studied using ex vivo models of HIV infection. RU-486 treatment of cells decreased HIV reverse transcriptase activity of monocyte-derived macrophages in a model of acute infectivity. RU-486 also decreased HIV viral replication in the chronically-infected T-cell line ACH-2, but not in the promonocyte cell line U1. No differences were associated with depression status. Thus, glucocorticoid antagonism may suppress HIV infectivity and replication ex vivo. Studies to determine the role of glucocorticoid antagonists in the host defense against HIV should be performed.

Selective serotonin reuptake inhibitor suppression of HIV infectivity and replication.

OBJECTIVE: To test the hypothesis that the selective serotonin reuptake inhibitor (SSRI) citalopram would down-regulate human immunodeficiency virus (HIV) infectivity and that the greatest effects would be seen in people with depression. Depression is a risk factor for morbidity and mortality in HIV/acquired immune deficiency syndrome. Serotonin (5-HT) neurotransmission has been implicated in the pathobiology of depression, and pharmacologic therapies for depression target this system. The 5-HT transporter and 5-HT receptors are widely distributed throughout the central nervous and immune systems. Depression has been associated with suppression of natural killer cells and CD8(+) lymphocytes, key regulators of HIV infection. METHODS: Ex vivo models for acute and chronic HIV infection were used to study the effects of citalopram on HIV viral infection and replication in 48 depressed and nondepressed women. For both the acute and chronic infection models, HIV reverse transcriptase activity was measured in the citalopram treatment condition and the control condition. RESULTS: The SSRI significantly down-regulated the reverse transcriptase response in both the acute and chronic infection models. Specifically, citalopram significantly decreased the acute HIV infectivity of macrophages. Citalopram also significantly decreased HIV viral replication in the latently infected T-cell line and in the latently infected macrophage cell line. There was no difference in down-regulation by depression status. CONCLUSIONS: These studies suggest that an SSRI enhances natural killer/CD8 noncytolytic HIV suppression in HIV/acquired immune deficiency syndrome and decreases HIV viral infectivity of macrophages, ex vivo, suggesting the need for in vivo studies to determine a potential role for agents targeting serotonin in the host defense against HIV.

Elevated substance P levels in HIV-infected women in comparison to HIV-negative women.

Substance P and its receptor (neurokinin-1R) are potent modulators of neuroimmunoregulation and HIV/AIDS infection. We previously demonstrated that HIV-seropositive men had significantly higher substance P levels compared to uninfected controls. We now demonstrate that substance P plasma levels are significantly higher in HIV-infected women in comparison to uninfected control women.

Selective serotonin reuptake inhibitor and substance P antagonist enhancement of natural killer cell innate immunity in human immunodeficiency virus/acquired immunodeficiency syndrome.

BACKGROUND: Natural killer (NK) cells play an important role in innate immunity and are involved in the host defense against human immunodeficiency virus (HIV) infection. This study examines the potential role of three underlying regulatory systems that have been under investigation in central nervous system research as well as immune and viral research: serotonin, neurokinin, and glucocorticoid systems. METHODS: Fifty-one HIV-seropositive subjects were recruited to achieve a representative sample of depressed and nondepressed women. The effects of a selective serotonin reuptake inhibitor (SSRI), a substance P (SP) antagonist, and a glucocorticoid antagonist on NK cell function were assessed in a series of ex vivo experiments of peripheral blood mononuclear cells from each HIV-seropositive subject. RESULTS: Natural killer cell cytolytic activity was significantly increased by the SSRI citalopram and by the substance P antagonist CP-96345 relative to control conditions; the glucocorticoid antagonist, RU486, showed no effect on NK cytotoxicity. Our results suggest that the effects of the three agents did not differ as a function of depression. CONCLUSIONS: Our findings provide evidence that NK cell function in HIV infection may be enhanced by serotonin reuptake inhibition and by substance P antagonism. It remains to be determined if HIV-related impairment in not only NK cytolytic activity but also NK noncytolytic activity can be improved by an SSRI or an SP antagonist. Clinical studies are warranted to address these questions and the potential roles of serotonergic agents and SP antagonists in improving NK cell immunity, delaying HIV disease progression, and extending survival with HIV infection.

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.

Association of resolution of major depression with increased natural killer cell activity among HIV-seropositive women.

OBJECTIVE: Depression is a potential risk factor for morbidity and mortality among patients with numerous medical conditions, including HIV disease, and it is also associated with decrements in immune function, such as natural killer (NK) cell activity. This study examined whether improvements in the diagnostic status of major depression are related to increases in NK cell activity among HIV-seropositive women. METHOD: HIV-seropositive women were recruited as part of a longitudinal cohort study and underwent comprehensive medical and psychiatric evaluations during a 2-year period. Fifty-seven women had complete NK cell activity and depression data measured at two time points and were examined for associations between changes in depression status and alterations in NK cell activity over time. RESULTS: Among the 57 HIV-seropositive women, improvements in the diagnostic status of depression and decreases in scores on the 17-item Hamilton Depression Rating Scale were significantly associated with increases in NK cell activity over time, as measured in lytic units. Eleven women (19.3%) had a major depression diagnosis that resolved over time, and this group also had a significant increase in cell activity measured in lytic units during this period. CONCLUSIONS: This study suggests that depression may impair certain aspects of innate cellular immunity relevant to delaying the progression of HIV disease and that these alterations are reversible with the resolution of a depressive episode. These findings support an examination of NK cell activity in assessments of the relationship between depression and morbidity and mortality in HIV disease.

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.

Association of depression, CD8+ T lymphocytes, and natural killer cell activity: implications for morbidity and mortality in Human immunodeficiency virus disease.

A heightened risk of mood disorders, such as major depression, and acute depressive symptoms has been observed among HIV-seropositive individuals since the start of the AIDS epidemic, and an accumulating body of data now shows that depression may have an impact on morbidity and mortality among individuals with HIV disease. Although the specific physiologic mechanisms involved in this process have not been delineated, there is some evidence to suggest that certain components of innate immunity, including killer lymphocytes such as CD8+ T lymphocytes and natural killer cells, may represent key pathways through which depression affects HIV disease progression. This paper reviews some of the main studies examining the effects of depression on immunity and HIV disease progression and discusses the potential role of killer lymphocytes as an underlying mechanism by which depression may impact morbidity and mortality.

Prevalence, diagnosis, and pharmacological treatment of mood disorders in HIV disease.

Human immunodeficiency virus seropositive (HIV+) individuals are at a heightened risk of developing mood disorders and related syndromes. Over the past several decades, increased rates of mood disorders, including depression and mania, have been reported among HIV+ individuals. Because alterations in mood may impact on quality of life and perhaps reduce adherence to antiretroviral treatment regimens that are critical for preventing disease progression, recognition and effective treatment of mood disorders is essential. There are accumulating data showing that antidepressants and mood stabilizers, as well as other novel agents, might benefit HIV+ individuals suffering from a concomitant mood disturbance. This review highlights the relevant studies that have examined prevalence rates of mood disorders in HIV+ individuals, characteristics of HIV disease that influence the diagnosis and psychopharmacologic treatment of mood disorders, including complex interactions with antiretroviral medications, as well as the available evidence regarding the efficacy of agents used to treat depression and mania in the context of HIV disease.

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.

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.

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.

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.