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Abstract

OBJECTIVE: This study investigated whether cancer patients with and without major depression exhibit immune system abnormalities similar to those reported in medically healthy, depressed subjects without cancer. METHOD: The study subjects consisted of patients diagnosed with pancreatic, esophageal, or breast cancer. Other groups consisted of subjects with major depression (without cancer) and healthy comparison subjects. Subjects’ diagnoses were made with the Structured Clinical Interview for DSM-III-R. Severity of depression was measured with the Hamilton Depression Rating Scale. Plasma concentrations of interleukin-6 (IL-6) and postdexamethasone cortisol were measured. RESULTS: Cancer patients with depression had markedly higher plasma concentrations of IL-6 than healthy comparison subjects and cancer patients without depression. Although significant correlations were found between Hamilton depression scale scores and plasma concentrations of postdexamethasone cortisol, no significant correlations were found between plasma IL-6 and postdexamethasone cortisol concentrations. CONCLUSIONS: Higher than normal plasma IL-6 concentrations were associated with a diagnosis of major depression in cancer patients. IL-6 may contribute to sickness behavior that has overlapping symptoms with major depression.
Cancer patients, who experience marked physiologic, economic, and psychological stressors, have long been observed to have elevated prevalence rates of major depression, compared with the general population (1). Among cancer patients, the highest prevalence rates are exhibited by patients with either oropharyngeal cancer (24) or pancreatic cancer (57). Prospective or cross-sectional studies of patients with pancreatic cancer have documented a remarkable point prevalence rate of depression of 50% (58). Although a number of neurochemical, neuroendocrine, neuroanatomical, and neuroimmune alterations have been associated with unipolar depression, few of these psychobiologic alterations have been systematically investigated in cancer patients with depression.
Increasing evidence has suggested that cytokines may play a role in the pathophysiology of mood disorders. Cytokines are intercellular signaling polypeptides produced by activated cells that regulate immune responses, the acute phase reaction, and hematopoiesis and play a central role in host defense (9, 10). Cytokines also communicate information regarding immune activity to the brain and neuroendocrine system (11). This cytokine-mediated “communication” between the immune and neuroendocrine systems (12) is exemplified by the increased pituitary and adrenocortical secretion that occurs in response to infection or inflammation. Indeed, circulating cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF) have the capacity to directly stimulate the hypothalamic-pituitary-adrenal (HPA) axis and the release of corticotropin-releasing factor (CRF) (1113). Of relevance to mood disorders, these cytokines can also induce “sickness behavior,” which includes symptoms of fatigue, anorexia, anhedonia (loss of interest in usual activities), decreased psychomotor activity, and disappearance of body care activities (14, 15). These signs and symptoms accompany the immunologic response to infection and overlap with the symptoms of major depression. As a key regulator of the acute phase response (16, 17), IL-6 has received special attention in a number of studies that have documented higher than normal acute phase reactants in depressed patients (18, 19). Moreover, an increasing body of literature has documented the myriad neurophysiological effects of IL-6, IL-6 expression in human astrocytes and microglia (20), and the region-specific distribution of IL-6 and IL-6 receptor mRNA in rat neurons within the medial preoptic nucleus, hippocampus, striatum, and medial hypothalamus (2125).
To our knowledge, there have been no studies measuring IL-6 and its relation to major depression and HPA axis function in patients with cancer. In an effort to understand the pathophysiology of major depression in patients with cancer, we sought to determine whether cancer patients with comorbid major depression exhibited higher than normal plasma concentrations of the proinflammatory cytokine IL-6 and whether alterations in IL-6 were associated with perturbations of the HPA axis, i.e., a higher than normal level of cortisol in response to dexamethasone administration.

Method

Subjects

Study subjects were recruited among outpatients and inpatients at hospitals affiliated with Emory University and from the community by means of newspaper advertisements or word of mouth. The advertisements sought “cancer patients with and without depression” and “patients with depression.” After the study had been fully explained, 115 potential subjects gave written informed consent and were then screened by office interview for the presence of psychiatric disorders, substance abuse, medical illness, and medication intake. Subjects were excluded if they showed evidence of current alcohol or substance abuse, bipolar disorder (mania, hypomania, or cyclothymia), schizoaffective disorder, or schizophrenia. Subjects were between the ages of 18 and 80, had a Mini-Mental State Examination score of at least 24 (26), and had no untreated endocrine, cardiovascular, hematologic, hepatic, renal, or neurological diseases. Subjects were not receiving any psychotropic medications for treatment of depressive or anxiety symptoms. The normal comparison subjects were without any current or past personal history of psychiatric disorder. The depressed subjects without cancer and the normal comparison subjects were without significant medical illness, on the basis of findings of a physical examination, blood and urine analyses, ECG, and chest X-ray.
Of those screened, 10 healthy comparison subjects, 12 depressed subjects without cancer, and 21 cancer patients completed the study (Table 1). This study was approved by the Emory University Human Investigational Committee, and informed consent was obtained from all subjects.

Procedure

All participants were interviewed with the Structured Clinical Interview for DSM-III-R (SCID) (27) and completed a series of observer-rated and self-rated scales, including dimensional measures of depressive symptoms, the 21-item Hamilton Depression Rating Scale (28), and the Carroll Rating Scale for Depression (29). Further information regarding the mood and behavior of the cancer patients was obtained from family members. Final psychiatric diagnoses were provided by consensus of the research team (a master’s-level nurse, a research coordinator, a fourth-year psychiatry resident, and two board-certified psychiatrists) according to Spitzer’s procedure for longitudinal evaluation of all available data (30).
Plasma IL-6 concentrations were obtained at 4:00 p.m. in all subjects and were measured with enzyme-linked immunosorbent assay by using sets of paired monoclonal antibodies for capture and detection, as suggested by the manufacturer’s protocol (Endogen Laboratories, Cambridge, Mass.). Samples were assayed in duplicate, and IL-6 concentrations were derived from a standard curve comprised of serial dilutions (4.1–400 pg/ml) of purified recombinant human IL-6. Assay sensitivity was <1 pg/ml. The mean inter- and intraassay coefficients of variation were 10.9% and 3.6%, respectively. A subset of study participants (nine of the 10 healthy comparison subjects, 11 of the 12 depressed subjects without cancer, eight of the 13 cancer patients without major depression, and all eight of the cancer patients with comorbid major depression) also underwent a dexamethasone suppression test. The subjects ingested 1 mg of dexamethasone at 11:00 p.m., and blood samples were obtained at 4:00 p.m. the next day. A subject exhibited nonsuppression of cortisol, i.e., had an abnormal dexamethasone suppression test result, if the 4:00 p.m. plasma cortisol concentration was ≥5 ng/ml (3134). Plasma concentrations of cortisol were measured by using radioimmunoassay (GammaCoat, Incstar [now DiaSorin], Stillwater, Minn.). The mean inter- and intraassay coefficients of variation were 8.8% and 6.6%, respectively. All biological samples were assayed by personnel who were blind to the diagnostic identity of the study subjects.

Statistical Analysis

One-way analysis of variance (ANOVA) was performed to determine group differences in age. Results for age were presented as means and standard deviations. Since plasma concentrations of IL-6 and postdexamethasone plasma cortisol concentrations were not normally distributed within the groups, a Kruskal-Wallis one-way ANOVA on ranks was utilized to determine group differences on these two indices. The median IL-6 plasma concentrations and the 95% confidence interval (CI) of the median were also calculated within each group (35). Fisher’s exact test was used to determine between-group differences in postdexamethasone plasma cortisol concentrations. Spearman rank-order correlations were used to determine the relationships among Hamilton depression scale scores, plasma IL-6 concentrations, and postdexamethasone plasma cortisol concentrations.

Results

Demographic and clinical characteristics of the study sample are presented in Table 1. The study groups did not differ significantly in mean age (F=2.76, df=3, 39, p=0.055). However, the cancer patients with comorbid major depression were the eldest group, and the healthy comparison subjects were the youngest group. Hamilton depression scale scores indicating moderate severity of depression were observed in the two study groups with major depression, although the cancer patients without depression exhibited some depressive symptoms.
There was a significant difference in mean plasma concentrations of IL-6 between the four groups (Figure 1). Among the four study groups, the cancer patients with major depression had the highest median plasma concentration of IL-6 (median=116.4 pg/ml, 95% CI=8.6–512.5), and the cancer patients without major depression had the lowest (median=0 pg/ml, 95% CI=0.0–0.0). The median plasma IL-6 concentrations for the depressed comparison group and the healthy comparison group were 50.0 pg/ml (95% CI=11.1–296.0) and 0.1 pg/ml (95% CI=0–2.2), respectively (Figure 1).
Although there were no significant differences in mean plasma cortisol concentrations after dexamethasone administration among the four groups (H=4.7, df=3, p=0.20), analysis of postdexamethasone cortisol suppressor status revealed a significant overall difference among the four groups (p=0.02, Fisher’s exact test). Cancer patients with major depression exhibited the highest rate of postdexamethasone cortisol nonsuppression, compared to the other study groups. Of the eight cancer patients with major depression, five (63%) were nonsuppressors of cortisol (plasma cortisol concentrations ≥5 ng/ml), compared to one (13%) of the eight of the cancer patients without major depression. Moreover, three (27%) of the 11 subjects with major depression without cancer were cortisol nonsuppressors, compared to none of the healthy comparison subjects.
The relationships among Hamilton depression scale scores, postdexamethasone cortisol plasma concentrations, and plasma IL-6 concentrations were also explored. There was a positive correlation between Hamilton depression scale scores and postdexamethasone cortisol plasma concentrations (rs=0.35, df=30, p=0.05). The correlation between the Hamilton depression scale scores and postdexamethasone cortisol plasma concentrations was also evaluated within two subgroups: the depressed subjects (including subjects with depression alone and cancer patients with major depression) and the nondepressed subjects (including normal comparison subjects and cancer patients without major depression). The correlations were not significant (depressed: rs=0.36, df=15, p=0.16; nondepressed: rs=0.33, df=13, p=0.23). There were no significant correlations between Hamilton depression scale scores and plasma IL-6 concentrations (rs=0.24, df=37, p=0.14) or between plasma IL-6 concentrations and postdexamethasone cortisol concentrations (rs=–0.10, df=34, p=0.55).

Discussion

In this preliminary study of 21 patients with cancer, cancer patients with depression exhibited significantly higher plasma concentrations of IL-6, compared to cancer patents without depression and healthy comparison subjects. These higher levels of IL-6 were similar to levels observed in depressed subjects without cancer and are consistent with reports in the literature describing higher than normal IL-6 plasma concentrations in patients with major depression (18, 3639). Indeed, proinflammatory cytokines such as IL-6 have the capacity to induce a syndrome of “sickness-behavior” that shares many features with major depression, including anhedonia, fatigue, anorexia, reduced activity, and altered sleep patterns (14, 15). IL-6 is also an important mediator of the acute phase response, and higher than normal levels of acute phase proteins have been reported in depressed patients by our group and others (18, 19). Nevertheless, the high levels of IL-6 in cancer patients with depression may reflect an epiphenomenon of the cancer disease process, rather than play a primary causal role in the pathophysiology of major depression in patients with cancer. However, if IL-6 plays a direct role in inducing major depression, cancer patients may be especially vulnerable to the behavioral and neuroendocrine consequences of IL-6 and other proinflammatory cytokines, including IL-1 and TNF, by virtue of immune activation secondary to tissue destruction and the associated inflammation. Such a scenario would suggest that patients with medical disorders (and associated inflammation) other than cancer also may be at risk for depression by virtue of increased peripheral release of proinflammatory cytokines, which in turn have central nervous system effects.
A major pathway by which IL-6 and other proinflammatory cytokines are regulated is the HPA axis. Glucocorticoids, the final product of HPA-axis activation, are potent inhibitors of cytokine activity and inflammatory responses (40). Besides increased release, another mechanism that may contribute to higher than normal IL-6 in medically ill patients with depression is disruption of glucocorticoid-mediated feedback inhibition of cytokine production. Disruption of glucocorticoid-mediated feedback pathways is evidenced by postdexamethasone nonsuppression of cortisol. In this study, subjects with cancer and major depression exhibited a high rate of postdexamethasone cortisol nonsuppression (63%). In addition, the positive correlation between Hamilton depression scale scores and postdexamethasone cortisol plasma concentrations confirms and extends a large body of literature documenting the relationship between severity of major depression and alterations in glucocorticoid-mediated feedback inhibition (41). Nevertheless, patients with certain types of cancers, i.e., cancers of the pancreas and/or gastroesophageal tract, may be more prone to postdexamethasone cortisol nonsuppression, irrespective of depression. For example, Joffe and colleagues (7) reported that all of six patients with pancreatic cancer were cortisol nonsuppressors, even though only one of the six had a diagnosis of major depression. Moreover, five of six patients with gastric cancer were cortisol nonsuppressors, even though none of the gastric cancer patients was diagnosed with major depression. In this study, all of the four patients with pancreatic cancer and comorbid depression were cortisol nonsuppressors. However, only one of the four patients with pancreatic cancer without comorbid depression were cortisol nonsuppressors. Our results are consistent with those of Evans et al. (42), who found that 11% of women with gynecologic cancers without psychiatric diagnoses exhibited postdexamethasone cortisol nonsuppression, compared to 40% of those with comorbid major depression. It should be noted that proinflammatory cytokines themselves can disrupt glucocorticoid-mediated negative feedback pathways through direct effects on the glucocorticoid receptor (43). Although a relationship between IL-6 and postdexamethasone cortisol concentrations in depressed patients has been reported (44), no correlation was found between these two variables in this study. The small size of the study groups and wide variations in plasma cytokine concentrations may have contributed to these results. Nevertheless, there may be a subpopulation of depressed patients with elevated IL-6 who exhibit postdexamethasone nonsuppression of cortisol.
The psychological distress and dysphoria observed in some patients with cancer represent complex interactions of social, psychological, and biological factors. The data presented herein indicate that one potential source of this distress may be IL-6, which is capable of exerting direct effects on CNS function leading to behavioral symptoms consistent with those seen in major depression. Future studies are warranted to elucidate the role of IL-6 in mood disorder in patients with cancer and/or other medical illnesses with associated immune activation.
TABLE 1
Figure 1. Plasma Interleukin-6 (IL-6) Concentrations of Healthy Comparison Subjects, Comparison Subjects With Major Depression, and Cancer Patients With and Without Major Depressiona
aPlasma IL-6 concentrations were measured at 4:00 p.m.
bSignificant difference among groups (H=13.9, df=3, p=0.003).

Footnote

Received June 12, 2000; revision received Jan. 5, 2001; accepted Jan. 11, 2001. From the Department of Psychiatry and Behavioral Sciences and the Winship Cancer Institute, Emory University School of Medicine; the Department of Psychology, University of Virginia School of Medicine, Charlottesville, Va.; and the Department of Biostatistics, Rollins School of Public Health, Emory University, Atlanta. Address reprint requests to Dr. Nemeroff, Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, 1639 Pierce Dr., Suite 4000, Atlanta, GA 30322; [email protected] (e-mail). Supported by NIMH grants MH-49523, MH-01399, and MH-00680 and grant DK-07298 from the National Institute of Diabetes and Digestive and Kidney Diseases. The authors thank the study participants; the physicians, physician assistants, and nursing staff of the Divisions of Medical Oncology, Radiation Oncology, and Surgical Oncology of Emory University School of Medicine; the Winship Cancer Institute; and the Division of Radiation Oncology at Grady Memorial Hospital for assistance with this study.

References

1.
McDaniel JS, Musselman DL, Porter MR, Reed DA, Nemeroff CB: Depression in the cancer patient: a commentary on diagnosis, biology, and treatment. Arch Gen Psychiatry 1995; 52:89-99
2.
Morton RP, Davies ADM, Baker J, Baker GA, Stell PM: Quality of life in treated head and neck cancer patients: a preliminary report. Clin Otolaryngol 1984; 9:181-185
3.
Davies ADM, Davies C, Delpo MC: Depression and anxiety in patients undergoing diagnostic investigations for head and neck cancers. Br J Psychiatry 1986; 149:491-493
4.
Baile WF, Bilbertini M, Scoee L, Endicott J: Depression and tumor stage in cancer of the head and neck. Psychooncology 1992; 1:15-24
5.
Fras I, Litin EM, Pearson JS: Comparison of psychiatric symptoms in carcinoma of the pancreas with those in some other intra-abdominal neoplasms. Am J Psychiatry 1967; 12:1553-1562
6.
Holland JC, Korzun AH, Tross S, Silberfarb P, Perry M, Comis R, Oster M: Comparative psychological disturbance in patients with pancreatic and gastric cancer. Am J Psychiatry 1986; 143:982-986
7.
Joffe RT, Rubinow DR, Denicoff KD: Depression and carcinoma of the pancreas. Gen Hosp Psychiatry 1986; 8:241-245
8.
McDaniel JS, Musselman DL, Nemeroff CB: Psychological distress and depression, in Clinical Oncology, 2nd ed. Edited by Abeloff MD, Armitage JO, Lichter AS, Niederhuber JE. New York, Churchill Livingstone, 1998, pp 556-578
9.
Hirano T, Akira S, Taga T, Kishimoto T: Biological and clinical aspects of interleukin-6. Immunol Today 1990; 170:443-449
10.
Gabay C, Kushner I: Acute-phase proteins and other systemic responses to inflammation. N Engl J Med 1999; 340:448-454
11.
Reichlin S: Neuroendocrine-immune interactions. N Engl J Med 1993; 329:1246-1253
12.
Blalock JE: A molecular basis for bidirectional communication between the immune and neuroendocrine systems. Physiol Rev 1989; 69:1-32
13.
Besedovsky HO, del Rey A: Immune-neuro-endocrine interactions: facts and hypotheses. Endocr Rev 1996; 17:64-102
14.
Kent S, Bluthe RM, Kelley KW, Dantzer R: Sickness behavior as a new target for drug development. Trends Pharmacol Sci 1992; 13:24-28
15.
Yirmiya R: Endotoxin produces a depressive-like episode in rats. Brain Res 1996; 711:163-174
16.
Heinrich PC, Castell JV, Andus T: Interleukin-6 and the acute phase response. Biochem J 1990; 265:621-636
17.
Green AI, Austin CP: Psychopathology of pancreatic cancer: a psychobiologic probe. Psychosomatics 1993; 34:208-221
18.
Sluzewska A, Rybakowski J, Bosmans E, Sobieska M, Berghmans R, Maes M, Wiktorowicz K: Indicators of immune activation in major depression. Psychiatry Res 1996; 64:161-167
19.
Nemeroff CB, Krishnan KR, Blazer DG, Knight DL, Benjamin D, Meyerson LR: Elevated plasma concentrations of alpha 1-acid glycoprotein, a putative endogenous inhibitor of the tritiated imipramine binding site, in depressed patients. Arch Gen Psychiatry 1990; 47:337-340
20.
Lafortune L, Nalbantoglu J, Antel JP: Expression of tumor necrosis factor alpha (TNF alpha) and interleukin 6 (IL-6) mRNA in adult human astrocytes: comparison with adult microglia and fetal astrocytes. J Neuropathol Exp Neurol 1996; 55:515-521
21.
Yan HQ, Banos MA, Herregodts P, Hooghe R, Hooghe-Peters EL: Expression of interleukin (IL)-1 beta, IL6 and their respective receptors in the normal rat brain and after injury. Eur J Immunol 1992; 22:2963-2971
22.
Gadient RA, Otten U: Differential expression of interleukin-6 (IL-6) and interleukin-6 receptor (IL-6R) messenger RNAs in rat hypothalamus. Neurosci Lett 1993; 153:13-16
23.
Schobitz B, de Kloet ER, Sutanto W, Holsboer F: Cellular localization of interleukin 6 mRNA and interleukin 6 receptor mRNA in rat brain. Eur J Neurosci 1993; 5:1426-1435
24.
Schobitz B, Voorhuis DAM, De Kloet ER: Localization of interleukin 6 mRNA and interleukin 6 receptor mRNA in rat brain. Neurosci Lett 1992; 136:189-192
25.
Sebire G, Emilie D, Wallon C, Hery C, Devergne O, Delfraissy J-F, Galanaud P, Tardieu M: In vitro production of IL-6, IL-1b, and tumor necrosis factor-alpha by human embryonic microglial and neural cells. J Immunol 1993; 150:1517-1523
26.
Folstein MF, Folstein SE, McHugh PR: “Mini-Mental State”: a practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975; 12:189-198
27.
Spitzer RL, Williams JBW, Gibbon M: Structured Clinical Interview for DSM-III-R (SCID). New York, New York State Psychiatric Institute, Biometrics Research, 1987
28.
Hamilton M: A rating scale for depression. J Neurol Neurosurg Psychiatry 1960; 23:56-62
29.
Carroll BJ, Feinberg M, Smouse PE, Rawson SG, Greden JF: The Carroll Rating Scale for Depression, I: development, reliability and validation. Br J Psychiatry 1981; 138:194-200
30.
Spitzer RL: Psychiatric diagnosis: are clinicians still necessary? Compr Psychiatry 1983; 24:399-341
31.
Carroll BJ: The dexamethasone suppression test for melancholia. Br J Psychiatry 1982; 140:292-304
32.
Green HS, Kane JM: The dexamethasone suppression test in depression. Clin Neuropharmacol 1983; 6:7-24
33.
Arana GW, Baldessarini RJ, Ornsteen M: The dexamethasone suppression test for diagnosis and prognosis in psychiatry. Arch Gen Psychiatry 1985; 42:1193-1204
34.
APA Task Force on Laboratory Tests in Psychiatry: The dexamethasone suppression test: an overview of its current status in psychiatry. Am J Psychiatry 1987; 144:1253-1262
35.
Rao PV: Inferences about one or two populations: ordinal data, in Statistical Research Methods in the Life Sciences. Pacific Grove, Calif, Brooks/Cole, 1998
36.
Maes M, Meltzer HY, Bosmans E, Bergmans R, Vandoolaeghe E, Ranjan R, Desnyder R: Increased plasma concentrations of interleukin-6, soluble interleukin-6, soluble interleukin-2 and transferrin receptor in major depression. J Affect Disord 1995; 34:301-309
37.
Lanquillon S, Krieg J-C, Bening-Abu-Shach U, Vedder H.: Cytokine production and treatment response in major depressive disorder. Neuropsychopharmacology 2000; 22:370-379
38.
Maes M, Bosmans E, DeJongh R, Kenis G, Vandoolaeghe E, Neels H: Increased serum IL-6 and IL-1 receptor antagonist concentrations in major depression and treatment resistant depression. Cytokine 1997; 9:853-858
39.
Frommberger UH, Bauer J, Haselbauer P, Fraulin A, Riemann D, Berger M: Interleukin-6-(IL-6) plasma levels in depression and schizophrenia: comparison between the acute state and after remission. Eur Arch Psychiatry Clin Neurosci 1977; 247:228-233
40.
Chrousos GP: The hypothalamic-pituitary-adrenal axis and immune-mediated inflammation. N Engl J Med 1995; 332:1351-1362
41.
Musselman DL, DiBattistia C, Nathan KI, Kilts CD, Schatzberg AF, Nemeroff CB: Biology of mood disorders, in American Psychiatric Press Textbook of Psychopharmacology, 2nd ed. Edited by Schatzberg AF, Nemeroff CB. Washington, DC, American Psychiatric Press, 1998, pp 550-588
42.
Evans DL, McCartney CF, Nemeroff CB, Raft D, Quade D, Golden RN, Haggerty JJ Jr, Holmes V, Simon JS, Droba M: Depression in women treated for gynecological cancer: clinical and neuroendocrine assessment. Am J Psychiatry 1986; 143:447-452
43.
Pariante CM, Pearce BD, Pisell TL, Sanchez CI, Po C, Su C, Miller AH: The proinflammatory cytokine, interleukin-1 alpha, reduces glucocorticoid receptor translocation and function. Endocrinology 1999; 140:4359-4366
44.
Maes M, Scharpe S, Meltzer HY, Bosmans E, Suy E, Calabrese J, Cosyns P: Relationships between interleukin-6 activity, acute phase proteins, and function of the hypothalamic-pituitary-adrenal axis in severe depression. Psychiatry Res 1993; 49:11-27

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Published In

Go to American Journal of Psychiatry
Go to American Journal of Psychiatry
American Journal of Psychiatry
Pages: 1252 - 1257
PubMed: 11481159

History

Published online: 1 August 2001
Published in print: August 2001

Authors

Affiliations

Dominique L. Musselman, M.D.
Andrew H. Miller, M.D.
Maryfrances R. Porter, B.A.
Amita Manatunga, Ph.D.
J. Stephen McDaniel, M.D.
Charles B. Nemeroff, M.D., Ph.D.

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