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Lonhienne TG, Forwood JK, Marfori M, Robin G, Kobe B, Carroll BJ. Importin-beta is a GDP-to-GTP exchange factor of Ran: implications for the mechanism of nuclear import. J Biol Chem 2009; 284:22549-58. [PMID: 19549784 DOI: 10.1074/jbc.m109.019935] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ran-GTP interacts strongly with importin-beta, and this interaction promotes the release of the importin-alpha-nuclear localization signal cargo from importin-beta. Ran-GDP also interacts with importin-beta, but this interaction is 4 orders of magnitude weaker than the Ran-GTP.importin-beta interaction. Here we use the yeast complement of nuclear import proteins to show that the interaction between Ran-GDP and importin-beta promotes the dissociation of GDP from Ran. The release of GDP from the Ran-GDP-importin-beta complex stabilizes the complex, which cannot be dissociated by importin-alpha. Although Ran has a higher affinity for GDP compared with GTP, Ran in complex with importin-beta has a higher affinity for GTP. This feature is responsible for the generation of Ran-GTP from Ran-GDP by importin-beta. Ran-binding protein-1 (RanBP1) activates this reaction by forming a trimeric complex with Ran-GDP and importin-beta. Importin-alpha inhibits the GDP exchange reaction by sequestering importin-beta, whereas RanBP1 restores the GDP nucleotide exchange by importin-beta by forming a tetrameric complex with importin-beta, Ran, and importin-alpha. The exchange is also inhibited by nuclear-transport factor-2 (NTF2). We suggest a mechanism for nuclear import, additional to the established RCC1 (Ran-guanine exchange factor)-dependent pathway that incorporates these results.
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Keenan DM, Roelfsema F, Carroll BJ, Iranmanesh A, Veldhuis JD. Sex defines the age dependence of endogenous ACTH-cortisol dose responsiveness. Am J Physiol Regul Integr Comp Physiol 2009; 297:R515-23. [PMID: 19535673 DOI: 10.1152/ajpregu.00200.2009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sex influences adrenal glucocorticoid responses to ACTH in experimental animals. Whether similar sex differences operate in humans is unknown. To test this notion, we estimated ACTH-cortisol dose-response properties analytically in 48 healthy adults (n = 22 women, n = 26 men), ages 18-77 yr, body mass index (BMI) 18-32 kg/m(2), previously studied at two medical centers. Plasma ACTH and cortisol concentrations were measured every 10 min for 24 h. The 145 sample pairs were used in each subject to estimate ACTH-cortisol drive via a logistic function. Statistical analyses revealed that 24-h cortisol secretion (>82% pulsatile) fell in men (r = -0.38, P = 0.028) and rose in women (r = +0.37, P = 0.045) with age (P = 0.01 sex effect). The mechanisms involved decreased ACTH efficacy with age in men (r = -0.35, P = 0.04), and increased ACTH efficacy with age in women (r = +0.42, P = 0.025) [P = 0.009 sex effect]. ACTH potency diminished with higher BMI in men (r = +0.38, P = 0.029) and in the cohort as a whole (r = 0.34, P = 0.0085). These outcomes demonstrate that sex, age, and BMI modulate selective properties of endogenous ACTH-cortisol drive in humans, thereby indicating the need to control these three major variables in experimental comparisons.
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Cassidy F, Ahearn E, Carroll BJ. Concordance of self-rated and observer-rated dysphoric symptoms in mania. J Affect Disord 2009; 114:294-8. [PMID: 18684512 DOI: 10.1016/j.jad.2008.06.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2008] [Revised: 06/18/2008] [Accepted: 06/24/2008] [Indexed: 10/21/2022]
Abstract
OBJECTIVES High rates of some depressive symptoms occur in both mixed and pure manic episodes. This study examined whether manic subjects identify these depressive symptoms by self-report consistently with observer ratings, whether dysphoric symptoms are self-rated differently in mixed compared to pure manic episodes, and whether discriminative self-rated dysphoric symptom sets agree with those established by observer ratings. METHODS Ninety-four inpatients meeting DSM-IV criteria for mania were classified as in pure or mixed episodes. Dysphoric symptoms were evaluated with the Hamilton Depression Rating Scale (HDRS) and the self-rated Carroll Depression Scale (CDS). Total scores and individual symptom scores on the two scales were compared, as were differences between the manic and mixed subtypes. Positive predictive values (PPV) of individual CDS statements for a diagnosis of a mixed bipolar episode were calculated. Those with a PPV of 0.5 or greater were summed across all subjects and the distributions within the bipolar manic and mixed groups inspected. RESULTS Self-rated depressive symptoms were highly concordant with observer-rated depressive symptoms in mania. Differences were demonstrated between mixed and pure manic subjects based on self-report, and these differences were similar to those observed with HDRS evaluations. A group of 8 dysphoric symptoms discriminated mixed from pure manic episodes on both scales. These symptoms were depressed mood, pathological guilt, suicidal tendency, anhedonia, psychomotor agitation, psychic and somatic anxiety, and general somatic symptoms (fatigue). CONCLUSIONS Manic patients report depressive symptoms consistently with observer ratings. Self-rated dysphoric symptoms differ significantly between mixed and pure manic episodes. Patient self-rating is another tool which may help in the diagnosis of mixed mania and the recognition of depressive symptoms during manic episodes. LIMITATIONS The current study included patients who were evaluated during inpatient hospitalization only. The study included only subjects capable and willing to give written informed consent. Generalizability to other bipolar patients is not established.
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Carroll BJ. Symptoms do not helpfully distinguish unipolar and bipolar depression. Br J Psychiatry 2008; 193:426; author reply 427. [PMID: 18978328 DOI: 10.1192/bjp.193.5.426b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Carroll BJ. Child abuse and adult major depression: no evidence of protective gene. ARCHIVES OF GENERAL PSYCHIATRY 2008; 65:1336-1339. [PMID: 18981346 DOI: 10.1001/archpsyc.65.11.1336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
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Carroll BJ. 'Effects of risperidone augmentation in patients with treatment-resistant depression: results of open-label treatment followed by double-blind continuation'. Neuropsychopharmacology 2008; 33:2546-7; author reply 2548. [PMID: 18033236 DOI: 10.1038/sj.npp.1301613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Carroll BJ. How it really works. BMJ 2008; 337:a788. [PMID: 18632707 PMCID: PMC2483898 DOI: 10.1136/bmj.a788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Paungfoo-Lonhienne C, Lonhienne TGA, Rentsch D, Robinson N, Christie M, Webb RI, Gamage HK, Carroll BJ, Schenk PM, Schmidt S. Plants can use protein as a nitrogen source without assistance from other organisms. Proc Natl Acad Sci U S A 2008; 105:4524-9. [PMID: 18334638 PMCID: PMC2393761 DOI: 10.1073/pnas.0712078105] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Indexed: 11/18/2022] Open
Abstract
Nitrogen is quantitatively the most important nutrient that plants acquire from the soil. It is well established that plant roots take up nitrogen compounds of low molecular mass, including ammonium, nitrate, and amino acids. However, in the soil of natural ecosystems, nitrogen occurs predominantly as proteins. This complex organic form of nitrogen is considered to be not directly available to plants. We examined the long-held view that plants depend on specialized symbioses with fungi (mycorrhizas) to access soil protein and studied the woody heathland plant Hakea actites and the herbaceous model plant Arabidopsis thaliana, which do not form mycorrhizas. We show that both species can use protein as a nitrogen source for growth without assistance from other organisms. We identified two mechanisms by which roots access protein. Roots exude proteolytic enzymes that digest protein at the root surface and possibly in the apoplast of the root cortex. Intact protein also was taken up into root cells most likely via endocytosis. These findings change our view of the spectrum of nitrogen sources that plants can access and challenge the current paradigm that plants rely on microbes and soil fauna for the breakdown of organic matter.
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Carroll BJ, Rubin RT. Mifepristone in psychotic depression? Biol Psychiatry 2008; 63:e1; author reply e3. [PMID: 17919458 DOI: 10.1016/j.biopsych.2007.03.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2006] [Revised: 02/04/2007] [Accepted: 03/02/2007] [Indexed: 10/22/2022]
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Carroll BJ. Regarding "The Munich vulnerability study on affective disorders: premorbid polysomnographic profile of affected high-risk probands". Biol Psychiatry 2007; 62:703; author reply 703-4. [PMID: 17531205 DOI: 10.1016/j.biopsych.2006.12.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2006] [Revised: 12/26/2006] [Accepted: 12/29/2006] [Indexed: 11/22/2022]
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Brosnan CA, Mitter N, Christie M, Smith NA, Waterhouse PM, Carroll BJ. Nuclear gene silencing directs reception of long-distance mRNA silencing in Arabidopsis. Proc Natl Acad Sci U S A 2007; 104:14741-6. [PMID: 17785412 PMCID: PMC1964546 DOI: 10.1073/pnas.0706701104] [Citation(s) in RCA: 171] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2007] [Indexed: 11/18/2022] Open
Abstract
In plants, silencing of mRNA can be transmitted from cell to cell and also over longer distances from roots to shoots. To investigate the long-distance mechanism, WT and mutant shoots were grafted onto roots silenced for an mRNA. We show that three genes involved in a chromatin silencing pathway, NRPD1a encoding RNA polymerase IVa, RNA-dependent RNA polymerase 2 (RDR2), and DICER-like 3 (DCL3), are required for reception of long-distance mRNA silencing in the shoot. A mutant representing a fourth gene in the pathway, argonaute4 (ago4), was also partially compromised in the reception of silencing. This pathway produces 24-nt siRNAs and resulted in decapped RNA, a known substrate for amplification of dsRNA by RDR6. Activation of silencing in grafted shoots depended on RDR6, but no 24-nt siRNAs were detected in mutant rdr6 shoots, indicating that RDR6 also plays a role in initial signal perception. After amplification of decapped transcripts, DCL4 and DCL2 act hierarchically as they do in antiviral resistance to produce 21- and 22-nt siRNAs, respectively, and these guide mRNA degradation. Several dcl genotypes were also tested for their capacity to transmit the mobile silencing signal from the rootstock. dcl1-8 and a dcl2 dcl3 dcl4 triple mutant are compromised in micro-RNA and siRNA biogenesis, respectively, but were unaffected in signal transmission.
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Carroll BJ, Cassidy F, Naftolowitz D, Tatham NE, Wilson WH, Iranmanesh A, Liu PY, Veldhuis JD. Pathophysiology of hypercortisolism in depression. Acta Psychiatr Scand Suppl 2007:90-103. [PMID: 17280575 DOI: 10.1111/j.1600-0447.2007.00967.x] [Citation(s) in RCA: 176] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The mechanisms mediating hypercortisolemia in depression remain controversial. Adopting the biomarker strategy, we studied adrenocorticotropin (ACTH) and cortisol dynamics in hypercortisolemic and non-hypercortisolemic depressed in-patients, and in normal volunteers. METHOD Deconvolution analysis of 24-h pulsatile secretion, approximate entropy (ApEn) estimation of secretory regularity, cross-ApEn quantitation of forward and reverse ACTH-cortisol synchrony, and cosine regression of 24-h rhythmicity. RESULTS Hypercortisolemia was strongly associated with melancholic and psychotic depressive subtypes. Hypercortisolemic patients had elevated ACTH and cortisol secretion, mediated chiefly by increased burst masses. Basal ACTH secretion was increased, ACTH half-life was reduced, and mean 24-h ACTH concentration was normal. Cortisol secretion was increased in a highly irregular pattern (high ApEn), with high ACTH --> cortisol cross-ApEn (impaired feedforward coupling). Cortisol-mediated feedback on the secretory pattern of ACTH was normal. Hypercortisolemic depressed patients had normal programming of the central hypothalamo-pituitary-adrenal (HPA) axis pulse generator: ACTH pulse frequency, cortisol pulse frequency, circadian acrophases, and ApEn of ACTH secretion were normal. Responsiveness of the adrenal cortex to endogenous ACTH was normal. Non-hypercortisolemic patients resembled hypercortisolemic patients on ACTH regulatory parameters but had low total cortisol secretion. CONCLUSION Increased ACTH secretion occurs in depressed in-patients regardless of cortisolemic status, confirming central HPA axis overdrive in severe depression. Depressive hypercortisolemia results from an additional change in the adrenal cortex that causes ACTH-independent, disorderly basal cortisol release, a sign of physiological stress in melancholic/psychotic depression.
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Rubin RT, Carroll BJ. Claims for mifepristone in neuropsychiatric disorders: commentary on DeBattista and Belanoff, and Neigh and Nemeroff. Trends Endocrinol Metab 2006; 17:384-5; author reply 387-9. [PMID: 17070696 DOI: 10.1016/j.tem.2006.10.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Accepted: 10/18/2006] [Indexed: 11/26/2022]
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Fusaro AF, Matthew L, Smith NA, Curtin SJ, Dedic-Hagan J, Ellacott GA, Watson JM, Wang MB, Brosnan C, Carroll BJ, Waterhouse PM. RNA interference-inducing hairpin RNAs in plants act through the viral defence pathway. EMBO Rep 2006; 7:1168-75. [PMID: 17039251 PMCID: PMC1679793 DOI: 10.1038/sj.embor.7400837] [Citation(s) in RCA: 212] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Revised: 09/15/2006] [Accepted: 09/18/2006] [Indexed: 11/09/2022] Open
Abstract
RNA interference (RNAi) is widely used to silence genes in plants and animals. It operates through the degradation of target mRNA by endonuclease complexes guided by approximately 21 nucleotide (nt) short interfering RNAs (siRNAs). A similar process regulates the expression of some developmental genes through approximately 21 nt microRNAs. Plants have four types of Dicer-like (DCL) enzyme, each producing small RNAs with different functions. Here, we show that DCL2, DCL3 and DCL4 in Arabidopsis process both replicating viral RNAs and RNAi-inducing hairpin RNAs (hpRNAs) into 22-, 24- and 21 nt siRNAs, respectively, and that loss of both DCL2 and DCL4 activities is required to negate RNAi and to release the plant's repression of viral replication. We also show that hpRNAs, similar to viral infection, can engender long-distance silencing signals and that hpRNA-induced silencing is suppressed by the expression of a virus-derived suppressor protein. These findings indicate that hpRNA-mediated RNAi in plants operates through the viral defence pathway.
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Kim H, Lim SW, Kim S, Kim JW, Chang YH, Carroll BJ, Kim DK. Monoamine transporter gene polymorphisms and antidepressant response in koreans with late-life depression. JAMA 2006; 296:1609-18. [PMID: 17018806 DOI: 10.1001/jama.296.13.1609] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT Polymorphisms in the serotonin transporter gene (5-HTT) may influence antidepressant response to selective serotonin reuptake inhibitors (SSRIs). The norepinephrine transporter (NET) is the analogous target for norepinephrine reuptake inhibitors (NRIs). OBJECTIVE To determine whether antidepressant responses to SSRIs or NRIs are associated with genetic polymorphisms of the corresponding monoamine transporters. DESIGN, SETTING, AND PATIENTS A 6-week naturalistic treatment study with blinded outcome evaluation of 241 Korean inpatients and outpatients with major depression at an academic psychiatry service. Patients were recruited to the study from March 1998 through February 2003. INTERVENTIONS Treatment with an SSRI (fluoxetine or sertraline; n = 136) or an NRI (nortriptyline; n = 105) antidepressant. Adherence was assessed by measuring plasma concentration at 4 weeks. Patients were genotyped for s/l polymorphisms in 5-HTT promoter region (5-HTTLPR), 5-HTT intron 2 s/l variation, and NET G1287A variation of exon 9. MAIN OUTCOME MEASURES An SSRI and NRI response (defined as > or =50% decrease in Hamilton Rating Scale for Depression score at 6 weeks). RESULTS NRI response was associated with the NET G1287A polymorphism (odds ratio [OR], 7.54; 95% confidence interval [CI], 2.53-22.49; P<.001). An SSRI response was associated with the 5-HTT intron 2 s/l variation (OR, 20.11; 95% CI, 4.27-94.74; P<.001). The 5-HTTLPR was also associated with an SSRI response (OR, 3.34; 95% CI, 1.41-7.91; P = .006). In contrast to studies in white patients, the favorable allele for SSRI response was S 5-HTTLPR. The S 5-HTTLPR was associated also with NRI response (OR, 3.73; 95% CI, 1.32-10.53; P = .01). The NET polymorphism was not associated with an SSRI response. The NET G1287A GG genotype (56% of the population) was associated with better response to the NRI (83.3% [35/42]) than to SSRI (58.7% [44/75]) (OR, 3.52; 95% CI, 1.39-8.95; P = .006). Some genotype combinations were associated with high rates of antidepressant response and others with low rates of response. CONCLUSIONS Monoamine transporter gene polymorphisms were associated with response to antidepressants with homologous monoamine transporter targets. Combinations of polymorphisms were informative for response and nonresponse. Confirmation of these preliminary findings would permit refined pharmacogenetic selection of antidepressant treatment.
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Conway CR, Chibnall JT, Nelson LA, McGuire JM, Abraham PF, Baram VY, Grossberg GT, Carroll BJ. An open-label trial of adjunctive oxcarbazepine for bipolar disorder. J Clin Psychopharmacol 2006; 26:95-7. [PMID: 16415718 DOI: 10.1097/01.jcp.0000195911.13870.f3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Webster KE, O'Bryan MK, Fletcher S, Crewther PE, Aapola U, Craig J, Harrison DK, Aung H, Phutikanit N, Lyle R, Meachem SJ, Antonarakis SE, de Kretser DM, Hedger MP, Peterson P, Carroll BJ, Scott HS. Meiotic and epigenetic defects in Dnmt3L-knockout mouse spermatogenesis. Proc Natl Acad Sci U S A 2005; 102:4068-73. [PMID: 15753313 PMCID: PMC552976 DOI: 10.1073/pnas.0500702102] [Citation(s) in RCA: 206] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The production of mature germ cells capable of generating totipotent zygotes is a highly specialized and sexually dimorphic process. The transition from diploid primordial germ cell to haploid spermatozoa requires genome-wide reprogramming of DNA methylation, stage- and testis-specific gene expression, mitotic and meiotic division, and the histone-protamine transition, all requiring unique epigenetic control. Dnmt3L, a DNA methyltransferase regulator, is expressed during gametogenesis, and its deletion results in sterility. We found that during spermatogenesis, Dnmt3L contributes to the acquisition of DNA methylation at paternally imprinted regions, unique nonpericentric heterochromatic sequences, and interspersed repeats, including autonomous transposable elements. We observed retrotransposition of an LTR-ERV1 element in the DNA from Dnmt3L-/- germ cells, presumably as a result of hypomethylation. Later in development, in Dnmt3L-/- meiotic spermatocytes, we detected abnormalities in the status of biochemical markers of heterochromatin, implying aberrant chromatin packaging. Coincidentally, homologous chromosomes fail to align and form synaptonemal complexes, spermatogenesis arrests, and spermatocytes are lost by apoptosis and sloughing. Because Dnmt3L expression is restricted to gonocytes, the presence of defects in later stages reveals a mechanism whereby early genome reprogramming is linked inextricably to changes in chromatin structure required for completion of spermatogenesis.
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Steffens DC, Pieper CF, Bosworth HB, MacFall JR, Provenzale JM, Payne ME, Carroll BJ, George LK, Krishnan KRR. Biological and social predictors of long-term geriatric depression outcome. Int Psychogeriatr 2005; 17:41-56. [PMID: 15948303 DOI: 10.1017/s1041610205000979] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVE In this study, we examined 204 older depressed individuals for up to 64 months to determine factors related to depression outcome. We hypothesized that both presence of vascular brain lesions seen on baseline magnetic resonance imaging (MRI) scans and lower baseline social support measures would be related to worse depression outcome. METHOD At study entry, all subjects were at least 59 years old, had a diagnosis of major depression, and were free of other major psychiatric illness and primary neurological illness, including dementia and stroke. Depression was diagnosed via structured interview and clinical assessment by a geriatric psychiatrist who completed a Montgomery Asberg Depression Rating Scale (MADRS) to determine severity of depression. Subjects provided self-report data on social support variables and ability to perform basic and instrumental activities of daily living (ADL, IADL). All subjects agreed to have a baseline standardized MRI brain scan. Ratings of severity of hyperintensities were determined for the periventricular white matter, deep white matter, and subcortical gray matter by two readers who decided by consensus. Treatment was provided by geropsychiatrists following clinical guidelines. Using mixed models to analyze the data, we determined the effect of a variety of demographic, social and imaging variables on the trajectory of MADRS score, the outcome variable of interest. RESULTS MADRS scores decreased steadily over time. In a final HLM model, in which time since entry, a baseline time indicator, age, gender, education and Mini-mental State Examination score were controlled, subjective social support, instrumental ADL impairment, subcortical gray matter severity, and the interactions of time with social network and with subcortical gray matter lesions remained significantly associated with MADRS score. CONCLUSIONS Both social and biological factors at baseline are associated with longitudinal depression severity in geriatric depression.
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