title: The Interplay of Genetics, Behavior, and Pain with Depressive Symptoms in the Elderly.
abstract: OBJECTIVE
  About 25% of older adults suffer from depressive symptoms. Commonly studied candidate genes associated with depression include those that influence serotonin (SLC6A4), dopamine (COMT), or neuroplasticity (BDNF, NTRK3). However, the majority of candidate gene studies do not consider the interplay of genetics, demographic, clinical, and behavioral factors and how they jointly contribute to depressive symptoms among older adults. The purpose of this study was to gain a more comprehensive understanding of depressive symptoms among older adults.
  
  
  METHODS
  In this descriptive study, demographic, behavioral, and clinical characteristics (age, gender, comorbidities, volunteering, physical activity, pain, and fear of falling) were obtained via interview of 114 residents in a continuing care retirement community. Peripheral whole blood was collected for DNA extraction. We examined common single nucleotide polymorphisms (SNPs) in the aforementioned genes using path analyses.
  
  
  RESULTS
  SNPs in the NTRK3 gene, pain, physical activity, and fear of falling were directly associated with depressive symptoms in older adults. Those who had polymorphisms in the NTRK3 gene, pain, fear of falling, and were less physically active were more likely to exhibit depressive symptoms. None of the SNPs in SLC6A4, COMT, or BDNF genes were significantly associated with depressive symptoms.
  
  
  CONCLUSIONS
  Our use of a path analysis to examine a biopsychosocial model of depressive symptoms provided the opportunity to describe a comprehensive clinical picture of older adults at risk for depressive symptoms. Thus, interventions could be implemented to identify older adults at risk for depressive symptoms.
authors.affiliation: University of Maryland School of Nursing, Baltimore. klinedinst@son.umaryland.edu.
authors.forename: N Jennifer
authors.initials: NJ
authors.lastname: Klinedinst
authors.affiliation: University of Maryland School of Nursing, Baltimore.
authors.forename: Barbara
authors.initials: B
authors.lastname: Resnick
authors.affiliation: Division of Endocrinology Department of Medicine, University of Maryland Baltimore.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Yerges-Armstrong
authors.affiliation: University of Maryland School of Nursing, Baltimore.
authors.forename: Susan G
authors.initials: SG
authors.lastname: Dorsey
mesh_terms: D000058:Accidental Falls; D000368:Aged; D000369:Aged, 80 and over; D040561:Assisted Living Facilities; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D003430:Cross-Sectional Studies; D003863:Depression / Q000097:blood / Q000175:diagnosis / Q000235:genetics*; D005239:Fear; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006801:Humans; D007407:Interviews as Topic; D015810:Linkage Disequilibrium; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000523:psychology*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D020812:Receptor, trkC / Q000235:genetics*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D011795:Surveys and Questionnaires
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; C588010:COMT protein, human; D002394:Catechol O-Methyltransferase; D020812:Receptor, trkC
keywords: Assisted living facilities; Depression; Genetics; Psychosocial