title: Associations between depressive symptoms and memory deficits vary as a function of insulin-like growth factor (IGF-1) levels in healthy older adults.
abstract: OBJECTIVE
  Accumulating evidence suggests an adverse association between depressive symptoms and cognition, but a positive association between insulin-like growth factor (IGF)-1 and cognition. The present study examined the influence of IGF-1 in the relationship between depressive symptoms and learning and memory.
  
  
  METHODS
  A cross-sectional study of 94 healthy fit older adults. Blood was collected and plasma IGF-1 was measured. Depressive symptoms were assessed with the Geriatric Depression Scale (GDS), and learning and memory were assessed using the Rey Auditory Verbal Learning Test (AVLT).
  
  
  RESULTS
  Among older adults with lower IGF-1 levels, higher depressive symptoms scores were associated with lower AVLT delayed recall and recognition. Older adults with higher IF-1 levels showed no associations between depressive symptoms and memory.
  
  
  CONCLUSIONS
  The association between depressive symptoms and cognition is stronger among older adults with lower levels of circulating IGF-1. Further validation studies on groups with depression or different stages of cognitive impairment are needed. IGF-1 may be a novel intervention target for slowing cognitive decline in older adults with depressive symptoms.
authors.affiliation: School of Nursing, University of Rochester Medical Center, Rochester, NY 14642, USA; Department of Psychiatry, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA. Electronic address: vankee_lin@urmc.rochester.edu.
authors.forename: Feng
authors.initials: F
authors.lastname: Lin
authors.affiliation: Department of Psychology, Ohio University, Athens, OH 45701, USA.
authors.forename: Julie
authors.initials: J
authors.lastname: Suhr
authors.affiliation: Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Diebold
authors.affiliation: Department of Psychiatry, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA.
authors.forename: Kathi L
authors.initials: KL
authors.lastname: Heffner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition; D003430:Cross-Sectional Studies; D003863:Depression / Q000097:blood* / Q000150:complications / Q000523:psychology; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008569:Memory Disorders / Q000097:blood* / Q000150:complications / Q000523:psychology; D008875:Middle Aged
chemical_list: D007334:Insulin-Like Growth Factor I
keywords: Depressive symptoms; IGF-1; Learning; Memory