title: Establishment of an animal model of depression contagion.
abstract: BACKGROUND
  Depression is a common and important cause of morbidity, and results in a significant economic burden. Recent human studies have demonstrated that that depression is contagious, and depression in family and friends might cumulatively increase the likelihood that a person will exhibit depressive behaviors. The mechanisms underlying contagion depression are poorly understood, and there are currently no animal models for this condition.
  
  
  METHODS
  Rats were divided into 3 groups: depression group, contagion group, and control group. After induction of depression by 5 weeks of chronic unpredictable stress, rats from the contagion group were housed with the depressed rats (1 naïve rat with 2 depressed rats) for 5 weeks. Rats were then subjected to sucrose preference, open field, and forced swim tests.
  
  
  RESULTS
  The sucrose preference was significantly reduced in the depressed rats (p<0.01) and contagion depression rats (p<0.01). Climbing time during forced swim test was reduced in the depression and contagion depression groups (p<0.001), whereas immobility time was significantly prolonged in only the depression group (p<0.001). Rats in both the depression (p<0.05) and depression contagion group (p<0.005) had decreased total travel distance and decreased mean velocity in the open field test, whereas the time spent in the central part was significantly shorter in only the depression group (p<0.001).
  
  
  CONCLUSIONS
  In this study, for the first time we demonstrated depression contagion in an animal model. A reliable animal model may help better understand the underlying mechanisms of contagion depression, and may allow for future investigations of the studying therapeutic modalities.
authors.affiliation: Division of Anesthesiology and Critical Care, Soroka Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel. Electronic address: matthewboykoresearch@gmail.com.
authors.forename: Matthew
authors.initials: M
authors.lastname: Boyko
authors.affiliation: Division of Anesthesiology and Critical Care, Soroka Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel.
authors.forename: Ruslan
authors.initials: R
authors.lastname: Kutz
authors.affiliation: Division of Anesthesiology and Critical Care, Soroka Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel.
authors.forename: Julia
authors.initials: J
authors.lastname: Grinshpun
authors.affiliation: Division of Anesthesiology and Critical Care, Soroka Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel.
authors.forename: Vladislav
authors.initials: V
authors.lastname: Zvenigorodsky
authors.affiliation: Department of Anesthesiology, Yale University School of Medicine, New Haven, CT, USA.
authors.forename: Shaun E
authors.initials: SE
authors.lastname: Gruenbaum
authors.affiliation: Department of Anesthesiology, Yale University School of Medicine, New Haven, CT, USA.
authors.forename: Benjamin F
authors.initials: BF
authors.lastname: Gruenbaum
authors.affiliation: Division of Anesthesiology and Critical Care, Soroka Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel.
authors.forename: Evgeni
authors.initials: E
authors.lastname: Brotfain
authors.affiliation: Division of Anesthesiology and Critical Care, Soroka Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel.
authors.forename: Yoram
authors.initials: Y
authors.lastname: Shapira
authors.affiliation: Division of Anesthesiology and Critical Care, Soroka Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel.
authors.forename: Alexander
authors.initials: A
authors.lastname: Zlotnik
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D003863:Depression / Q000523:psychology*; D004195:Disease Models, Animal; D005518:Food Preferences / Q000523:psychology; D007398:Interpersonal Relations; D008124:Locomotion; D008297:Male; D009043:Motor Activity; D051381:Rats; D017207:Rats, Sprague-Dawley; D012149:Restraint, Physical / Q000523:psychology*; D013315:Stress, Psychological / Q000150:complications / Q000523:psychology*; D013395:Sucrose; D013550:Swimming / Q000523:psychology; D013997:Time Factors
chemical_list: D013395:Sucrose
keywords: Animal model; Contagion; Depression; Rats