title: Physical activity motivation mediates the association between depression symptoms and moderate-to-vigorous physical activity.
abstract: OBJECTIVE
  To test if motivational regulations (i.e., amotivation, external, introjected, identified, and intrinsic) mediate the association between depression symptoms and moderate-to-vigorous physical activity (MVPA) in young adults.
  
  
  METHODS
  A total of 319 young adults from Montreal, Quebec participating in the Nicotine Dependence in Teens (NDIT) study provided self-report data on depression symptoms at age 20 (SD=0.7 years) and motivational regulations at age 24 (SD=0.7 years). MVPA was assessed using a self-report questionnaire at age 20 (i.e., at the same time motivation was measured) and using accelerometers one month later. Multiple mediation analysis with bootstrapping was employed to analyze the data.
  
  
  RESULTS
  Controlling for age, sex and self-reported MVPA at age 20 years; introjected regulation was a significant mediator of the association between depression symptoms and MVPA (R(2) adj=0.12; point estimate=-0.0011; BCa CI=-0.15 to -0.01).
  
  
  CONCLUSIONS
  Depression symptoms may undermine controlling forms of motivation, resulting in decreased MVPA. Intervention strategies may be needed to address depression symptoms in young adults to promote sustained MVPA.
authors.affiliation: University of Toronto, 55 Harbord St., Toronto, Ontario M5S 2W6, Canada. Electronic address: tanya.scarapicchia@mail.utoronto.ca.
authors.forename: Tanya M F
authors.initials: TM
authors.lastname: Scarapicchia
authors.affiliation: University of Toronto, 55 Harbord St., Toronto, Ontario M5S 2W6, Canada. Electronic address: catherine.sabiston@utoronto.ca.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Sabiston
authors.affiliation: Centre de recherche CHUM, University of Montreal, 3850 Saint-Urbain Street, Montreal, Quebec H2W 1T7, Canada; Concordia University, 7141 Sherbrooke West, Montreal, Quebec H4B 1R6, Canada. Electronic address: erin.oloughlin@crchum.qc.ca.
authors.forename: Erin
authors.initials: E
authors.lastname: O'Loughlin
authors.affiliation: University of Ottawa, 125 University Private, Ottawa, Ontario K1N 6N5, Canada. Electronic address: jennifer.brunet@uottawa.ca.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Brunet
authors.affiliation: University of Toronto, 55 Harbord St., Toronto, Ontario M5S 2W6, Canada; Centre for Addiction and Mental Health, 33 Russell Street, Toronto, Ontario M5S 2S1, Canada. Electronic address: michael.chaiton@camh.ca.
authors.forename: Michael
authors.initials: M
authors.lastname: Chaiton
authors.affiliation: Centre de recherche CHUM, University of Montreal, 3850 Saint-Urbain Street, Montreal, Quebec H2W 1T7, Canada.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: O'Loughlin
mesh_terms: D003863:Depression / Q000503:physiopathology*; D015444:Exercise / Q000523:psychology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009042:Motivation; D005082:Physical Exertion; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Exercise; Intention; Mental health; Organismic Integration Theory