title: Assessment of the cortisol awakening response: Expert consensus guidelines.
abstract: The cortisol awakening response (CAR), the marked increase in cortisol secretion over the first 30-45 min after morning awakening, has been related to a wide range of psychosocial, physical and mental health parameters, making it a key variable for psychoneuroendocrinological research. The CAR is typically assessed from self-collection of saliva samples within the domestic setting. While this confers ecological validity, it lacks direct researcher oversight which can be problematic as the validity of CAR measurement critically relies on participants closely following a timed sampling schedule, beginning with the moment of awakening. Researchers assessing the CAR thus need to take important steps to maximize and monitor saliva sampling accuracy as well as consider a range of other relevant methodological factors. To promote best practice of future research in this field, the International Society of Psychoneuroendocrinology initiated an expert panel charged with (i) summarizing relevant evidence and collective experience on methodological factors affecting CAR assessment and (ii) formulating clear consensus guidelines for future research. The present report summarizes the results of this undertaking. Consensus guidelines are presented on central aspects of CAR assessment, including objective control of sampling accuracy/adherence, participant instructions, covariate accounting, sampling protocols, quantification strategies as well as reporting and interpreting of CAR data. Meeting these methodological standards in future research will create more powerful research designs, thus yielding more reliable and reproducible results and helping to further advance understanding in this evolving field of research.
authors.affiliation: Department of Psychology, TU Dresden, Dresden, Germany. Electronic address: tobias.stalder@tu-dresden.de.
authors.forename: Tobias
authors.initials: T
authors.lastname: Stalder
authors.affiliation: Department of Psychology, TU Dresden, Dresden, Germany.
authors.forename: Clemens
authors.initials: C
authors.lastname: Kirschbaum
authors.affiliation: Department of Psychology, University of Regensburg, Regensburg, Germany.
authors.forename: Brigitte M
authors.initials: BM
authors.lastname: Kudielka
authors.affiliation: School of Education and Social Policy, Northwestern University, Evanston, USA.
authors.forename: Emma K
authors.initials: EK
authors.lastname: Adam
authors.affiliation: Department of Psychiatry, McGill University, Montreal, Canada.
authors.forename: Jens C
authors.initials: JC
authors.lastname: Pruessner
authors.affiliation: Department of Psychology, University of Regensburg, Regensburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Wüst
authors.affiliation: School of Applied Psychology, University College Cork, Cork, Ireland.
authors.forename: Samantha
authors.initials: S
authors.lastname: Dockray
authors.affiliation: Department of Psychology, University of Westminster, London, UK.
authors.forename: Nina
authors.initials: N
authors.lastname: Smyth
authors.affiliation: Department of Psychology, University of Westminster, London, UK.
authors.forename: Phil
authors.initials: P
authors.lastname: Evans
authors.affiliation: Department of Psychology, Trier University, and Stresszentrum Trier, Germany.
authors.forename: Dirk H
authors.initials: DH
authors.lastname: Hellhammer
authors.affiliation: Department of Psychology, TU Dresden, Dresden, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Miller
authors.affiliation: Department of Psychology, Northumbria University, Newcastle, UK.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Wetherell
authors.affiliation: Department of Psychiatry, University of Montreal, Montreal, Quebec, Canada.
authors.forename: Sonia J
authors.initials: SJ
authors.lastname: Lupien
authors.affiliation: Department of Psychology, University of Westminster, London, UK.
authors.forename: Angela
authors.initials: A
authors.lastname: Clow
mesh_terms: D002940:Circadian Rhythm; D032921:Consensus; D003940:Diagnostic Techniques, Endocrine / Q000592:standards*; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis* / Q000378:metabolism; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012463:Saliva / Q000737:chemistry* / Q000378:metabolism; D013048:Specimen Handling / Q000379:methods / Q000592:standards*; D014851:Wakefulness / Q000502:physiology*
chemical_list: D006854:Hydrocortisone
keywords: Adherence; CAR; Covariates; Guidelines; Measurement; Saliva