Gloria Garcia-Banda1, Karin Chellew2, Joana Fornes3, Gerardo Perez4, Mateu Servera5, Phil Evans6. 1. Research Institute on Health Sciences (IUNICS), University of Balearic Islands, Ctra. de Valldemossa, km 7.5, 07122 Palma de Majorca, Spain. Electronic address: ggbanda@uib.es. 2. Department of Psychology, University of Balearic Islands, Ctra. de Valldemossa, km 7.5, 07122 Palma de Majorca, Spain. 3. Department of Nursing and Physiotherapy, University of Balearic Islands, Ctra. de Valldemossa, km 7.5, 07122 Palma de Majorca, Spain. 4. Clinical Analysis Laboratory, Son Espases University Hospital, Ctra. de Valldemossa, 79, 07120 Palma de Majorca, Spain. 5. Research Institute of Health Sciences (IUNICS), University of Balearic Islands, Ctra. de Valldemossa, km 7.5, 07122 Palma de Majorca, Spain. 6. Psychophysiology and Stress Research Group, University of Westminster, 309 Regent Street, London W1B 2UW, UK.
Abstract
BACKGROUND: There are strong theoretical arguments that those high on Neuroticism (N) should normally exhibit higher prevailing levels of the stress-linked hormone cortisol (C), but findings are inconsistent, probably reflecting methodological weaknesses especially in taking account of C's diurnal cycle. METHODS: High and low N students [Total N=118; mean age=20.99years] were recruited and their salivary cortisol measured, ensuring that saliva samples were numerically adequate to assess C's diurnal cycle over two days with objective verification of sample timing. RESULTS: Cortisol secretion was approximately 20% higher in High N than low N participants in the period of 12h after awakening (p<.008), but no differences in secretion were evident during the first 0.75 of this period, when typically the Cortisol Awakening Response (CAR) rapidly takes cortisol to its daily peak. N effects were thus confined to the 0.75h-12h period (p<.007). Males had approximately 25% higher cortisol secretion levels than females, also confined to the 0.75h-12h period (p<.003). No significant differences between N groups were evident for dynamic measures of cortisol change, viz. the magnitude of CAR rise and subsequent diurnal fall. All effects were controlled for cohort date of study entry, age, smoking status, study day and time of awakening. DISCUSSION: With careful control, it appears that an important theoretically predicted effect exists, and is replicated in different student intake cohorts recruited in different years. Most importantly, findings support several lines of evidence that the period of massive rise in the brief 0-0.75h CAR period should be seen as quite separate from the rest of the diurnal cycle, underpinned by different control mechanisms, and with potentially different correlates.
BACKGROUND: There are strong theoretical arguments that those high on Neuroticism (N) should normally exhibit higher prevailing levels of the stress-linked hormone cortisol (C), but findings are inconsistent, probably reflecting methodological weaknesses especially in taking account of C's diurnal cycle. METHODS: High and low N students [Total N=118; mean age=20.99years] were recruited and their salivary cortisol measured, ensuring that saliva samples were numerically adequate to assess C's diurnal cycle over two days with objective verification of sample timing. RESULTS:Cortisol secretion was approximately 20% higher in High N than low N participants in the period of 12h after awakening (p<.008), but no differences in secretion were evident during the first 0.75 of this period, when typically the Cortisol Awakening Response (CAR) rapidly takes cortisol to its daily peak. N effects were thus confined to the 0.75h-12h period (p<.007). Males had approximately 25% higher cortisol secretion levels than females, also confined to the 0.75h-12h period (p<.003). No significant differences between N groups were evident for dynamic measures of cortisol change, viz. the magnitude of CAR rise and subsequent diurnal fall. All effects were controlled for cohort date of study entry, age, smoking status, study day and time of awakening. DISCUSSION: With careful control, it appears that an important theoretically predicted effect exists, and is replicated in different student intake cohorts recruited in different years. Most importantly, findings support several lines of evidence that the period of massive rise in the brief 0-0.75h CAR period should be seen as quite separate from the rest of the diurnal cycle, underpinned by different control mechanisms, and with potentially different correlates.
Authors: Ian A Boggero; Camelia E Hostinar; Eric A Haak; Michael L M Murphy; Suzanne C Segerstrom Journal: Biol Psychol Date: 2017-09-14 Impact factor: 3.251
Authors: Karissa G Miller; Aidan G C Wright; Laurel M Peterson; Thomas W Kamarck; Barbara A Anderson; Clemens Kirschbaum; Anna L Marsland; Matthew F Muldoon; Stephen B Manuck Journal: Psychoneuroendocrinology Date: 2016-03-05 Impact factor: 4.905
Authors: Tomiko Yoneda; Eileen Graham; Tristen Lozinski; David A Bennett; Daniel Mroczek; Andrea M Piccinin; Scott M Hofer; Graciela Muniz-Terrera Journal: J Pers Soc Psychol Date: 2022-04-11
Authors: Gilda E Ennis; Yang An; Susan M Resnick; Luigi Ferrucci; Richard J O'Brien; Scott D Moffat Journal: Neurology Date: 2016-12-16 Impact factor: 9.910
Authors: Sami Ouanes; Enrique Castelao; Armin von Gunten; Pedro M Vidal; Martin Preisig; Julius Popp Journal: Front Aging Neurosci Date: 2017-03-14 Impact factor: 5.750
Authors: Cristian Sebastian Melia; Virginia Soria; Neus Salvat-Pujol; Ángel Cabezas; Roser Nadal; Mikel Urretavizcaya; Alfonso Gutiérrez-Zotes; José Antonio Monreal; José Manuel Crespo; Pino Alonso; Elisabet Vilella; Diego Palao; José Manuel Menchón; Javier Labad Journal: Biol Sex Differ Date: 2019-12-02 Impact factor: 5.027