Daycare attendance, stress, and mental health.
OBJECTIVE
Daycare stress can be indexed by cortisol, and elevated levels of cortisol have been implicated in the onset and development of mental health disorders. Our objective was to quantify the associations between daycare and cortisol and to identify individual and environmental conditions under which daycare attendance is associated with cortisol concentrations.


METHODS
We used Cohen effect size statistics to quantify these associations and to compare them across 11 published studies that were identified with MEDLINE and PsycINFO.


RESULTS
Cortisol levels increased during the daycare day, whereas they decreased when children stayed at home. The mean effect size was d = 0.72. The magnitude of the daycare-stress relation seemed to vary under 3 specific conditions. First, the effect size was larger for children in low-quality daycare (d = 1.15), whereas there was essentially little or no effect for children in high-quality daycare (d = 0.10). Second, the effect size was larger for preschoolers (aged 39 to 59 months) (d = 1.17) than for infants (aged 3 to 16 months) (d = 0.11) or school-aged children (aged 84 to 106 months) (d = 0.09). Third, children with difficult temperaments in daycare were more likely to exhibit a rising pattern of cortisol, compared with children who were not difficult.


CONCLUSIONS
Our review suggests that daycare attendance in relatively low-quality daycare conditions and for children with difficult temperaments may result in atypical cortisol elevation. Although the link between atypical cortisol elevation and mental health requires further study, programs aimed at improving the quality of daycare services during the preschool years are expected to lead to better physiological adaptation to daycare and to reduce the risks of mental health problems.
Geoffroy
Marie-Claude
MC
Department of Psychology, Université de Montréal, Quebec. mc.geoffroy@umontreal.ca
Côté
Sylvana M
SM
Parent
Sophie
S
Séguin
Jean Richard
JR
D002648:Child; D002656:Child Day Care Centers / Q000706:statistics & numerical data*; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis*; D007223:Infant; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology / Q000517:prevention & control*; D012463:Saliva / Q000737:chemistry*; D013315:Stress, Psychological / Q000453:epidemiology* / Q000378:metabolism*
D006854:Hydrocortisone