Do cortisol levels vary with depression, anxiety and ADHD symptoms pre and post probiotic intervention?
LE3 .A278 2015
Bachelor of Science
The relation between salivary cortisol levels and psychiatric symptoms post-probiotic and placebo intervention was studied in adults with anxiety and negative mood, and children with ADHD and anxiety symptoms. Participants were randomly assigned to conditions, and consumed either a probiotic or placebo powder daily. Next was a washout period, and a second intervention phase, where participants received whichever powder they had not taken already. Cortisol samples and mental health symptom measures were collected at baseline, and at the end of each phase. Saliva samples were collected from 49 adult participants, and 11 children. Results were inconsistent with the hypothesis that cortisol levels would decrease after probiotic intervention in those with anxiety and/or mood symptoms, but increase in those with ADHD symptoms. Results showed a general trend of increasing cortisol levels across conditions in all groups. However, the changes were non-significant. The hypothesis that cortisol levels would positively correlate with mental health symptoms was also not supported; instead, cortisol levels were negatively correlated with anxiety symptoms in adults, and no significant correlations were found in children.
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