How to assess stress biomarkers for idiographic research?. (December 2015)

• Record Type: Journal Article
• Authors: van Ockenburg, Sonja L.; Booij, Sanne H.; Riese, Harriëtte; Rosmalen, Judith G.M.; Janssens, Karin A.M.
• Is Part Of: Psychoneuroendocrinology. Volume 62(2015:Dec.)
• Page Start: 189
• Page End: 199
• Publication Date: 2015-12
• Subjects: Idiographic -- Cortisol -- Catecholamines -- Repeated measures -- Time series -- Hair -- Nails; Psychoneuroendocrinology -- Periodicals; Endocrinology -- Periodicals; Neurology -- Periodicals; Psychiatry -- Periodicals; Neuropsychoendocrinologie -- Périodiques; 616.8
• DOI: 10.1016/j.psyneuen.2015.08.002
• Languages: English
• ISSNs: 0306-4530

Abstract

Highlights: Idiographic designs enable studying person-specific biomarker associations. Saliva and urine are suitable to examine processes with short-term fluctuations. Hair and nails are more suitable to examine processes with long-term fluctuations. Idiographic studies provide new insights in stress-health associations. Abstract: Associations between stress-related biomarkers, like cortisol or catecholamines, and somatic or psychological symptoms have often been examined at the group level. Studies using this nomothetic approach reported equivocal findings, which may be due to high levels of intra-individual variance of stress biomarkers. More importantly, analyses at the group level provide information about the average patient, but do not necessarily have meaning for individual patients. An alternative approach is to examine data at the level of individual patients in so-called idiographic research. This method allows identifying individuals in whom symptoms are explained by preceding alterations in specific stress biomarkers, based on time series of symptoms and stress biomarkers. To create time series of sufficient length for statistical analysis, many subsequent stress biomarker measurements are needed for each participant. In the current paper, different matrices (i.e. saliva, urine, nail and hair) are discussed in light of their applicability for idiographic research. This innovative approach might lead to promising new insights in the association between stress biomarkers and psychological or somatic symptoms. New collection tools for stress biomarkers, like the use of sweat pads, automated microdialysis systems, dried blood spots, or smartphone applications, might contribute to the feasibility and implementation of idiographic research in the future.