Cortisol levels in fingernails and neurocognitive performance in euthymic bipolar I patients and healthy controls

Abstract

Neurocognitive impairment has been found in bipolar patients. However, the cause of this is not fully understood. Hypercortisolaemia is a possible cause, but there is no agreement about this. This may be because previous sampling methods assess acute cortisol levels, while the association between psychopathology and cortisol might be explained by chronic levels. Fingernails can now be used to measure chronic cortisol concentration (CCC). In this study we assessed CCC in euthymic bipolar I patients (BD-1) and matched controls using fingernails to see whether differences in CCC influenced neurocognitive abilities.