In bipolar disorder, is hair cortisol a reliable biomarker for mood?

In bipolar disorder, is hair cortisol a reliable biomarker for mood?

Edited by, SNEHA MAVIS

Bipolar disorder (BD) is defined as episodes of depressed, manic, or mixed moods that have a significant impact on the patient's quality of life (QoL). BD is professionally diagnosed and followed up on by psychiatric examination, with no biomarkers yet in clinical use for either diagnosis or follow-up. Cortisol, the stress hormone, is a potential biomarker, although its importance has yet to be determined by correlating cortisol and mood in a group of BD patients.

The current study looked into whether hair levels of cortisol may be used to predict mood in BD patients. 

Participants with BD were admitted to Merchavim's mental health hospital. The qualifying participants had to have a BD diagnosis (DSM III-V), be between the ages of 18 and 65, have stable or no recent medical treatment, and have at least 12 cm of natural hair that has not undergone any cosmetic procedures like perming or dying. The researchers only used data from the first 2 cm of the segment. Because cortisol does not diffuse in human hair, each 2 cm segment corresponds to two months.

Each participant was questioned about their medical history, current medication schedule, and mood evaluation. During the interview, a clinical interview, the Hamilton Depression Rating Scale (HDRS), and the Beck Depression Inventory self-report were all used (BDI). To measure anxiety, the Young Mania Rating Scale (YMRS) was employed. The Hamilton Anxiety Rating Scale (HAM-A) was used to measure anxiety, while the Clinical Global Impressions inventory (CGI) and the Global Assessment of Functioning scale (GAF) were employed to measure overall functioning.

The YMRS scores of all individuals were low, indicating that none of the subjects experienced manic symptoms throughout the research. Log cortisol and YMRS scores also did not correlate. Furthermore, the anxiety and depression scales exhibited a wider range of scores between individuals, indicating a range of anxiety and depressive disorders among the participants. Log hair cortisol and the HDRS and BDI scales showed a substantial positive connection. Additionally, there was a positive association between log cortisol and the HAM-A anxiety scale.

According to the study's findings, cortisol levels found in the first 2 cm of hair taken from BD patients were positively connected with depression scores. Similar to the value of Hemoglobin A1C blood tests for diabetes, cortisol may be useful as a biomarker in psychiatry. The results of this study, according to the researchers, encourage further investigation into the possibility of employing hair cortisol as a mood biomarker to help with follow-up and long-term evaluation of therapy efficacy in BD.