AUTHOR=Robillard Rébecca , Lagopoulos Jim , Hermens Daniel F. , Naismith Sharon L. , Rogers Naomi L. , White Django , Carpenter Joanne S. , Kaur Manreena , Scott Elizabeth M. , Hickie Ian B. 

TITLE=Lower In vivo Myo-Inositol in the Anterior Cingulate Cortex Correlates with Delayed Melatonin Rhythms in Young Persons with Depression

JOURNAL=Frontiers in Neuroscience

VOLUME=11

YEAR=2017

URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2017.00336

DOI=10.3389/fnins.2017.00336

ISSN=1662-453X

ABSTRACT=<p>Myo-inositol, a second messenger glucose isomer and glial marker, is potentiated by melatonin. In addition to common abnormalities in melatonin regulation, depressive disorders have been associated with reduced myo-inositol in frontal structures. This study examined associations between myo-inositol in the anterior cingulate cortex and the timing of evening melatonin release. Forty young persons with unipolar depression were recruited from specialized mental health services (20.3 ± 3.8 years old). Healthy controls were recruited from the community (21.7 ± 2.6 years old). The timing of dim light melatonin onset (DLMO) was estimated using salivary melatonin sampling. Myo-inositol concentrations (MI/CrPCr ratio) in the anterior cingulate cortex were obtained using proton magnetic resonance spectroscopy. After controlling for age, sex, and CrPCr concentration the depression group had significantly lower MI/CrPCr ratios than healthy controls [<italic>F</italic><sub>(4, 75)</sub> = 11.4, <italic>p</italic> = 0.001]. In the depression group, later DLMO correlated with lower MI/CrPCr ratio (<italic>r</italic> = −0.48, <italic>p</italic> = 0.014). These findings suggest that neurochemical changes in the frontal cortex are associated with circadian disruptions in young persons with depression.</p>