Arch Gen Psychiat
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White matter hyperintensities (WMHs) are bright foci seen in the parenchyma of the brain on T2-weighted cranial magnetic resonance imaging (MRI) scans and are associated with geriatric depression. Because they are associated with age, they should increase in number and size over time. To our knowledge, this is the first longitudinal, volumetric MRI study of WMHs in depression. ⋯ Greater progression of WMH volume is associated with poor outcomes in geriatric depression. Future work is needed to develop means of slowing the rate of WMH progression and to determine whether this will lead to improved depression outcomes in elderly persons.
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Human affective responses appear to be regulated by limbic and paralimbic circuits. However, much less is known about the neurochemical systems engaged in this regulation. The mu-opioid neurotransmitter system is distributed in, and thought to regulate the function of, brain regions centrally implicated in affective processing. ⋯ These data demonstrate dynamic changes in mu-opioid neurotransmission in response to an experimentally induced negative affective state. The direction and localization of these responses confirms the role of the mu-opioid receptor system in the physiological regulation of affective experiences in humans.