Peters AT, Smith RA, Kassel MT, Hagan M, Maki P, Van Meter A, Briceño EM, Ryan KA, Weldon AL, Weisenbach SL, Starkman MN, Langenecker SA. A pilot investigation of differential neuroendocrine associations with fronto-limbic activation during semantically-cued list learning in mood disorders.
J Affect Disord 2018;
239:180-191. [PMID:
30014958 DOI:
10.1016/j.jad.2018.07.006]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 06/18/2018] [Accepted: 07/01/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND
Decreased volume and disrupted function in neural structures essential for memory formation (e.g. medial temporal lobe and prefrontal cortex) are common among individuals with depression. Hypothalamic-pituitary-axis function, as reflected by measurement of cortisol levels, is linked to neural activity during memory encoding in healthy people. However, it is not as well understood whether cortisol is associated with alterations in fronto-temporal recruitment during memory encoding in depression.
METHODS
In this pilot study, we evaluated associations between cortisol and neural activation during memory encoding in 62 adults (18-65 years) with mood disorders (MD; n = 39, 66.7% female), including major depression (n = 28) and bipolar I disorder (n = 11), and healthy controls (HC; n = 23, 43.5% female). Participants provided salivary cortisol samples before and after completing a semantically-cued list-learning task during 3-Tesla fMRI. Links between pre-scan cortisol (and cortisol change) and activation during encoding were evaluated using block and event-related models.
RESULTS
Overall, pre-scan cortisol level was positively associated with greater engagement of fronto-limbic activation during the encoding block. However, in MD, pre-scan cortisol was associated with attenuated activation during encoding in medial frontal, superior and middle temporal gyri, insula, lingual gyrus, and claustrum relative to HCs. Cortisol-related attenuation of activation in MD was also observed during encoding of words subsequently recalled in the ventral anterior cingulate, hypothalamus, and middle temporal gyrus. By and large, cortisol change (pre/post scan) predicted the same pattern of findings in both block and event-related contrasts.
LIMITATIONS
Although analyses accounted for variations in scanner time of day, circadian alterations in cortisol may have introduced variability into the results.
CONCLUSIONS
Pre-scan cortisol may selectively interfere with recruitment of important fronto-temporal memory circuitry in mood disorders. The inverted associations between cortisol and neural function in MD relative to HC also elucidate potentially unique pathophysiological markers of mood disorders.
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