MK4MDD

Study Report

Reference
CitationOathes DJ, 2015 PubMed
Full InfoOathes DJ, Hilt LM, Nitschke JB (2015) Affective Neural Responses Modulated by Serotonin Transporter Genotype in Clinical Anxiety and Depression. PLoS ONE 10(2): e0115820. doi:10.1371/journal.pone.0115820

Study
Hypothesis or Background Serotonin transporter gene variants are known to interact with stressful life experiences to increase chances of developing affective symptoms, and these same variants have been shown to influence amygdala reactivity to affective stimuli in non-psychiatric populations. The impact of these gene variants on affective neurocircuitry in anxiety and mood disorders has been studied less extensively.
Sample Information50 generalized anxiety disorder patients, 26 of whom alsomet DSM-IV criteria for social anxiety disorder and/or major depressive disorder, and 39 healthy comparison subjects
Method DetailUtilizing a triallelic assay (5-HTTLPR and rs25531) to assess genetic variation linked with altered serotonin signaling, this fMRI study investigated genetic influences on amygdala and anterior insula activity in 50 generalized anxiety disorder patients, 26 of whom also met DSM-IV criteria for social anxiety disorder and/or major depressive disorder, and 39 healthy comparison subjects. A Group x Genotype interaction was observed for both the amygdala and anterior insula in a paradigm designed to elicit responses in these brain areas during the anticipation of and response to aversive pictures.
Method KeywordsMagnetic resonance images(MRI)
ResultPatients who are S/L(G) carriers showed less activity than their L(A)/L(A) counterparts in both regions and less activity than S/L(G) healthy comparison subjects in the amygdala. Moreover, patients with greater insula responses reported higher levels of intolerance of uncertainty, an association that was particularly pronounced for patients with two LA alleles. A genotype effect was not established in healthy controls.
ConclusionsThese findings link the serotonin transporter gene to affective circuitry findings in anxiety and depression psychopathology and further suggest that its impact on patients may be different from effects typically observed in healthy populations.

Relationships reported by Oathes DJ, 2015