Shared and Distinct Fractional Amplitude of Low-Frequency Fluctuation Patterns in Major Depressive Disorders With and Without Gastrointestinal Symptoms

Figures

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  Figure 1. Brain regions showing significantly different fALFF values across three groups at a false discovery rate (FDR)-corrected p < 0.05. The color bar indicates the F values based on ANCOVA. fALFF, fractional amplitude of low-frequency fluctuation; ANCOVA, analysis of covariance.

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  Figure 2. Regional fALFF differences between GI-MDD patients and nGI-MDD patients. The color bar indicates the t values from post-hoc t-tests. Red and blue colors denote increased and decreased fALFF, respectively. fALFF, fractional amplitude of low-frequency fluctuation; GI-MDD, major depressive disorder with gastrointestinal symptoms; nGI-MDD, major depressive disorder without gastrointestinal symptoms.

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  Figure 3. Statistical maps showing the fALFF differences between GI-MDD patients and HCs. The color bar indicates t values from post-hoc t-tests. Red and blue colors denote increased and decreased fALFF, respectively. fALFF, fractional amplitude of low-frequency fluctuation; GI-MDD, major depressive disorder with gastrointestinal symptoms; HCs, healthy controls.

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  Figure 4. Statistical maps showing the fALFF differences between nGI-MDD patients and HCs. The color bar indicates t values from post-hoc t-tests. Red and blue colors denote increased and decreased fALFF, respectively. fALFF, fractional amplitude of low-frequency fluctuation; nGI-MDD, major depressive disorder without gastrointestinal symptoms; HCs, healthy controls.

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  Figure 5. Correlations between abnormal fALFF and clinical variables. For all MDD patients, a negative correlation was found between the scores of weight loss in HRSD-17 and the fALFF of the left superior MPFC (A). The severity of GI symptoms was found positively correlated with the fALFF values of the right superior frontal gyrus/middle frontal gyrus (B) and negatively correlated with the fALFF values of the left superior MPFC (C). fALFF, fractional amplitude of low-frequency fluctuation; MDD, major depressive disorder; HRSD-17, 17-item Hamilton Rating Scale for Depression; MPFC, medial prefrontal cortex.

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  Figure 6. Visualization of the classification using the combination of fALFF values of the left superior MPFC and the right superior frontal gyrus/middle frontal gyrus through SVM. (A) SVM parameter results with 3D view. (B) Classified map of the results. Green crosses represent GI-MDD patients and red crosses represent GI-MDD patients. fALFF, fractional amplitude of low-frequency fluctuation; MPFC, medial prefrontal cortex; SVM, support vector machine; GI-MDD, major depressive disorder with gastrointestinal symptoms; nGI-MDD, major depressive disorder without gastrointestinal symptoms.