Reversal alterations of amplitude of low-frequency fluctuations in early and late onset, first-episode, drug-naive depression.

Background: It is unclear how patients with early onset depression (EOD) and late onset depression (LOD) differ at the neural level. Using amplitude of low-frequency fluctuations (ALFF) approach, we are to test the hypothesis of the different abnormal neural activities between patients with EOD and LOD.

Methods: Fifteen patients with EOD, 15 patients with LOD, 15 young healthy subjects (HS) and 15 old HS were enrolled in the study. ALFF approach was employed to analyze the images.

Results: ANOVA analysis revealed widespread differences in ALFF values among the four groups throughout frontal, parietal, temporal, occipital cortex, cerebellum and limbic regions. Compared to LOD group, EOD group had higher ALFF in bilateral precuneus, superior medial frontal gyrus and superior frontal gyrus, and lower ALFF in left brainstem and left superior temporal gyrus. Compared to young HS, lower ALFF in left superior/inferior temporal gyrus, left lingual gyrus and right middle occipital gyrus and higher ALFF in left medial frontal gyrus and bilateral superior frontal gyrus were seen in the EOD group; in contrast, in the LOD group, lower ALFF in bilateral superior frontal gyrus and higher ALFF in left superior temporal gyrus were observed. Further ROC analysis suggested that the mean ALFF values in the bilateral superior frontal gyrus and left superior temporal gyrus could serve as markers to separate patients with EOD from individuals with LOD.

Conclusions: Patients with EOD and LOD exhibit reversal pattern of abnormal ALFF in bilateral superior frontal gyrus and left superior temporal gyrus.