Resting State Magnetic Resonance Imaging Case Control Study Of First-episode Medication-na?ve Adolescent Depression

Background:Depression is a kind of unknown pathogenesis of serious damage to human health and the prevalence of mental illness, there is a rising trend. The prevalence of adolescent depression is higher, adolescent depression results in severe suffering for the affected individuals and a substantial health burden for family members and the society. Function imaging technology is developing rapidly in recent years, we can make the brain structure of high resolution imaging and brain metabolism activities combined, imaging study of the central nervous system of morphology and function. There are far fewer functional brain imaging studies on adolescent depression than on adult depression, but most do not agree, most studies is the study of task state, rarely make the news to the resting state of brain function. Objective:In the resting state, using functional magnetic resonance imaging(f MRI), Compare resting-state brain functioning between first-episode, drug-na?ve adolescents with major depressive disorder and matched controls, The purpose was to study the relationship between clinical manifestations of patients with first-episode depression and brain functional structure changes in the region and to explore the possible pathogenesis of depression. Methods:In 21 cases(male 12 cases, female 9 cases) in first-episode adolescent patients with major depressive disorder and 18 cases(male 10 cases, female 8 cases) healthy controls were recruited. Resting-state functional magnetic resonance imaging has been applied to all the participants. Observed in related brain area fraction low-frequency amplitude(fractional amplitude of low frequency fluctuation,f ALFF) value and local consistency(regional homogeneity,Re Ho)value changes and to analyze the brain function of frist-episode depression in resting state.Results:1. Re Ho analysis: a resting state of depression group compared to normal control group Re Ho value increased regions distributed in the lower right temporal gyrus, the left upper cingulate cortex, left frontal polar, after upper left cingulate cortex, after the bottom left cingulate cortex, left praecuneus, the difference was statistically significant(P<0.05);Decreased regions are widely distributed in the lower right middle temporal gyrus, the difference was statistically significant(P<0.05).2. f ALFF analysis: a resting state of depression group compared to normal control group f ALFF value increased regions distributed in the left upper cingulate cortex, left anterior cingulate cortex, frontal oculomotor areas, the right side of somatosensory cortex, the left side of the hippocampus, difference was statistically significant(P<0.05);decreased in the right frontal orbitofrontal area, after the bottom right cingulate cortex, right orbitofrontal area, cerebellum, difference was statistically significant(P<0.05).Conclusions:1. In the resting state, abnormal brain activity of patients with first-episode depression might exist, limbic system, is one of the most significant part of the regions, it may be one of the underlying mechanisms of first-episode depression.2. Frontal lobe, cingulate gyrus function abnormalities may cause adolescent depression patients with negative emotions; temporal lobe function abnormalities may cause a decrease in the antobiographical memory in patients with depression in adolescent.