Abnormal Alterations of Regional Spontaneous Neuronal Activity in Inferior Frontal Orbital Gyrus and Corresponding Brain Circuit Alterations: A Resting-State fMRI Study in Somatic Depression

Conclusions: Our findings suggest that abnormal differences in the regional spontaneous neuronal activity of the right inferior frontal orbital gyrus were associated with dysfunction patterns of the corresponding brain circuits during rest in SD patients, including the limbic-cortical systems and the default mode network. This may be an important aspect of the underlying mechanisms for pathogenesis of SD at the neural level.IntroductionA major depressive disorder (MDD) is characterized by the presence of a depressive mood, a loss of interest or pleasure, psychomotor changes, guilt, worthlessness and sleep abnormalities, and it is one of the most common mood disorders (1). An MDD that is accompanied by somatic symptoms, including fatigue, appetite and sleep disturbance, was defined by Silverstein as somatic depression (SD) (2). It has been found that SD differs from non-somatic depression (NSD) in regards to the gender ratio (3–5), developmental patterns (6), and awareness of behavioural errors (7). In addition, in the Star*D study, the response to biological-based treatments, including Citalopram, Sertraline, and others, was better for NSD than for SD (8). Thompson and Bland found that the SD hypothesis can only account for a relatively small amount of the depression variance (9). One interpretation is that SD may be rooted in psychosocial forces while NSD may be rooted more strongly in genetic and endogenous forces (6). In individuals with MDD, the somatic symptoms ap...
Source: Frontiers in Psychiatry - Category: Psychiatry Source Type: research