Browsing by Subject "tunnepitoinen ärsyke"

Objective. Early onset major depressive disorder is a serious and recurring illness. There is abnormal brain function associated with depression when processing emotional stimuli. However, we do not know how these abnormalities occur in very young children. The aim of this review is to study brain function abnormalities when processing emotional stimuli in depressed pre-schoolers and the stability of these abnormalities in school aged children. Methods. This thesis reviews studies on pre-school major depressive disorder (PO-MDD) and its effects on brain abnormalities when processing emotional stimuli. Also, studies on school aged children with PO-MDD are included to inspect the stability of the abnormalities apparent in PO-MDD. Studies were included in this review, if they assessed children’s depression at least once during the pre-school period, and children were shown emotional stimuli during a functional magnetic resonance imaging. Results and conclusions. Children with PO-MDD had elevated activation in the limbic system and in the cortical areas associated with the processing of emotional stimuli when compared to their healthy peers. This elevated activation did not differ between positive and negative stimuli. Also, school aged children with PO-MDD had enhanced limbic and cortical activation in the areas associated with the processing of emotional stimuli when compared to their healthy peers. This enhanced activation was associated with the negativity of the stimuli. The connection between the PO-MDD and brain abnormalities in school age may be caused by genetic and environmental factors or the PO-MDD induced changes in brain functions. Because the abnormalities in brain function are already visible in pre-school, early intervention plays an important role. By studying the brain abnormalities associated with PO-MDD, we can develop efficient interventions to support the normal development of childrens’ brains and reduce the frequency and severity of future depressive episodes.