A Short Glance at the Role of Olfaction in Depression

Abstract

Depression as one kind of neuropsychiatric disorder affects tons of population in the world and exerts great economic and social burden. Great efforts have been made during the past decades aiming to decipher the underlying mechanism of this mental disease. Different kinds of mechanisms underlie depression, among which malfunctions in the olfactory system is one important reason. The occurrence of depression has a close association with dysfunctions in the olfactory system, which is highlighted by some brain regions responsible for depression overlapping with areas playing crucial roles in olfaction. The close relationship between olfactory malfunctions and depression is also underscored by the evidence that some patients with depression exhibited a higher probability of odor identifi cation impairment and a reduced olfactory sensitivity as well as smaller olfactory bulb volumes. For reasons of concise and clarity, in the current review we only briefl y summarized some key recent studies pertaining to the relationship between the dysfunctional olfaction and depression, to underscore potentially crucial roles of the normal olfactory system function in ameliorating the probability of the occurrence of depression.

Abnormal GABAergic Neurotransmission in Depression

“…Depression as a neuropsychiatric disorder is characterized by anhedonia and lack of motivation [1], which has led to great social and economic burdens. A plethora of recent studies have highlighted the underlying mechanisms of this mood disorder from different aspects [2][3][4][5][6][7][8][9][10]. Generally, the pathogenesis of depression is closely associated with dysfunctions in neural circuits which, to some extent, are largely resulted from the abnormal neurotransmitter release from presynaptic neurons to their corresponding postsynaptic targets.…”