A Review of the Neurobiological Pathways Involved in the Effect of Depression on Memory

Depression is a pervasive neuropsychiatric disorder that is intricately intertwined with memoryprocesses. In this abstract, we will review the biological mechanisms that underlie depressionrelatedmemory deficits, namely neurotransmitter dynamics and the Dentate Gyrus (DG) of thehippocampus (HPC). The imbalance of neurotransmitters, which is the hallmark of depression,mainly involves complex molecules such as acetylcholine, norepinephrine, dopamine, gammaaminobutyric acid (GABA), glutamate, and serotonin. Disruption of these neurotransmitters hasprofound consequences on memory-related synaptic plasticity in the DG HPC region and leadsto cognitive disorders in depression. Dopamine, mainly known for its role in reward pathwaysand mood regulation, also appears as a determinant in depression-induced memory impairments.On the other hand, serotonin is an inhibitory neurotransmitter that is related to the regulation ofmood, appetite and emotional states, and its dysfunction directly affects memory. Glutamate andGABA are inhibitory and excitatory neurotransmitters, respectively, which play a key role inshaping depression's impact on memory. An imbalance in the GABAergic signaling pathway canlead to impaired inhibitory control and affect memory consolidation and recovery processes. Atthe same time, changes in the glutamatergic pathway, especially in the DG region, are associatedwith learning and memory impairments in depressive conditions. In fact, the neuroanatomicalfocus extends to the DG HPC region, which is a critical region in memory. Depression-inducedchanges affecting neurogenesis, synaptic plasticity, and neuronal morphology in the DG regionlead to disruption of memory consolidation and retrieval processes. Finally, in order to betterunderstand the relationship between depression and memory, research should be done to revealthe neural cascades between these two phenomena. For example, designing research to elucidatethe neurochemical intricacies of the DC HPC region can be an effective step in understanding ofneurobiology. Therefore, in this abstract, while providing insights about the neurobiologicalpathways between depression and memory, we emphasize the necessity of conducting moreresearch and studies in this field.