Subcortical Structures and Neuropsychiatric Illness

Subcortical structures play an important role in modulating mood, drive, memory, executive functions, and cognitive timing. Subcortical structures are intimately linked with the frontal lobe and limbic system. Key subcortical structures regulating behavior include the caudate nucleus, the ventral striatum, the ventral pallidum, and the dorsomedial and reticular nuclei of the thalamus. Some degenerative diseases affect subcortical nuclear and white matter structures, causing involuntary movements and abnormal behavior. Primary psychiatric illnesses, such as obsessive-compulsive disorder, have been proposed to arise from dysfunction in the frontostriatal-thalamic circuits. The neuroanatomical and neurochemical organization of these subcortical systems mediating complex behaviors and the interactions between behavioral and motor systems are increasingly well understood. Undoubtedly, our newer understanding of subcortical systems will help us to unravel the pathophysiology of some neuropsychiatric disorders.