Cognitive and neurological impairment in mood disorders.

Disorders of mood are accompanied by a range of cognitive and neurological impairments. Similar types of cognitive deficits are shared by patients with unipolar depression and bipolar disorder. Given the disparate clinical nature of these two disorders, it is interesting and informative to understand that they share common impairments in cognition. Neuro-imaging studies indicate that these impairments in both patient populations may be subserved by disruptions of the dorsal lateral and ventral medial PFC. An important problem that remains for clinicians is that some neurological symptoms are linked specifically to the adverse pharmacological effects of antidepressant agents, mood stabilizers, and neuroleptic agents. Research has shown a relation between mood and cognitive ability. Studies also have shown an association between mood and specific types of neurological dysfunction. Although few studies have examined all three symptom domains within one investigation, preliminary reports indicate that mood, cognition, and motor function may be linked to one another by complex mechanisms. Moreover, either type of abnormality that persists in the euthymic state suggests that a fundamental neural dysfunction is unaffected by treatment with existing means. Understanding the neural mechanisms that underlie mood, cognition, and movements may help to devise better treatments that do not influence cognitive or neurological functions,yet treat mood successfully.