Apathy is a neurobehavioral disorder characterized by a lack of interest in environmental stimuli, manifest as listlessness, paucity of spontaneous movement (akinesia) or speech (mutism), and lack of initiative, spontaneity and drive. These are all features of the abulic state, and it has been suggested that apathy and abulia represent different points on a continuum of motivational and emotional deficit, abulia being at the more severe end. The diminished motivation of apathy should not be attributable to impaired level of consciousness, emotional distress, or cognitive impairment although it may coexist with the latter, as in Alzheimer’s disease. Apathy is a specific neuropsychiatric syndrome, distinct from depression.
Apathy may be observed in diseases affecting frontal-subcortical structures, for example in the frontal lobe syndrome affecting the frontal convexity, or following multiple vascular insults to paramedian diencephalic structures (thalamus, subthalamus, posterior lateral hypothalamus, mesencephalon) or the posterior limb of the internal capsule; there may be associated cognitive impairment of the so-called "subcortical" type in these situations (e.g., in Huntington’s disease). Apathy is also described following amphetamine or cocaine withdrawal, in neuroleptic-induced akinesia and in psychotic depression.
SSRIs may sometimes be helpful in the treatment of apathy.
Levy M, Cummings JL, Fairbanks LA et al. Apathy is not depression. Journal of Neuropsychiatry and Clinical Neuroscience 1998; 10: 314-319 Marin RS. Differential diagnosis and classification of apathy. American Journal of Psychiatry 1990; 147: 22-30
Mega MS, Cummings JL, Fiorello T, Gornbein J. The spectrum of behavioral changes in Alzheimer’s disease. Neurology 1996; 46: 130-135 Starkstein SE, Fedorof JP, Price TR, Leiguarda R, Robinson RG. Apathy following cerebrovascular lesions. Stroke 1993; 24: 1625-1630