words, apathy is considered a syndrom when lack of motivation is not attributable to such other syndromes as dementia, delirium, or depression. Deciding whether apathy is secondary to some others syndroms depends on the process of evaluating a patient's overall clinical state and judging which symptoms are most prominent. For example, if a patient with diminished interests is intensely dysphoric, a diagnosis of depression would be more likly. The criteria for diagnosing the syndrome of apathy 3 are summarized in table-1.
Patients may show the syndrom of apathy and another syndrome simultaneously, eg, in Parkinson's disease and Alzheimer disease. Patients with Parkinson's disease often present with both apathy and dementia, while patients with Alzheimer disease may exhibit apathy, dementia, and psychosis. In each case, the patients exhibit diminished motivation, but the symptoms meet criteria for some other syndrome, eg, dementia.
Assessment of Apathy
Recognition of apathy has important implications for clinical care because motivation is essential for adaptive behavjor. Comprehensive medical assessment may be needed to evaluate many psychiatric, neurologic, and medical condition that can produce apathy. Taking a through psychosocial history is necessary to determine whether apathy has been present throughout child hood or adult life, whether it is a symptom of a personality disorder or whether it represents a change in personality.The level of motivation must be interpreted in the context of the individual's cultural background and personal experiences.
Apathy is considered to be clinically significant when:
(1) there is evidence of diminished motivation relative to the norms of one age and culture; and (2) the lack of motivation is severe enough to interfere with psychosocial functioning3. In evaluating motivation, it is to remember that apathy need not be prevasive or incapacitating. In fact, adaptive functioning requires selectivity of choices. Healthy individuals are, of necessity, relatively or selectively apathetic about some goal in comparison with others.
Characterizing the individual's skill accomplishments, goals and aspirations, emotional relationship, and social interactions will help distinguish apathy that is adaptive (having functional significance) and selective (making a carefully chosen response) from that which is defensive (meanirig response that is protective but not necessarily functional) and pervasive (meaning always present.)
Apathy Evaluation Scale (AES)5 is the most widely used and extensively validated rating scale for measuring the presence and severity of apathy. This 18-item instrument is specifically designed to assess the elements of apathy's operational definition, namely a decrease in the behavioral, cognitive and emotional concomitants of goal-directed behavior. Self-informant, and clinician-rated versions of the AES have been developed. The validity of the AES has been confirmed in studies of patients with stroke6 and Parkinson's disease. Psychometric analyses have also demonestrated that the AES discriminates between apathy and depression symptoms. Some patients have shown significant apathy without elevation of depression scores, a pattern consistant with the proposed concept of the syndrome of apathy8. Taken together, these and other research findings3 strongly confirm the discriminability of apathy and depression in neuropsychiatric populations.
A recent studyB determined that four items of the Hamilton Depression Rating Scale (HORS-17 items) may be used to estimate apathy. Apathy is assessed by deriving a subtotal score using the following HDRS items: (1) lack of interest; (2) psychomotor retardation; (3) lilCk of energy; and (4) lack of insight. The correlation between the AES and HDRS total scores in this study is significantly reduced when the four "apathy items" are excluded from the HDRS total score. This finding supports the notion that this HDRS subtotal score can serve as a measure of apathy when more specific instruments of apathy are not used.
Differential diagnosis of Apathy
Depression
The essential difference between apathy and depression is that apathy is a syndrome of diminished motivation, whereas depression is defined by disturbances in moodl. Difficultly differentiating the syndromes of apathy and depression is understandable, as both are associated with diminished motivation, often in depression and always in apathy. The most useful features for differentiating apathy and depression occur in the emotional and cognitive areas. Depression is, by definition, a dysphoric state, whereas patients with a syndrome of apathy do not report dysphoria. The emotional response of depressed patients also differs from that of patients with apathy. Whereas apathetic patients show attenuated emotional responses to both positive and negative rewards, depressed patients are biased to perceive and respond selectively to negative events. In the cognitive dimension, individuals with depression often report negative thoughts about the self, the present, and the future9. In apathy, a lack of concern is present, with diminution in goals interests, and curiosity .Furthermore, in depressed patients who claim to lack interest, careful assessment generally reveals that their lack of interest actually reflects despair, hopelessness, and pessimism. Thus, the lack of interest of the depressed individual is due to diminished expectancy of achieving goals that, if anything, are now overvalued. In contrast, patients with apathy value their goals less than they used to and are therefore truly unconcerned.
Delirium
Apathy is a common symptom of delirium. Persons with delirium who are sedate, drowsy, or hypoactive are likely to be characterized as apathetic. Presumably, the mechanism of apathy in these cases is suppression of the reticular activating system by the metabolic effects of medical conditions, or the effects of gross brain disease on the neural connections or blood supply of this system or structures mediating attention.
Dementia
Dementing diseases, particularly those involving the frontal lobes and basal ganglia, often cause apathy. Alzheimer disease may produce apathy, but does not necessarily do so in the earliest stages of the disease. It may cause apathy by impairing the cognitive basis of motivation (via deterioration of frontal lobes and association areas): by disrupting the right parietotemporal circuits involved in perceiving emotional significance of information; or by impairing the subcortical mechaisms necessary for normal mood and drive.
Abulia
Individuals with abulia associated with mesial frontal (ie. anterior cingulate) damage show diminished will or motivation. Abulia is associated with damage to the anterior cingulate gyrus, which is part of the mesial frontal system in the brain. In clinical practice, abulia generally refers to patients who are fully awake but otherwise severely impaired in their ability to communicate
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