RELATION OF APATHY TO DEPRESSION, COGNITION, AND DAILY FUNCTION IN DEMENTIA
S.D. Sperry, M.E. Strauss, & A.M. Landes
University Alzheimer Center University Hospitals of Cleveland / Case Western Reserve University Kent State University, Ohio

ABSTRACT

Caregivers of seventy-four older adults with dementia completed a 22 item apathy questionnaire designed to assess changes in initiation, social engagement, and interest since onset of dementia. Caregivers also completed the Blessed Dementia Rating Scale, and the Behavioral Rating Scale for Dementia (BRSD). Cognitive functioning of the older adults with dementia was assessed using the CERAD neuropsychological battery. Patients with dementia were mildly to severely impaired (Mean MMSE = 19.8, range = 3-29). Internal consistency reliability coefficient for the apathy questionnaire was high (.91). Apathy scores were significantly correlated with functional capacity (Blessed Dementia Rating Scale) and disease severity (CDR) (p<.001). Apathy was also significantly related to cognitive functioning of the patient (CERAD verbal fluency (p<.001), naming (p<.01), MMSE (p<.001), and word list learning (p<.05)). Depressive symptoms as assessed by the BRSD were not associated with functional capacity, disease severity, or any of the neuropsychological tests (p>.05). Apathy scores were modestly correlated with depressive symptoms on the BRSD (r =.24, p<.05). Controlling for depression did not materially affect the correlations between apathy and the above neuropsychological measures. These findings support the importance of assessing apathy in dementia as apathy appears to have stronger associations with cognition and functional capacity than do depressive symptoms. Supported by NIA Grant AG08012-12A1.

INTRODUCTION

Apathy is perhaps the most common behavioral change in dementia (Mega, Cummings, Fiorello, and Gornbein, 1996). Apathy is associated with functional limitations (Devanand et al, 1992), and cognitive deficits (Kuzis, Sabe, Tiberti, Dorrego, and Starkstein, 1999). Cognitive deficits are also related to depression in some studies, although these findings are not consistent (Fields, Norman, Straits-Troster, and Troster, 1998). Although there is overlap in the definitions of apathy and depression, current research supports the discrimination of apathy from depression on clinical grounds (Marin, Firinciogullari, and Biedrzycki, 1993).

This study examined the discriminant validity of apathy and depressive symptoms in relation to cognitive and functional status in older adults participating in an Alzheimer disease research registry.

METHODS

PARTICIPANTS

Participants in this study were 74 primary caregivers of older adults who were registrants in the Alzheimer Disease Research Center at Case Western Reserve University / University Hospitals of Cleveland. Most patients involved in the study have been diagnosed with dementia (27 Probable AD; 27 Possible AD; 13 Other dementia; 7 with cognitive and functional changes of uncertain basis).

PROCEDURE

Caregiver informants completed a thirty-minute interview to assess apathy by providing information about the patient's activities, thoughts and feelings. Caregivers also completed an interview to assess mood and behavior of the patient (Behavior Rating Scale for Dementia--BRSD; Tariot et al., 1995), and provided information about the patient's daily living skills (Blessed Dementia Rating Scale--ADLs; Blessed, Tomlinson and Roth, 1968). Patients had completed neuropsychological testing, and were assessed as to diagnosis and severity of illness. All apathy interviews were completed within ninety days of the research visit at which the other measures were obtained.

Apathy interviews were conducted in person or by telephone by an experienced Master's level psychology assistant. The interview contained 22 items to assess changes in apathetic behaviors since onset of memory loss (see sample items below). Depression was assessed with a subscale of the BRSD (see symptoms queried below).

Table 1: Characteristics of Older Adults

N

74

Gender

42 men, 32 women

Age

74.8 years; range = 65- 92.0

Education

13.4; range = 4 - 21

MMSE (N=70; 4 untestable)

19.8; range = 3 - 29.5

CDR

1.53; range = 0.5 - 3
Apathy Scale-- Sample Items

  • Does s/he tend to just sit and do nothing?
  • Will s/he start activities on her/his own?
  • Will s/he start to bathe on her/his own, without reminders or suggestions?
  • Will s/he ask for food or start eating without reminders or suggestions?
  • Are there things that s/he is enthusiastic about?
  • Does s/he show interest in news about friends and family?
  • Once s/he has started an activity, is s/he likely to lose interest in it?
  • Does s/he seem indifferent to what's going on around her/him?
Behavior Rating Scale for Dementia (BRSD) Depression Subscale
  • Feelings of anxiety
  • Sad appearance
  • Hopelessness
  • Crying
  • Guilt feelings
  • Poor self-esteem
  • Feels life is not worth living
  • Feelings of anxiety
  • Sad appearance
  • Hopelessness
  • Crying
  • Guilt feelings
  • Poor self-esteem
  • Feels life is not worth living
RESULTS

Relation of Apathy and Depression to Disease Severity
  • Level of apathy was related (p < .01) to global measures of disease severity (CDR, functional capacity, and MMSE).
  • Depression was not related to disease severity.
  • Depression scores and apathy scores were modestly correlated (p < .05).
  • The correlations between apathy and the disease severity measures, and depression and the disease severity measures were significantly different.
  • The relation of apathy to disease severity was significant even when controlling for depression. (See Table 1).

Table 1: Relation of Apathy and Depression to Global Measures of Disease Severity

APATHY

SCORE

DEPRESSION

SCORE

D r (p < )

PARTIAL r

Controlling for DEPRESSION

CDR (N = 74)

.51**

.18

.01

.43**

Functional Status (N = 74)

.68**

.20

.001

.64**

MMSE (N = 74)

-.44**

.10

.001

-.35**

Depression (N = 74)

.24*

 

**p<.01 *p<.05

RESULTS

Relation of Apathy and Depression to Neuropsychological Measures
  • Level of apathy was related to poorer performance on verbal fluency, naming, and word list learning.
  • Depression was not related to cognitive performance on any of the measures.
  • Correlations between apathy and the cognitive measures, and depression and the cognitive measures, were significantly different for verbal fluency and word list learning, but not naming.
  • The relation of apathy to verbal fluency, naming, and word list learning was significant even when controlling for depression. (See Table 2).

Table 2: Relation of Apathy and Depression to Specific Neuropsychological Measures

APATHY

SCORE

DEPRESSION

SCORE

D r (p < )

PARTIAL r

Controlling for DEPRESSION

Verbal Fluency (N = 73)

-.51**

-.02

.001

-.49**

Naming (N = 73)

-.36**

-.20

.234

-.25*

Word List Learning (N = 66)

-.31*

.12

.01

-.35**

Word List Recall (N = 66)

-.10

.05

Word List Recognition (N = 60)

-.14

.02

Praxis (N = 66)

-.11

-.04

Praxis Recall (N = 66)

-.10

.14

Trails A (N = 60)

.00

.19

Trails B (N = 47)

-.01

-.16

**p<.01 *p<.05

CONCLUSIONS

  • These findings illustrate that, despite some association, apathy and depression can be distinguished from one another in their correlates.
  • Our findings of specific cognitive deficits in association with apathy but not depression is consistent with those of Kuzis et al. (1999), who found apathy to be related to lower scores on verbal fluency, naming, verbal memory, and set shifting.
  • These findings support the importance of assessing apathy in dementia as apathy appears to have stronger associations with cognition and functional capacity than do dysphoric depressive symptoms.
REFERENCES

  • Blessed, G., Tomlinson, B.E., & Roth, M. (1968). The association between quantitative measures of dementia and of senile change in the cerebral grey matter of elderly subjects. British Journal of Psychiatry, 114, 797-811.
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  • Fields, J.A., Norman, S., Straits-Troester, K. A., & Troester, A.I. (1998). The impact of depression on memory in neurodegenerative disease. In: Troester, A.I. (Ed.), Memory in neurodegenerative disease: Biological, cognitive, and clinical perspectives, pp. 314-337. Cambridge University Press: New York, NY.
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Supported by NIA Grant AG08012-12A1