Cognitive features in euthymic bipolar patients in old age.
OBJECTIVE
Studies of cognition in bipolar disorder (BD) have reported impairments in processing speed, working memory, episodic memory, and executive function, but they have primarily focused on young and middle-aged adults. In such studies, the severity of cognitive deficits increases with the duration of illness. Therefore, one would expect more pronounced deficits in patients with longstanding BD. The first aim of the present study was to determine the pattern and the magnitude of cognitive impairment in older euthymic BD patients. The second aim was to explore the interrelationship between these cognitive deficits and determine whether they reflect a single core impairment or the co-occurrence of independent cognitive deficits.


METHODS
Twenty-two euthymic elderly BD patients and 22 controls, matched for gender, age, and education, underwent a comprehensive neuropsychological assessment.


RESULTS
Compared to controls, BD patients had significantly reduced performance in processing speed, working memory, verbal fluency, and episodic memory, but not in executive function. Hierarchical regression analyses showed that verbal fluency and working memory impairments were fully mediated by changes in processing speed. This was not the case for the episodic memory dysfunction.


CONCLUSIONS
The cognitive profile in older euthymic BD cases is similar to the one described in younger BD cohorts. Our results further suggest that impaired processing speed plays a major role in the cognitive changes observed in BD patients except for deficits in episodic memory, thus providing strong evidence that processing speed and episodic memory are two core deficits in elderly BD patients.
Delaloye
Christophe
C
Division of Geriatric Psychiatry, University Hospitals of Geneva, Chêne-Bourg, Switzerland.
Moy
Guenaël
G
Baudois
Sandra
S
de Bilbao
Fabienne
F
Remund
Corinne Dubois
CD
Hofer
Françoise
F
Ragno Paquier
Claire
C
Campos
Leticia
L
Weber
Kerstin
K
Gold
Gabriel
G
Moussa
Abba
A
Meiler
Corina Carmen
CC
Giannakopoulos
Panteleimon
P
D000368:Aged; D001714:Bipolar Disorder / Q000150:complications*; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D012044:Regression Analysis