2006 issue 1

Back

Volume 15, issue 1

Original article

Neuropsychological evaluation of prefrontal cortex function in patients aged over 50, with depression or mild cognitive impairment

Alina Borkowska1, Agnieszka Kałwa2, Marzena Ziółkowska-Kochan3, Janusz Rybakowski4
1. Zakład Neuropsychologii Klinicznej Uniwersytetu Mikołaja Kopernika w Toruniu, Collegium Medicum w Bydgoszczy
2. Oddział Kliniczny Samodzielnej Pracowni Farmakoterapii Instytutu Psychiatrii i Neurologii w Warszawie
3. Katedra i Zakład Neurofizjologii Uniwersytetu Mikołaja Kopernika w Toruniu, Collegium Medicum w Bydgoszczy
4. Klinika Psychiatrii Dorosłych Akademii Medycznej w Poznaniu
Postępy Psychiatrii i Neurologii 2006; 15 (1): 1-6
Keywords: depression, mild cognitive impairment, cognitive dysfunctions, neuropsychological tests

Abstract

Objectives. The aim of the study was to compare the performance on neuropsychological tests that assess "frontal "functions, in matched groups of patients aged over 50 years, with the diagnosis of either recurrent depression or mild cognitive impairment (MCI).

Methods. Participants in the study were 30 patients with depression in the course of unipolar affective disorder (21 female, 9 male, mean age 55.4 ±4.7 years) and 30 MCI subjects (21 female, 9 male, mean age 61.9 ±5.6 years). The control group were 30 healthy persons (20 female, 10 male, mean age 59.7 ±7.7 years). Depression was assessed using the 17-item Hamilton depression scale, while the Mini Mental State Examination (MMSE) served to estimate global cognitive impairment. Neuropsychological evaluation entailed the following "frontal" tests: the Trail Making Test (TMT), the Stroop test, the Wisconsin Card Sorting Test (WCST) and the N-back test.

Results. Mean depression scores were 23.9 ±3.7 and 4.5 ± 1.4 points in the depressed group and in MCI subjects, respectively, while the MMSE mean scores were 29.1 ±1.3 in depression and 25.3 ±0.9 in MCI subjects. Both depressive and MCI patients' performance on all the neuropsychological tests was significantly inferior to that of healthy controls. The performance on the WCST and N-back test assessing working memory and executive functions was much poorer in the MCI group than in depressive patients.

Conclusions. Using the WCST and the N-back test we demonstrated that depressed patients aged over 50 years had moderate disturbances of frontal functions during the acute episode. On the other hand, MCI patients with no depressive symptoms had severe disturbances offrontal functions measured by these tests, and their impairment was several times more severe than that in depressive patients.

Address for correspondence:
Dr hab. Alina Borkowska
Zakład Neuropsychologii Klinicznej Uniwersytetu Mikołaja Kopernika w Toruniu
Collegium Medicum w Bydgoszczy
ul. Marii Skłodowskiej-Curie 9, 85-094 Bydgoszcz
e-mail: alab@cm.umk.pl