Change in cognitive functioning following acute antidepressant treatment in late-life depression

Abstract

Objective: Selective Serotonin Reuptake Inhibitors (SSRIs) are the most commonly prescribed medications for geriatric depression. The association of late-life depression and cognitive impairment has been well documented. However, there have been few placebo-controlled trials examining the impact of SSRIs on cognitive functioning.

Design: Prepost neuropsychological (NP) data collected as part of an 8-week, double-blind, placebo-controlled trial of citalopram in depressed patients aged 75 years and older were used to examine change in cognitive functioning.

Setting: University-affiliated outpatient psychiatry clinics.

Participants: One hundred seventy-four community-dwelling men and women aged 75 years or older with nonpsychotic unipolar depression.

Measurements: NP assessments included mental status (Mini-Mental State Examination), psychomotor speed (Wechsler Adult Intelligence Scale-III Digit Symbol Subtest), reaction time (Choice Reaction Time), visual-spatial skill (Judgment of Line Orientation), executive functioning (Stroop Color/Word Test), and memory (Buschke Selective Reminding Test).

Results: Differences in the pattern of change by treatment group depended on responder status. Citalopram nonresponders were the only group to decline on verbal learning and psychomotor speed. Citalopram responders showed significant improvement in visuospatial functioning, when compared with nonresponders in either condition, but their improvement was not greater than responders on placebo. Citalopram responders showed greater improvement on psychomotor speed than citalopram nonresponders, but their improvement was not greater than placebo responders or nonresponders.

Conclusions: Medication may have a deleterious effect on some aspects of cognition among patients aged 75 years and older who have not responded. This suggests that patients should not be maintained on a medication if they have not had an adequate response.

Figures

Figure 1

Change in cognitive performance from pre to post-treatment in the (a) placebo condition and (b) citalopram condition across six neuropsychological tests.