Objective: Executive dysfunction, possibly related to vascular pathology, has been well documented in patients with a first episode of major depressive disorder in later life (late-onset geriatric major depression). However, it is unclear whether the neuropsychological presentation differs in patients with a lifetime history of major depressive disorder (recurrent geriatric major depressive disorder). The purpose of this study was to explore differences in neuropsychological function, symptoms, and cardiovascular comorbidity between patients with late-onset and recurrent geriatric major depression.
Method: The study used a two-by-two factorial design in which one factor was current major depressive disorder (present versus absent) and the second factor was lifetime history of depression (present versus absent). Neuropsychological measures of executive functioning and episodic memory, as well as psychopathological symptoms and comorbid medical illness, were examined in a total of 116 older adults.
Results: Patients with late-onset major depressive disorder showed specific deficits in attention and executive function, whereas patients with recurrent major depressive disorder exhibited deficits in episodic memory. The rates of anhedonia and comorbid cardiovascular illness were higher in patients with late-onset geriatric major depressive disorder.
Conclusions: In contrast to recurrent geriatric major depressive disorder, late-onset major depressive disorder is characterized by specific deficits in tasks of attention and executive function, consistent with increased anhedonia and cardiovascular comorbidity. These findings, if confirmed, suggest that recurrent and late-onset geriatric major depressive disorder may represent distinct phenomenological entities. Such phenomenological differences as a function of lifetime history of major depression can guide research in the neurophysiology, prevention, and treatment of geriatric major depressive disorder.