Comorbid anxiety disorder in late life depression: Association with memory decline over four years

Objective: In elderly persons with Major Depressive Disorder (MDD), coexisting Generalized Anxiety Disorder (GAD) or Panic Disorder (PD) is associated with more severe symptoms and poorer short-term treatment outcomes. The purpose of this study was to determine whether comorbid GAD or PD was associated with poorer long-term outcomes of late-life MDD, in terms of symptoms, functional disability, and cognitive status. Methods: Seventy-nine older subjects with major depressive disorder who had responded to initial treatment in clinical trials were followed at yearly intervals for up to four years with assessment of their symptoms, cognitive status, and functional disability. For this analysis, subjects were divided into two groups, anxious and non-anxious, based on presence (n = 37) or absence (n = 42) of a lifetime diagnosis of GAD and/or PD. Results: The anxious group showed a greater decline in memory, but not in other cognitive measures or measures of functional status. Depression recurrence was similar in the anxious and non-anxious groups. Among those in the anxious group, a later age of onset ( > 55) of the anxiety disorder was associated with worse overall cognition at baseline, but a similar rate of decline in cognition over time, compared with early-onset anxiety disorder. Conclusion: We found evidence that comorbid GAD or PD is associated with a greater decline in memory in late-life MDD. The data also suggest that anxiety disorders with an onset later in life may be associated with cognitive impairment, although further study is needed to confirm this finding.