ABSTRACT
OBJECTIVE: While patients with late-life depression (LLD) often exhibit microstructural white matter alterations that can be identified with diffusion tensor imaging (DTI), there is a dearth of information concerning the links between DTI findings and specific cognitive performance, as well as between DTI measures and antidepressant treatment outcomes. DESIGN: Neuroimaging and cognitive tests were conducted at baseline in 71 older adults participating in a larger, 8-week duration antidepressant randomized controlled trial. Correlations between DTI measures of white matter integrity evaluated with tract-based spatial statistics, baseline neurocognitive performance, and prospective antidepressant treatment outcome were evaluated. RESULTS: Fractional anisotropy (FA), an index of white matter integrity, was significantly positively associated with better cognitive function as measured by the Initiation/Perseveration subscale of the Dementia Rating Scale in the bilateral superior longitudinal fasciculus (SLF), bilateral SLF-temporal, and right corticospinal tract (CST). An exploratory analysis limited to these tracts revealed that increased FA in the right CST, right SLF, and right SLF-temporal tracts was correlated with a greater decrease in depressive symptoms. Increased FA in the right CST predicted a greater chance of remission, while increased FA in the right CST and the right SLF predicted a greater chance of treatment response. CONCLUSION: In late-life depression LLD subjects, white matter integrity was positively associated with executive function in white matter tracts which act as key connecting structures underlying the cognitive control network. These tracts may play a role as a positive prognostic factor in antidepressant treatment outcome.
Subject(s)
White Matter , Aged , Anisotropy , Antidepressive Agents/therapeutic use , Brain/diagnostic imaging , Depression/drug therapy , Diffusion Tensor Imaging , Executive Function , Humans , Prospective Studies , Treatment Outcome , White Matter/diagnostic imagingABSTRACT
BACKGROUND: We evaluated factors associated with public drug injection among a cohort of injection drug users (SEOSI) originally recruited from within Vancouver's supervised injecting facility (SIF). METHODS: We used univariate statistics and logistic regression to examine factors associated with public drug injection among SEOSI participants. FINDINGS: Between June 2004 and July 2005, 714 IDU were followed up as part of SEOSI. In multivariate analyses, factors associated with public drug injection included homelessness (adjusted odds ratio (aOR) = 3.10; p < .001), syringe lending (aOR = 5.39; p < .001), requiring help injecting (aOR = 1.60; p = .05), and reporting that wait times affected frequency of SIF use (aOR = 3.26; p < .001). INTERPRETATION: Persistent public injection was independently associated with elevated HIV risk behaviors, as well as programmatic factors that limit SIF use. SIF program expansion may further help to reduce persistent risk behaviors and the community concerns related to public injection drug use.
