Lower Serum Uric Acid Is Associated With Post-Stroke Depression at Discharge

Poststroke depression (PSD) has been recognized by psychiatrists for more than 100 years, but controlled systematic studies did not begin until the 1970s. Meta-analyses addressing almost all major clinical issues in the field have emerged because of the relatively small number of patients included in some stroke studies. In order to build large databases, these meta-analyses have merged patients with rigorously assessed mood disorders with major depressive features with patients scoring above arbitrary cutoff points on depression rating scales, thus missing important findings such as cognitive impairment associated with major but not minor depression. Nevertheless, PSD occurs in a significant number of patients and constitutes an important complication of stroke, leading to greater disability as well as increased mortality. The most clinically important advances, however, have been in the treatment and prevention of PSD. Recent meta-analyses of randomized controlled trials for the treatment of PSD have demonstrated the efficacy of antidepressants. Similarly, randomized controlled trials for prevention of PSD have shown that antidepressants significantly decrease the incidence of PSD compared with placebo. Early antidepressant treatment of PSD appears to enhance both physical and cognitive recovery from stroke and might increase survival up to 10 years following stroke. There has also been progress in understanding the pathophysiology of PSD. Inflammatory processes might be associated with the onset of at least some depressive symptoms. In addition, genetic and epigenetic variations, white matter disease, cerebrovascular deregulation, altered neuroplasticity, and changes in glutamate neurotransmission might be relevant etiological factors. Further elucidation of the mechanism of PSD may ultimately lead to specific targeted treatments.

In some patients with major depressive disorder (MDD), individual illness characteristics appear consistent with those of a neuroprogressive illness. Features of neuroprogression include poorer symptomatic, treatment and functional outcomes in patients with earlier disease onset and increased number and length of depressive episodes. In such patients, longer and more frequent depressive episodes appear to increase vulnerability for further episodes, precipitating an accelerating and progressive illness course leading to functional decline. Evidence from clinical, biochemical and neuroimaging studies appear to support this model and are informing novel therapeutic approaches. This paper reviews current knowledge of the neuroprogressive processes that may occur in MDD, including structural brain consequences and potential molecular mechanisms including the role of neurotransmitter systems, inflammatory, oxidative and nitrosative stress pathways, neurotrophins and regulation of neurogenesis, cortisol and the hypothalamic-pituitary-adrenal axis modulation, mitochondrial dysfunction and epigenetic and dietary influences. Evidence-based novel treatments informed by this knowledge are discussed.