Clinical Features of Late-Life Depression with Different Biochemical Activity Patterns of Enzymes of Energy, Antioxidant and Glutamate Metabolism

Background : impaired energy metabolism, glutamate and glutathione metabolism contribute differently to the development of late-life depression. The aim was to study the clinical features of depression in groups of elderly patients identi ed by the activity of platelet enzymes of energy and glutamate metabolism and the antioxidant system of glutathione. Patients and Methods : the study included 52 hospitalized patients (40 women and 12 men) aged 60–86 years with a depressive episode of recurrent depressive disorder (RDD), bipolar disorder (BD) and a single depressive episode (DE) on ICD-10 criteria. The study used clinical, psychometric, biochemical and statistical methods. Psychometric assessments were performed before therapy using the Hamilton Depression and Anxiety Scale (HAMD-17, HARS) and the Mini-Mental State Examination (MMSE). At the same day blood samples were taken to determine the activity of cytochrome c-oxidase (COX), glutathione reductase (GR), glutathione S-transferase (GST), and glutamate dehydrogenase (GDH). Results : patients with decreased activity of energy and antioxidant metabolism enzymes (COX, GR, and GST) were characterized by a predominance of shallow apathetic depressions of a “seasonal” nature with mild cognitive impairment, a later age of manifestation, and a high frequency of cerebrovascular pathology. Patients with different changes in enzyme activity (increased COX, decreased GDH and GST) were characterized by an early onset of the disease, its longer duration, more severe and complex depressions with a pronounced anxiety component. Patients with enzyme activity within control values were more likely to have typical melancholy depressions and the lowest frequency of severe cerebrovascular pathology. Conclusion : a relationship was established between the clinical features of late-life depressions and changes in the activity of enzymes of energy, antioxidant, and glutamate metabolism. It was found that patterns of reduced and different enzyme activity correspond to the clinical parameters of late and early-onset depressions. Thus, clinical heterogeneity of late-life depressions is closely related to different biochemical types of metabolism.