Serotonin transporter genotype interacts with paroxetine plasma levels to influence depression treat
Serotonin transporter genotype interacts with paroxetine plasma levels to influence depression treatment response in geriatric patients.
OBJECTIVE: To investigate whether variable antidepressant response may be influenced by an interaction between the serotonin transporter promoter polymorphism (5-HTTLPR) and antidepressant concentration. METHODS: Elderly subjects with depression treated with paroxetine (n = 110) were genotyped and assessed with the Hamilton Rating Scale for Depression (HAMD). A mixed-effect analysis of repeated measures was used. RESULTS: There was an interaction between early paroxetine concentration and 5-HTTLPR genotype on symptomatic improvement over 12 weeks (F(18,59.5) = 1.8, p < 0.05), as well as main effects of both paroxetine concentration (F(68,55.3) = 2.4, p < 0.005) and genotype (F(2,74.2) = 5.7, p < 0.005). Paroxetine concentrations were correlated with change in HAMD scores after 2 weeks of treatment in subjects with the short (s) allele (r = 0.31, p < 0.05) but not in subjects homozygous for the long (l) allele. CONCLUSION: The results demonstrate a concentration-response relation for paroxetine in late-life depression and support the hypothesis for both a direct main effect and a moderating influence of 5-HTTLPR alleles on this concentration-response relation.
Lotrich FE, Pollock BG, Kirshner M, Ferrell RF, Reynolds Iii CF.
Lotrich, Pollock, Kirshner, Reynolds — NIMH Advanced Center in Interventions and Services Research for Late-Life Mood Disorders and the John A. Hartford Foundation Center of Excellence in Geriatric Psychiatry, Department of Psychiatry, Western Psychiatric Institute and Clinics, University of Pittsburgh Medical Center; Ferrell — Department of Human Genetics, University of Pittsburgh, Pittsburgh, Pa.; Pollock — Rotman Research Institute, Baycrest Centre for Geriatric Care, University of Toronto, Toronto, Ont.