PT  - JOURNAL ARTICLE
AU  - Lotrich, Francis E.
AU  - Pollock, Bruce G.
AU  - Kirshner, Margaret
AU  - Ferrell, Robert F.
AU  - Reynolds, Charles F.
TI  - Serotonin transporter genotype interacts with paroxetine plasma levels to influence depression treatment response in geriatric patients
DP  - 2008 Mar 01
TA  - Journal of Psychiatry and Neuroscience
PG  - 123--130
VI  - 33
IP  - 2
4099  - http://jpn.ca/content/33/2/123.short
4100  - http://jpn.ca/content/33/2/123.full
SO  - JPN2008 Mar 01; 33
AB  - 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 (F18,59.5 = 1.8, p < 0.05), as well as main effects of both paroxetine concentration (F68,55.3 = 2.4, p < 0.005) and genotype (F2,74.2 = 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.