Early response to selective serotonin reuptake inhibitors in panic disorder is associated with a functional 5-HT1A receptor gene polymorphism

Abstract

BackgroundPanic disorder is a common and disabling condition which can be treated with selective serotonin reuptake inhibitors (SSRIs). Although many subjects respond well to such treatment, there is substantial inter-individual variation implicating genetic factors. Methods102 patients with a diagnosis of panic disorder receiving sertraline or paroxetine took part in study. Hospital Anxiety and Depression Scale score, CGI and panic attack frequency (per month) were assessed before and after 6weeks of SSRI treatment with 1week of titration period. All patients were genotyped for the −1019C/G 5-HT1A receptor and ins/del 5-HT transporter polymorphisms. ResultsThe 5-HT1A receptor −1019C/G polymorphism was strongly associated with response to treatment, in which 20 subjects with the GG genotype showed minimal changes in panic attack frequency with a relative risk of no response of 4.73. This association was also found with each drug independently. However, no association of the ins/del 5-HT transporter polymorphism with treatment response was observed. LimitationsLarger numbers of subjects and longer period of SSRI treatment would confirm and strengthen these preliminary findings. ConclusionThese results indicate the importance of a 5-HT1A receptor gene polymorphism in the response to SSRI treatment of panic disorder.