Drug Therapy for Generalized Anxiety Disorder Among the Elderly

This study will determine the efficacy of escitalopram (Lexapro®), an anti-anxiety drug, for generalized anxiety disorder (GAD) and the ways genetics affect response to treatment for GAD in elderly individuals.

GAD is a serious public health issue; particularly among the elderly, prevalence of the condition is high, and functional burden on those with the illness is significant. GAD is associated with irregular levels of neurotransmitters, chemicals that carry messages across nerve endings. Serotonin is a neurotransmitter that helps regulate mood and emotions; increased levels of serotonin have been shown to reduce anxiety. Standard treatment for GAD typically involves selective serotonin reuptake inhibitors (SSRIs), drugs that reduce serotonin re-entry into nerve cells. Escitalopram is an SSRI that is well tolerated and highly specific for the serotonin transporter (SERT). The primary aim of this study is to examine the efficacy of escitalopram in reducing anxiety symptoms among elderly GAD patients. Additional aims include examining the efficacy of escitalopram for improving function, quality of life, and neuropsychological functioning, and examining whether genetic variation in the SERT gene influences these participants' response to treatment. Participants will be randomly assigned to receive either escitalopram or placebo for 12 weeks (there is also a 12 week open label extension in which all participants will receive escitalopram). Participants will have weekly/biweekly study visits; during these visits, participants will complete self-report questionnaires on functional ability and anxiety symptoms. Blood collection and cognitive testing through various tasks will also occur.

Participants will either take 10 to 20 mg of escitalopram or placebo. Participants who wish to participate in the open-label extension receive an additional 12 weeks of escitalopram.

Cumulative incident response of anxiety symptom improvement on CGI-I, with 1 (very much improved) to 2 (much improved) indicated as response. Scores synthesized from anxiety rating scale scores, including Penn State Worry Questionnaire (PSWQ) and Hamilton Anxiety Scale (HamA).

Role -emotional impairment score from the Late-Life Function and Disability Instrument (min score=0, significant impairment; max score=100, no impairment).

Inclusion Criteria: Diagnosis of at least moderately severe generalized anxiety disorder (GAD) Exclusion Criteria: Serious suicide risk or psychiatric instability that would affect study participation Dementia Substance abuse, such as alcoholism, within 6 months prior to study entry Diagnosis of schizophrenia, schizoaffective disorder, delusional disorder, or bipolar disorder Unstable medical conditions that would preclude the use of escitalopram Use of certain psychotropics that can not be safely tapered or discontinued for at least 2 weeks prior to and during the study Use of neuroleptics that are absorbed over a prolonged period of time within 6 weeks prior to study entry

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