BackgroundOnly a small proportion of older patients with generalized anxiety disorder (GAD) seek professional help. Difficulties in accessing treatment may contribute to this problem. Guided self-help based on the principles of cognitive-behavioral therapy (GSH-CBT) is one way of promoting access to psychological treatment. Moreover, because the therapist’s role in GSH-CBT is limited to supporting the patient, this role could be assumed by trained and supervised lay providers (LPs) instead of licensed providers. The main goal of this study is to evaluate the efficacy of GSH-CBT guided by LPs for primary threshold or subthreshold GAD in older adults.MethodsWe will conduct a multisite randomized controlled trial comparing an experimental group receiving GSH-CBT guided by LPs (n = 45) to a wait-list control group (n = 45). Treatment will last 15 weeks and will be based on a participant’s manual. Weekly telephone sessions with LPs (30 min maximum) will be limited to providing support. Data will be obtained through clinician evaluations and self-assessment questionnaires. Primary outcomes will be the tendency to worry and severity of GAD symptoms. Secondary outcomes will be anxiety symptoms, sleep difficulties, functional deficit, diagnosis of GAD, and cognitive difficulties. For the experimental group, measurements will take place at pre- and post-treatment and at 6 and 12 months post-treatment. For the control group, three evaluations are planned: two pre-treatment evaluations (before and after the waiting period) and after receiving treatment (post-treatment). The efficacy of GSH-CBT will be established by comparing the change in the two groups on the primary outcomes.DiscussionThis project will provide evidence on the efficacy of a novel approach to treat GAD in older adults. If effective, it could be implemented on a larger scale and provide many older adults with much needed mental health treatment through an expanded workforce.Trial registrationThe trial was registered at ClinicalTrials.gov, number NCT03768544, on December 7, 2018.