ABSTRACT: Depression is one of the most common psychological problems affecting individuals with type 1 diabetes, and it is associated with treatment nonadherence and worse clinical outcomes. The research on treating depression or nonadherence in adults with type 1 diabetes is limited. We adapted an evidence-supported treatment, individual cognitive-behavioral therapy for adherence and depression (CBT-AD), for type 1 diabetes and examined its feasibility, acceptability, and potential for an effect.The pilot study included 9 patients with a DSM-IV diagnosis of major depression, dysthymia, or residual depressive symptoms despite treatment with an antidepressant; a diagnosis of type 1 diabetes per patient self-report; and a glycosylated hemoglobin A1c (HbA1c) level of 8.0% or greater. Patients were referred by their diabetes care providers to a behavioral medicine specialty setting and received 10 to 12 sessions of CBT-AD. Main outcome measures included percent of eligible participants who enrolled in the study, session attendance, independently-rated Montgomery-Asberg Depression Rating Scale (MADRS) score, self-reported adherence to diabetes care activities, and adherence to self-monitoring of blood glucose levels. Data were collected from June 27, 2008, through March 31, 2010.There was a clinically meaningful decrease in depression severity (mean [SD] MADRS score decrease from 26.0 [4.73] to 12.3 [7.37], Cohen d = 2.90), demonstrated improvements in diabetes self-care (increase in blood glucose monitoring from 65.0 [26.72] to 82.7 [22.75], Cohen d = -0.66, and a difference in self-reported percent insulin doses in the past 2 weeks from 77.1 [29.84] to 87.1 [23.6], Cohen d = -0.34), and possible improvement in glycemic control (decrease in HbA1c levels from 9.6 [1.32] to 9.0 [1.04], Cohen d = 0.45).These preliminary results provide evidence for the acceptability, feasibility, and potential utility of CBT-AD for patients with type 1 diabetes and depression.clinicaltrials.gov Identifier: NCT01527981.