Single session depression intervention adapted for youth with T1D. The T1D-specific depression SSI will include 1) psychoeducation about depression, including how behavior shapes feelings and thoughts, 2) a values assessment, where youth will identify key areas (i.e., family relationships, friendships, school, or hobbies) from which they draw (or once drew) enjoyment and meaning, and 3) the creation of an activity action plan, wherein youth identify (from pre-generated lists) and personalize (in guided exercises) three activities to target for change.

Educational material about T1D

The T1D-specific depression SSI will include 1) psychoeducation about depression, including how behavior shapes feelings and thoughts, 2) a values assessment, where youth will identify key areas (i.e., family relationships, friendships, school, or hobbies) from which they draw (or once drew) enjoyment and meaning, and 3) the creation of an activity action plan, wherein youth identify (from pre-generated lists) and personalize (in guided exercises) three activities to target for change.

Proxy measure of glycemic level. HbA1c is the average blood glucose level over 3-4 months. We will use fingerstick blood samples and a valid mail-in dried blood spot kit to measure participant HbA1c levels at a central laboratory

The PHQ-9 is a well-validated and reliable measure that assesses the occurrence of nine possible depressive symptoms over the previous two weeks. Higher scores indicate greater depressive symptoms. A cut-off score of >5 will be used to characterize elevated depressive symptoms

The PANAS is a 20-item measure that assesses different feelings and emotions. Items are grouped into the two subscales with 10 items each: positive affect and negative affect, with higher scores on the Positive Affect subscale indicating greater intensity of positive emotions, and higher scores on the Negative Affect subscale indicating greater intensity of negative emotions.

The MFQ is a 13-item measure that assesses depressed mood in youth. Higher scores indicate higher depressed mood.

We will determine feasibility by calculating study enrollment rates for the Aim 2 pilot trial. We will also assess the feasibility of the type 1 diabetes (T1D)-specific depression single-session intervention (SSI) in the qualitative interviews

The PAID-T is a 26-item measure that assesses diabetes-specific emotional distress in adolescents with T1D. Adolescents rate how much each item applies to them on a 6-point Likert scale from 1 (Not a Problem) to 6 (Serious Problem), with higher scores indicating greater distress.