The goal of this pilot clinical trial is to assess the feasibility of conducting a full-scale study to learn if a new youth-adapted Narrative Enhancement and Cognitive Therapy (NECT-Y) reduces self-stigma in youth living with bipolar disorder or multiple mental health conditions. The main questions it aims to answer are:

• What is the feasibility of conducting a definitive clinical trial in terms of recruitment success, study retention/compliance, treatment retention/compliance, and absence of serious adverse events?
• Can facilitators deliver the adapted NECT-Y intervention with fidelity?
• What is the acceptability of the newly adapted NECT-Y intervention among youth participants and facilitators?

Researchers will compare NECT-Y to treatment as usual (TAU).

Participants will take part in a virtual 14-week NECT-Y group intervention or receive TAU. They will also complete questionnaires at three time points (baseline, post-treatment, and follow-up).

The goal of this pilot basket randomized controlled trial (RCT) is to assess the feasibility of conducting a full-scale study to learn if a youth-adapted Narrative Enhancement and Cognitive Therapy (NECT-Y) can reduce self-stigma in youth diagnosed with bipolar disorder (BD) or with multiple mental health conditions (MMHC). More specifically, this trial has three objectives: 1) to assess whether it is feasible to run a definitive RCT of the new NECT-Y intervention, 2) to explore the facilitators' ability to deliver the new intervention with fidelity, and 3) to assess whether the newly adapted version is acceptable to participants and facilitators, including barriers/facilitators to using NECT-Y.

This parallel-arm pilot basket RCT will be conducted to compare NECT-Y to Treatment as Usual (TAU). The two-arm, pilot RCT will be conducted as two samples within a single basket trial and will include 48 participants with BD and 48 participants with MMHC for a total of approx. 96 participants. Participants will be 1:1 randomized to receive NECT-Y (n=48) or TAU (n=48). Five facilitators, including peer co-facilitators, have been recruited and trained to deliver the intervention.

Participants with BD will be recruited from a clinical pool from outpatient hospital clinics in Toronto (CAMH) and London (LHSC), Ontario, as well as from other CAMH studies if they have provided consent to be re-contacted. Participants with MMHC will be recruited from CAMH only, from among participants recruited to other studies and who have consented to be contacted about additional research opportunities. All participants will follow the same study design. Participants will be screened sequentially during the recruitment period, until the sample size is reached. Eligible participants will complete baseline assessments and then be subsequently randomized to NECT-Y for 14 weeks or TAU. The NECT-Y intervention will be delivered virtually to ≈12 participants/group, with the same number of control participants assigned to TAU. TAU participants will be provided with information on community resources and support, and will also be encouraged to speak to their clinician if they are interested in learning about other services. No study-specific care will be provided to TAU participants. NECT-Y and TAU participants will complete post-treatment assessments after 14 weeks, and again at 3 months follow up. To understand the acceptability of the intervention, qualitative focus groups (approx. 2 hours) will be conducted by the research staff with NECT-Y participants (who consent), and individual interviews will be conducted with the NECT-Y facilitators and peer co-facilitators. Participants randomized to TAU will not receive NECT-Y after the 14-week period as this is beyond the scope of this pilot trial.

This is a youth-engaged mixed methods pilot acceptability and feasibility RCT, with the qualitative component embedded at the post-treatment follow-up stage. Evaluation will include baseline, post-treatment, and 3-month follow-up, feasibility metrics, interpreted together with the themes generated from qualitative focus groups/interviews conducted with participants and facilitators. Lived experience team members will be involved in all stages, from study design to knowledge translation, as co-investigators and a youth advisory group.

Inclusion Criteria:

• Primary diagnosis of bipolar disorder (any subtype) OR diagnosed with multiple mental health conditions (excluding bipolar disorder)
• 'Mild' to 'severe' internalized stigma (mean score > 2.0 on the Internalized Stigma of Mental Illness Inventory)
• Must sign and date the informed consent form
• Stated willingness to comply with all study procedures

Exclusion Criteria:

• Mental health-related hospitalization or emergency department visit in the last 30 days
• Initiation of a new psychotherapy in the last 30 days
• Inability to consent or to communicate in English

Data will be placed in a local brain health data bank following institutional requirements.

Data analysts will be masked as to treatment arms.