Our overall objective is to evaluate the efficacy of therapist-assisted, internet-based cognitive-behavioural therapy (iCBT) for depressed cardiac patients with respect to clinical outcomes, and the feasibility of the program. Our primary outcome will be depression severity; secondary outcomes will be hospitalization for a cardiac cause, recurrent myocardial infarction or revascularization. The study will inform a proposal to incorporate iCBT into the resources routinely available to cardiac patients following hospitalization for a cardiac event.

We are planning we are planning a single-arm, open label trial to evaluate the feasibility, acceptability and efficacy of iCBT among persistently depressed cardiac patients. Cardiac patients will be recruited from inpatient units in a university-affiliated hospital and screened for depression at 4 and possibly 8 or 12 weeks following discharge. Eligible patients will be enrolled in the iCBT program.Data regarding the primary outcome, improvement in depression severity, will be collected at completion of the intervention and at 8 weeks after completion. In addition to depression severity data, we will also obtain other data related to clinical feasibility, such as treatment adherence and the acceptability of the intervention to patients. Self-reported rates of hospital readmission or emergency visits for a cardiac cause will also be tracked.

Inclusion Criteria:

• admitted to one of study units with any cardiac diagnosis OR cardiac procedure on this admission
• able to speak and read English
• able to provide informed consent and participate in therapy
• access to and ability to use a computer with internet access.

Between 4 and 12 weeks after discharge, consenting participants will be required to meet a further inclusion criterion of:

• current depressive symptoms of at least mild severity on 2 successive assessments, 4 weeks apart or a single assessment of mild symptoms at 12 weeks post-discharge.

Exclusion Criteria:

Applied at screening (and criteria 1 and 2 reapplied before enrolment):

1. active suicidal ideation (since this requires immediate referral for intense psychiatric care)
2. previous suicide attempt
3. currently undergoing psychotherapy for depression
4. receiving antidepressant medication that has been initiated or adjusted within previous 3 months
5. concurrent psychiatric disorder, other than anxiety;
6. self-reported substance misuse within past 6 months
7. concurrent terminal illness
8. clinical status interfering with ability to independently engage in iCBT.

We would share all of our de-identified, individual-level data with any credentialed researcher.