Cardiac Risk Markers and Response to Depression Treatment in Patients With Coronary Heart Disease.

Background: Depression is associated with an increased risk of mortality in patients with coronary heart disease. There is evidence that this risk may be reduced in patients who respond to depression treatment. The purpose of this study was to determine whether cardiac risk markers predict poor response to depression treatment and, second, whether they improve with successful treatment.

Methods: One hundred fifty-seven patients with stable coronary heart disease who met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for a moderate to severe major depressive episode were treated with cognitive behavior therapy, either alone or combined with an antidepressant, for up to 16 weeks. Depression, physical activity, sleep quality, thyroid hormones (total thyroxine [T4] and free T4), and inflammatory blood markers (C-reactive protein, interleukin-6, tumor necrosis factor) were assessed at baseline and after 16 weeks of treatment.

Results: The mean (SD) Beck Depression Inventory scores were 30.2 (8.5) at baseline and 8.5 (7.8) at 16 weeks. More than 50% of the participants met the criteria for depression remission (17-item Hamilton Rating Scale for Depression ≤ 7) at 16 weeks. Only free T4 thyroid hormone at baseline predicted poor response to depression treatment after adjustment for potential confounders (p = .004). Improvement in sleep quality (p = .012) and physical activity level (p = .041) correlated with improvement in depression. None of the inflammatory markers predicted posttreatment depression or changed with depression.

Conclusions: Thyroid hormone (T4) level predicted depression treatment outcome, and improvement in depression correlated with improvement in sleep and physical activity. More detailed studies of thyroid function and objective assessments of sleep and physical activity in relation to depression improvement and cardiac outcomes are needed.