**Core Concept**
The relationship between myocardial infarction (MI) and depression is complex, involving bidirectional associations and shared underlying risk factors. Depression is a well-established risk factor for cardiovascular disease, including MI, and individuals with a history of MI are also at increased risk of developing depression. The pathophysiology of this association is multifactorial and may involve inflammation, hypothalamic-pituitary-adrenal axis dysfunction, and alterations in neurotransmitter systems.

**Why the Correct Answer is Right**
The correct answer is D, as it incorrectly states that only cognitive behavioral therapy (CBT) is used after MI. In reality, a range of treatments, including pharmacotherapy with selective serotonin reuptake inhibitors (SSRIs) and CBT, are commonly used to manage depression in patients post-MI. SSRIs, such as fluoxetine and sertraline, have been shown to be effective in reducing symptoms of depression and improving cardiovascular outcomes in patients post-MI. The choice of treatment often depends on individual patient factors, including the severity of depression, presence of comorbid conditions, and patient preferences.

**Why Each Wrong Option is Incorrect**
**Option A:** Depression is indeed a risk factor for MI, as it is associated with increased inflammation, endothelial dysfunction, and other cardiovascular risk factors.
**Option B:** This statement is correct, as MI is a risk factor for depression, likely due to the shared underlying risk factors and the psychological impact of a major cardiovascular event.
**Option C:** This statement is correct, as SSRIs are commonly used in the treatment of depression post-MI, and have been shown to be effective in reducing symptoms of depression and improving cardiovascular outcomes.

**Clinical Pearl / High-Yield Fact**
It is essential for clinicians to recognize the bidirectional relationship between MI and depression, and to consider the psychological impact of a major cardiovascular event when assessing and managing patients post-MI. Early identification and treatment of depression can improve cardiovascular outcomes and reduce the risk of future MI.

**✓ Correct Answer: D. Only cognitive behavioral therapy is used after MI**