Letter by Hasnain and Vieweg Regarding Article, “Myocardial Infarction and Risk of Suicide: A Population-Based Case-Control Study”
To the Editor:
We read with keen interest the study by Larsen et al1 and the accompanying editorial by Williams.2 In a population-based case-control study, Larsen et al1 found that myocardial infarction (MI) was strongly linked to increased risk of suicide; this risk was highest during the first month after patient discharge (adjusted rate ratio, 3.25; 95% confidence interval, 1.61 to 6.56 for patients with no history of psychiatric illness and adjusted rate ratio, 64.05; 95% confidence interval, 13.36 to 307.06 for patients with a history of psychiatric illness) and remained high for at least 5 years after MI. The accompanying editorial2 focused primarily on describing the major intervention trials on depression comorbid with coronary heart disease (CHD). Both the original publication1 and the accompanying editorial2 concluded that the findings by Larsen et al supported the American Heart association (AHA) recommendation3 to screen post-MI patients for depression and suicidal ideation. Previously, we have identified several deficiencies in the AHA guidelines that limit their clinical utility.4 Here, we specifically show why check-list screening for depression following the AHA guidelines would not be the best approach to assess increased suicide risk post-MI.
Depression is an important, but not the only risk factor, for suicide. The strongest risk factors for attempted suicide include mood disorders or other mental disorders, comorbid substance abuse disorders, history of deliberate self harm, and a history of suicide attempts.5 Suicide risk is assessed along a continuum ranging from suicidal ideation alone (relatively less severe) to suicidal ideation with a plan (more severe). Screening for suicide is quite different from screening for depression and uses unique screening instruments that have not been systematically validated to assess suicide risk in primary care (or cardiology) settings.5 We believe any statement implying that screening for depression following the AHA guidelines would screen for suicide can be misleading and can generate a false sense of security.
The AHA guidelines3 suggest initially administering the 2-item Patient Health Questionnaire (PHQ-2) to screen for depression, followed by the 9-item Patient Health Questionnaire (PHQ-9) if the patient responds positively to this initial screen. PHQ-2 does not inquire about suicidal thoughts (one item asks about depression, the other about anhedonia). Obviously, suicidal patients who respond with a “no” to both questions on PHQ-2 would be missed. Those requiring screening with PHQ-9 would be asked about suicidal thoughts (item 9), but there are no data showing that PHQ-9 would be a good suicide screening tool for patients with CHD.
Even if we assume that the AHA screening method would effectively screen for suicide risk among the depressed, when and how often should we screen? Hospital screening would not capture those who become suicidal because of poor coping subsequent to discharge. Screening too close to the MI would also result in many false positives, unnecessarily burdening resources. Two studies on screening for depression in outpatient cardiac settings6,7 found that ≈12% of patients reported suicidal ideas on the PHQ-9. In one of these studies of patients reporting suicidal ideas,7 <4% of suicidal patients required hospitalization for suicidal intent. Data are lacking on how in-patient screening of depression would screen for suicidal patients and impact on resources.
In using the AHA depression screening guidelines to identify suicidal patients, we would also be assuming that post-MI patients would be willing to be screened and would honestly disclose a very personal experience of having suicidal thoughts to a health professional they may or may not have seen before performing a question check-list with them.
Emotional distress is highly prevalent in post-MI patients. In our opinion, a clinical interview by the physician providing cardiac care rather than a question check-list screen would be the best method to assess this vulnerability. The interview would strengthen the clinician-patient relationship, leaving the patient more likely to divulge suicidal intent. The physician would best be able to address the cardiac illness–related concerns contributing to patient distress and provide a forum for continued patient monitoring. From these exchanges, a posthospitalization treatment plan would evolve that could include psychiatric follow-up. The physician may, of course, consult with a psychiatrist at any time during hospitalization. For CHD out-patients, clinical assessment followed by collaborative care may be the best approach to monitor for emotional distress and continuing suicide risk.
In our opinion, unless we start focusing on educating and empowering cardiologists to assess their patients for psychiatric distress clinically, we will need a battery of questionnaires to screen for the conditions and risks significantly associated with CHD including depression,3 suicide,1 and generalized anxiety disorder.8 Those questionnaires still would not replace clinical assessment. The findings of Larsen et al point out the complexity of the problem and a need for further well-designed studies to better understand and effectively address the emotional distress associated with CHD.
Mehrul Hasnain, MD
Department of Psychiatry
Memorial University of Newfoundland
St. John's, NL, Canada
W. Victor R. Vieweg, MD
Departments of Psychiatry and Internal Medicine
Virginia Commonwealth University
- © 2011 American Heart Association, Inc.
- Larsen KK,
- Agerbo E,
- Christensen B,
- Søndergaard J,
- Vestergaard M
- Williams RB
- Lichtman JH,
- Bigger JT Jr.,
- Blumenthal JA,
- Frasure-Smith N,
- Kaufmann PG,
- Lesperance F,
- Mark DB,
- Sheps DS,
- Taylor CB,
- Froelicher ES