Anxiety and depression after acute myocardial infarction: an 18-month follow-up study with repeated measures and comparison with a reference population

BACKGROUND: Recently, there has been substantial improvement in coronary care and a corresponding reduction in mortality after acute myocardial infarction (AMI). Some studies suggest that improved prognosis has led to reduced levels of anxiety and depression after AMI, in both the short and long term. The aims of this study were to assess symptoms of anxiety and depression from the acute event to 18 months following AMI, and to compare results with levels in the Norwegian reference population. DESIGN AND METHODS: The progress of 288 patients was monitored using self-reports 3, 6, 12 and 18 months after AMI. Anxiety and depression were measured by the Hospital Anxiety and Depression Scale. Reference population data were obtained from the Nord-Trøndelag Health Study 1995-1997 (the HUNT 2 Study). RESULTS: At baseline, 19.7 and 13.6% of AMI patients reported high levels of anxiety and depressive symptoms, respectively. At baseline, AMI patients were more anxious, but not more depressed, when compared with the reference population (P<0.001 and P = 0.092, respectively). After 3-18 months, AMI patients' levels of anxiety and depression were not higher than levels in the reference population. Anxiety and depression at baseline and after 3 months were the best predictors of anxiety and depression after 18 months, although complications, bed days and lifestyle improvement also significantly predicted depression after 18 months. CONCLUSION: Initially, AMI patients had higher levels of anxiety, but not depressive symptoms. After 3-18 months, these patients were not more anxious or depressed than the Norwegian reference population.