Background: This study examines comorbidity of posttraumatic stress disorder (PTSD) and depression following myocardial infarction (MI). It has two aims: (a) to examine whether this comorbidity is predicted by the objective severity of the MI and the patients' initial appraisal and stress responses; and (b) to determine whether this comorbidity is associated with PTSD symptomatology, depression, physiological adjustment, and psychosocial adjustment seven months post-MI.
Method: 116 MI patients were examined twice. At Time 1, within a week of the MI, initial appraisal, stress responses, and depressive reactions were assessed, and medical measures were obtained from patients' hospital records. At Time 2, seven months later, PTSD, depression, psychosocial functioning, and physical adjustment were assessed.
Results: Seven months post-MI, 16% of the patients were identified with PTSD; 8% with comorbid PTSD and depression; and 14% with high levels of depression without full PTSD. Initial level of depression was associated with comorbidity of PTSD and depression. While initial stress reactions did not predict comorbidity, they did predict depression, with or without comorbid PTSD. Comorbidity of PTSD and depression was associated with higher levels of adjustment difficulties.
Discussion: Comorbidity of PTSD and depression has some clinical significance. While initial level of depression predicts subsequent comorbidity of PTSD and depression, early stress reactions do not differentiate between MI patients who suffer from depression, with or without comorbid PTSD.