Biological mechanisms have also been associated
Biological mechanisms have also been associated with poor cardiovascular outcomes in ICD patients with depression, such as alteration of cardiac autonomic tone, activation of the sympathetic nervous system, enhanced activity of the hypothalamic-pituitary-adrenal axis, and elevated inflammatory and proinflammatory processes [6,7,10,21]. Although depression is definitely associated with worse outcomes in patients with cardiovascular disease, the pathophysiological mechanisms of this association are not completely understood.
The following additional suspected risk factors and modulators are suggested as markers for the need of psychosocial attention in ICD patients: younger age (<50 years), inadequate knowledge about the cardiac condition or ICD, a significant history of psychological problems, poor social support, and high medical severity or comorbidity . Previous studies have reported that the incidence of depression is generally higher in women than in men [22,23]. Rahmawati et al. revealed that in a cohort study of Japanese patients with an ICD, women had a higher incidence of depression, according to the Beck Depression Inventory, and worried more about their ICD than did men . Therefore, sex may also be a risk factor for depression in ICD patients.
Poor social support is also independently associated with poor cardiovascular outcome . Recently, a longitudinal study of 105 buy SCH727965 failure patients with and without an ICD designed to examine changes in psychosocial status showed that depression increased over time in patients with less initial social support, whereas it did not increase in those with higher initial social support (Fig. 1) .
Kohn et al. found that cognitive behavior therapy (CBT) conducted before implantation, before discharge, and at 7 routine visits decreased depression at the 9-month follow-up in patients with an ICD . In another study, CBT also decreased anxiety and ventricular arrhythmias requiring ICD therapy. However, the effects were limited, and the depressive state of patients did not change over the course of the intervention in this study . The effect of antidepressants such as selective serotonin reuptake inhibitors on the depressive state of ICD patients has not yet been established. Previous studies have suggested that the prevention of ventricular arrhythmia, which requires shock therapy, may be important for alleviating or preventing depression in patients receiving long-term ICD therapy. Increase in social support may also lead to reduction of depression and improvement in health-related QOL in ICD patients with heart failure.
Anxiety Anxiety is common in patients with an ICD and has been reported in 24–87% of patients after ICD implantation. The prevalence of clinically diagnosed anxiety disorder ranges from 13% to 38% [3,29]. The number and frequency of ICD shocks experienced may increase levels of anxiety because an ICD discharge causes fear and pain in some patients. However, a review of the literature reveals that the association between ICD shocks and anxiety is unclear. Some studies have reported a significant relationship between shocks and anxiety [13,30,31], whereas others have found no relationships [32,33], although there have been several limitations such as small numbers of patients. In a study of 308 ICD patients, van den Broek et al. used the State Trait Anxiety Inventory 2 months after implantation and reported that patients who had experienced an ICD shock had a higher level of anxiety than that of patients who had not been subjected to a shock; these researchers suggested that ICD shocks are related to increased levels of anxiety . Moreover, the effect of ICD-related concerns or personality traits on anxiety sensitivity in individuals may be important. A study in 182 ICD patients by Pederson et al. showed that patients who had experienced shocks scored higher on the ICD Patients Concerns Questionnaire and that concerns about ICD (with the upper tertile representing high levels of concern), but not shock, was an independent risk factor for anxiety (according to the Hospital Anxiety and Depression Scale) . A study by van den Broek et al. in 308 ICD patients revealed that type D (according to the 14-item Type D Personality Scale) patients scored higher on the 16-item Anxiety Sensitivity Index than did non-type D patients, and that type D personality and anxiety sensitivity, but not shock, were independent predictors of anxiety . Pedersen et al. also showed that type D personality is associated with increased anxiety in ICD patients [33,35]. Therefore, anxiety in ICD patients does not appear to be simply related to the experience of shocks. Personality traits associated with anxiety sensitivity and ICD-related concerns, as well as the shocks experienced, play important roles in the levels of anxiety in ICD patients.