In the early 1990s, a series of well-done studies suggested that a lack of social support (eg, living alone or having a small number of close friends) was associated with increased cardiac morbidity and mortality in patients with coronary heart disease. 1 These studies naturally raised the question: Would an increase in social support for patients with low social support reduce their risk of post-myocardial infarction (MI) events? To answer this question, and also to examine the effects of treating depression on subsequent morbidity and mortality in post-MI patients, 2481 depressed or socially isolated men and women were randomized to a psychological intervention or a no-treatment control condition and followed for at least 18 months as part of the recently completed Enhancing Recovery in Coronary Heart Disease (ENRICHD) trial, 1 the largest psychotherapy trial ever conducted.

The results of two related studies are reported in this issue of JCR.2,3 The first report describes the psychometric properties of the ENRICHD Social Support Instrument (ESSI), the instrument designed to screen for low social support and measure outcome of social support in the ENRICHD trial. In developing the ESSI, the investigators were faced with the challenge of designing an instrument to identify individuals with low social support. This required first measuring social support and then establishing a criterion that would be used to screen for "low levels" of social support, a complicated construct involving a number of dimensions, including the size of the social network (eg, number of family, friends), the amount and availability of social interaction (eg, proximity of social networks, marital status, telephone contact), and the availability of "instrumental aid" (eg, care during illness and help with errands, finances, transportation) and emotional support.

The investigators focused on assessing perception rather than actual deficiencies of structural support (presence of a partner), instrumental support (tangible help), and emotional support. Low levels of support were defined by responses indicating little or no support in two or more areas.

The resulting instrument is useful for clinicians and researchers who want to measure this type of support. The ESSI can be completed in a few minutes, is easy to score, and has high test-retest reliability and good convergence with standard emotional support measures. In addition, the large, diverse population enrolled in the ENRICHD trial provides reference values for the ESSI in its use with other populations in other settings.

In the ENRICHD trial, 39% of the patients were depressed; 26% had low social support; and 34% met both criteria. From another standpoint, 47% of the depressed patients had low social support, and 57% of those with low social support were depressed, suggesting that the two conditions are highly comorbid, a finding consistent with a long line of research noting a connection between these two phenomena.

Barefoot et al 3 examined the relation between depression and low social support using a subset of the ENRICHD population, and perhaps as expected, found the interactions to be complicated. High levels of perceived social support scores on the ESSI at baseline were associated with less depression at follow-up assessment. However, there were no associations with other measures of social support. The authors also found that many of the patients identified as depressed in the hospital were no longer depressed a few weeks later. From a practical standpoint, patients with a diagnosis of major depression in the hospital who have low perceived social support require, at the very least, careful follow-up evaluation.

The relation between social support and clinical outcome for post-MI patients has been further complicated by the results of the ENRICHD and another recent trial. In the ENRICHD study, 1 the investigators were faced with the challenge of designing a social support intervention appropriate to the needs of the target population, but had few models of interventions designed specifically to increase social support from which to draw. Nevertheless, for patients enrolled on the basis of low social support, the mean ESSI at 6 months and the mean increase from baseline were significantly higher in the intervention group than in the usual care group, although both groups demonstrated an increase over time and the differences between treatment and control tended to diminish. This finding is at odds with the results of at least one other study, 4 in which social support levels remained stable immediately after an MI and declined during the following year. In the ENRICHD trial, there were no differences between intervention and usual care in the risk of death or nonfatal myocardial infarction for those enrolled on the basis of low social support or for those with low social support and depression.

The importance of social support for post-MI patients also was questioned in a recent study by Frasure-Smith and Lesperance, 5 in which depression, but not perceived social support, was linked to increased long-term cardiac-related mortality after an MI.

Although these latter two studies raise doubts about the importance of social support for cardiovascular disease morbidity and mortality, further analyses of the ENRICHD data may show important relations in subgroups not yet apparent in the main analyses. For instance, do higher scores on the ESSI confirm benefit in some depressed patient groups but not others, or conversely, do lower scores on the ESSI predict a worse outcome in some depressed groups but not others? These negative findings also may be related to the populations studied; to the more aggressive medical management in the current study than in earlier studies; to the frequent assessments that occurred in the usual care group, which may have been reassuring or may have led to behavioral changes; or to many other factors that may have attenuated the previously described relations.

Taken together, these studies suggest that a good measure of social support is available, that social support and depression are related in complicated ways still requiring significant exploration, and that it is possible to change levels of social support with psychotherapy. A major challenge to researchers in this area, therefore, is to design studies and undertake analyses that better identify the benefits and methods of social support intervention. There are many reasons why it is important to help people feel more loved, connected, and emotionally supported. It is no longer possible to be certain, however, that this will help them live longer.

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