Randomized clinical trials are the "golden standard" in testing the efficacy of new treatments. In most of these trials the outcome is often related to emotional distress. Emotional distress is traditionally described as a unitary construct: high distress refers to high levels of negative feelings (e.g., high depressed mood, high sadness) while low distress means a low level of negative feelings (e.g., low depressed mood, low sadness). Indeed, this unitary model of distress is readily seen in current both pharmacological and non-pharmacological studies focused on reducing patient distress (DeRubeis et al., 1999).
However, despite its widespread acceptance, the unitary model of distress has been recently challenged (David et al., 2003). Trying to reduce negative feelings as a whole during stressful events might be inappropriate. Is it adaptive to feel neutral, calm and relaxed during stressful events? Having such neutral feelings is likely to reduce the motivational resources to deal with the stressors. Does one want to reduce negative feelings as a whole, but only to a point that preserves their motivational valence? If so, we are not aware of any research establishing a certain point below which negative feelings should not be reduced, all clinical trials being judged better if distress is as low as possible after the clinical intervention. Moreover, a reduction in distress is not necessarily accompanied by an increase in positive feelings (Bonnano, 2004) and most of the time the increase in positive feelings is not quantified in clinical trials. Thus, the current methodology of clinical trials does not fit "normality" as seen in the real world, but superimposes an artificial one. More precisely, while in the real world "normality" is often defined in terms of positive feelings and/or functional negative feelings when confronted with a stressor, in clinical trials it is defined in a "Vulcanian" way (see "Spock" in Star Trek), with a low level of negative feelings overall. It is curious that, despite this obvious mismatch, the unitary model is still widely used in clinical trials.
Recent data in the field (David et al., 2003) support a (re)conceptualization of distress according to a binary model, in which distress is viewed as consisting of qualitatively different functional (e.g., sadness) and dysfunctional (e.g., depressed mood) negative feelings. Based on these new findings, it is suggested that clinical trials should focus on the reduction of suffering by decreasing dysfunctional negative feelings (e.g., depressed mood) while preserving the motivational resources to deal with the stressor by maintaining functional negative feelings (e. …