Barriers to Building More Effective Treatments: Negative Interactions Among Smoking-Intervention Components

Meaningfully improved mental and behavioral health treatment is an unrealized dream. Across three factorial experiments, inferential tests in prior studies showed a pattern of negative interactions, suggesting that better clinical outcomes may be obtained when participants receive fewer rather than more intervention components. Furthermore, relatively few significant main effects were found in these experiments. Modeling suggested that negative interactions among components may account for these patterns. In this article, we evaluate factors that may contribute to such declining benefit: increased attentional or effort burden; components that produce their effects via the same capacity-limited mechanisms, making their effects subadditive; and a tipping-point phenomenon in which people near a hypothesized tipping point for change will benefit markedly from weak intervention and people far from the tipping point will benefit little from even strong intervention. New research should explore factors that cause negative interactions among components and constrain the development of more effective treatments.