An Investigation of the Role of Motivation Level in Producing Placebo Effects in Smokers

It is believed that a variety of psychological mechanisms play a role in producing placebo effects including, but not limited to, expectations, conditioning, and motivation (Finnis et al., 2010). Most research to date has focused on classical conditioning and expectancy explanations, while very few studies have examined how different levels of motivation to respond to a placebo contribute to the placebo effect (Geers et al., 2005; Irmak et al., 2005, Jensen & Karoly, 1991). This study attempted to manipulate the motivation to response to a placebo, or denicotinized (DN), cigarette among regular smokers. Participants smoked a DN cigarette while being randomly assigned to an instructional set manipulation designed to induce low motivation to experience a PE (n=40) or high motivation to experience a PE (n=40). Urge to smoke, mood, nicotine withdrawal, and smoking satisfaction were assessed before and after the manipulation. Smokers in the high motivation group reported significantly greater urge and withdrawal reduction, and greater smoking satisfaction and reward than those in the low motivation group. These findings are among the first to empirically demonstrate that motivation may play a role in placebo responding, and should be explored in future studies.