Leung and colleagues [93] tested the hypothesis that using gabapentin as an add-on agent for treating postoperative pain reduces the occurrence of postoperative delirium. Patients aged 45 years or older undergoing spine surgery were randomly assigned to gabapentin 900 mg or placebo by mouth 1 to 2 hours before surgery and continued for the first 3 days postoperatively. Postoperative delirium occurred in 0% (0/9) of gabapentin-treated patients and 42% (5/12) of placebo patients (P = 0.045). Reduction in delirium appeared to be due to the opioid-sparing effect of gabapentin. Given the small size of the study, these results require confirmation.