Health service providers increasingly need to consider not only the efficacy and safety of a therapy, but also its cost. Our hypothesis was that in our previously reported aripiprazole add-on or switching study, the improved outcomes would be associated with reduced costs. We here report data from this study, now to 52-week follow-up, with 27 total recruits (outpatients partially refractory or intolerant of their current antipsychotic regime). Serial clinical ratings included the Quality of Life Scale and Client Service Receipt Inventory, applied at baseline (N = 24), week 26 (N = 21) and 52 (N = 18). Cost data were unavailable for the drop outs. On last observation carried forward (LOCF) analysis, there was a significant increase in the Quality of Life Scale between baseline and one year (p = 0.007). There were also reductions over time in total direct and indirect costs. For study completers, the total costs at the one-year follow-up period were £ 482 less than those for the corresponding baseline period, with the Quality of Life Scale score at one year being 21.6 points (or 16.4 on LOCF analysis) higher. Therefore, in the completers, improved outcome was associated with reduced costs. Cost-effectiveness could be similarly investigated in a controlled trial.