Comparisons of PET scans between subjects treated with placebo and fluoxetine showed metabolic increases in the prefrontal cortex, premotor cortex, anterior cingulate, parietal, posterior insula, and posterior cingulate and decreases in the subgingival cingulate , para -hippocampus and thalamus in both groups. The fluoxetine group also had increases in the brainstem and decreases in the striatum, hippocampus and anterior insula and, overall, showed greater changes than the placebo group (Mayberg et al, 2002). This study indicated that while the effects of the placebo might seem the same, additional changes made to the brain by the antidepressant appear to have a longer lasting effect and be more effective in the long term.