The parts of the brain that one would want to stimulate for direct "pleasure hits" are quite deep in the brain and at this point are only reachable [edit: there

The parts of the brain that one would want to stimulate for direct "pleasure hits" are quite deep in the brain and at this point are only reachable [edit: there are some deep focal stimulation techniques under the development, see the other comment in this thread] with a "minimally invasive" operation (relative to other brain surgeries) that still requires several hours of anesthesia, a ~cm hole in your head, a neurosurgeon with ~13 years of post-collegiate training, and ideally an MRI scanner for guidance. For the technique in the parent article - transcranial stimulation - any stimulation of the pleasure centers is incidental and minor. That tDCS seems to have interesting side-effects is still unexplained. There are some ongoing studies of Deep Brain Stimulation with implanted electrodes as a treatment for depression, but it's not a casual thing to undertake.