Unique single-subject methods

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How are the single-subject methods unique to experimental research? Think of a problem behavior that you might want to improve upon in one of your future clients, and devise a single-subject design to study the effectiveness of your new intervention. Which single-subject approach would you use here (baseline, discrete trials, dynamic), and why?

A single subject experiment is very simple. There is no inherent reason why it should not be accurate, so long as the baseline data is correct. The concept is that a single person, a patient, is diagnosed and given a treatment plan. Prior to the administration of treatment, however, a baseline must be created. This is the condition of the patient for some time prior to the treatment. The baseline substitutes for the "control" group in the singe subject system.

There is a sense that this is inherently behaviorist, but this need not be the case, nor need this be seen as unscientific. All the variables for a real, true experiment are present: baseline data, continuous administration and observation, and then a withdrawal of the treatment. The withdrawal is meant to show that the treatment, not some outside variable, is causing the change in behavior or condition.

The simple AB design is often sufficient. A patient is clearly depressed (in the clinical, not colloquial sense), showing all normal, pathological signs. She is administered an SSRI. After one month, the patient is interviewed. Then again the following month. If things improve, then there is good reason to hold that the SSRI is doing what it should. It would be a huge coincidence if, just at the time the SSRI is administered, the patient gets a promotion at work. These kinds of third variables usually do not have an effect on depression regardless, since depression is not based on external events, but on chemical imbalances (when it is based on external events, it's not "depression" but a rational response to suffering).

Depression is by definition a chemical imbalance, since it occurs powerfully regardless of what else is going on. It is called "logic" or "nature" when it is based on terrible things happening. Once the terrible things go away, the depression will go too, eventually. Yet, of course, this is not a pathological or medical condition at all. We are not speaking of being down in the ...