Update: Barsaglini et al (2013) have recently published a systematic review of neuroimaging findings in psychotherapy studies
In the studies described here, some general caveats apply:
There are few studies of the neural effects of psychotherapy. Most of the available studies have methodological limitations – some common to imaging studies as a group – that constrain the conclusions that can be drawn. These limitations include small sample size, non-random sample, absent or unsatisfactory comparison group, and short duration of treatment, as well as certain limitations of the imaging tasks or parameters and the statistical tests performed.
There are few studies of the neural effects of psychotherapy. Most of the available studies have methodological limitations – some common to imaging studies as a group – that constrain the conclusions that can be drawn. These limitations include small sample size, non-random sample, absent or unsatisfactory comparison group, and short duration of treatment, as well as certain limitations of the imaging tasks or parameters and the statistical tests performed.