Thank you so much for this feedback!  It was incredibly helpful.  

I have one follow-up question.  I would like to report the effect size of my finding from a above. This would be looking at how change in clinical score is associated with a change in connectivity pre vs. post-intervention (seed-to-voxel analysis).  How would I go about doing this?  

I ran a seed-to-voxel (contrast a above) and pulled fisher's scores for individual subjects at pre and post-conditions.  I first subtracted each individual value pre and post values. Then I ran a pearson correlation between pre and post fisher's and change in MADRS scores.  I get a value of ~.95  Is this correct useful effect size of the relatinship between change in connectivity and change in a clinical score pre and post intervention?