I have the unfortunate feeling that the article's title is indicative of the actual findings. Addiction studies tend to come right out and talk about the pathways and brain activities involved. This one... not so much. :\

Also, 30 people sounds like a very small study.
It is, but it's oddly not that rare a sample size for these minor-topic neurological studies. Maybe it's all the people they can recruit and test on their limited budget? I don't know.