A 90-minute yoga class once a week for 10 weeks reduced paranoid thoughts, memory problems, trouble concentrating, and obsessive thoughts in prison inmates. Other studies have shown that yoga leads to significant improvements in concentration sustained attention and memory and improved ability to control thoughts. Positive results have also been found for yoga practice as a complementary treatment for medication or psychotherapy for General Anxiety Disorder and Obsessive-Compulsive Disorder, including for imprisoned individuals.