College students with difficulty falling asleep were
treated with either progressive relaxation, systematic desensitization, or 'a thought .control procedure. All three, treatment groups showed significant lower latency to sleep onset times than a
waiting-list control -group at the end of the three-week treatment
period. A.three-week followup,revealed that All- three treatment
groups' maintained their improvement. The success'of the progressive
relaxation and the systematic desensitization procedures corroborates
earlier evidence while the success of the thought control procedure
suggests' that there may be a cognitive element contributing to
pre-dormitional insomnia.