Table 2.

Randomized controlled trials reviewed by Ford et al[2] (not including the trials described in Table 1)

Ref.	Country	Sample size	Psychological therapy used
Greene et al[45]	United States	20	CBT
Payne et al[46]	United States	22	CBT
Vollmer et al[48]	United States	34	CBT
Boyce et al[50]	Australia	105	CBT
Drossman et al[44]	United States	169	CBT
Tkachuk et al[47]	Canada	28	CBT
Kennedy et al[49]	England	149	CBT

CBT: Cognitive-behavioral therapy.