5 studies on effectiveness of group CBT for HA have formerly been made. They showed treatment effective and acceptable [25,26,29,30], and one study also showed cost-effective for society in saved health care [27]. But the sample sizes of 3 of the studies were small, and their design were not controlled, and for the two RCT studies one began therapy with 8 individual sessions of CBT [30], and the intervention of the second study was mostly psychoeducational [29].