1Tyrer, P, Baldwin, D. Generalized anxiety disorder. Lancet 2006; 368: 2156–66.
2Lieb, R, Becker, E, Altamura, C. The epidemiology of generalized anxiety disorder in Europe. Eur Neuropsychopharmacol 2005; 15: 445–52.
3Wittchen, HU. Generalized anxiety disorder: prevalence, burden and cost to society. Depress Anxiety 2002; 16: 162–71.
4Gould, RA, Otto, MW, Pollack, MH, Yap, L. Cognitive-behavioural and pharmacological treatment of generalized anxiety disorder: a preliminary meta-analysis. Behav Ther 1997; 28: 285–305.
5Mitte, K. A meta-analysis of cognitive behavioural treatments for generalized anxiety Disorder: a comparison with pharmacotherapy. Psychol Bull 2005; 131: 785–95.
6Haby, MM, Donnelly, M, Corry, J, Vos, T. Cognitive behavioural therapy for depression, panic disorder and generalised anxiety disorder: a meta-regression of factors that may predict outcome. Aust New Zea J Psychiatry 2006; 40: 9–19.
7Hunot, V, Churchill, R, de Lima, S, Teixeira, V. Psychological therapies for generalized anxiety disorder. Cochrane Database Syst Rev 2007; 1: CD001848.
8Siev, J, Chambless, DL. Specificity of treatment effects: cognitive therapy and relaxation for generalized anxiety and panic disorders. J Consult Clin Psychol 2007; 75: 513–22.
9Covin, R, Ouimet, AJ, Seed, PM, Dozois, DJA. A meta-analysis of CBT for pathological worry among clients with GAD. J Anxiety Dis 2008; 22: 108–16.
10Hanrahan, F, Field, AP, Jones, FW, Davey, GCL. A meta-analysis of cognitive therapy for worry in generalized anxiety disorder. Clin Psychol Rev 2013; 33: 120–32.
11Cuijpers, P, Sijbrandij, M, Koole, S, Huibers, M, Berking, M, Andersson, G. Psychological treatment of generalized anxiety disorder: a meta-analysis. Clin Psychol Rev 2014; 34: 130–40.
12Gonzalves, DC, Byrne, GJ. Interventions for generalized anxiety disorders in older adults: systematic review and meta-analysis. J Anxiety Dis 2012; 26: 1–11.
13Kishita, N, Laidlaw, K. Cognitive behavior therapy for generalized anxiety disorder; Is CBT equally efficacious in adults of working age and older adults? Clin Psychol Rev 2017; 52: 124–36.
14Borkovec, TD, Costello, E. Efficacy of applied relaxation and cognitive-behavioral therapy in the treatment of generalized anxiety disorder. J Consult Clin Psychol 1993; 61: 611–9.
15Borkovec, TD, Ruscio, AM. Psychotherapy for generalized anxiety disorder. J Clin Psychiatry 2001; 62(Suppl): s37–45.
16Fisher, PL. The efficacy of psychological treatments for generalized anxiety disorder? Predictors of treatment outcome. In Worry and its Psychological Disorders: Theory, Assessment and Treatment (ed. Davey, G, Wells, A): 359–77. Wiley, 2006.
17Wells, A. Metacognitive Therapy for Anxiety and Depression. Guilford Press, 2009.
18Wells, A, Welford, M, King, P, Wisely, J, Mendel, E. A pilot randomized trial of metacognitive therapy versus applied relaxation in the treatment of adults with generalized anxiety disorder. Behav Res Ther 2010; 48: 429–34.
19Van der Heiden, C, Muris, P, van der Molen, HT. Randomized controlled trial on the effectiveness of metacognitive therapy and intolerance-of-uncertainty therapy for generalized anxiety disorder. Behav Res Ther 2012; 37: 206–12.
20Di Nardo, PA, Brown, TA, Barlow, DH. Anxiety Disorder Interview Schedule for DSM-IV: Lifetime version (ADIS-IV-L). Oxford University Press, 1994.
21First, MB, Gibbon, M, Spitzer, RL, Williams, JB, Benjamin, L. Structured Clinical Interview for DSM-IV Axis II Personality Disorders (SCID-II). American Psychiatric Association, 1997.
22American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) (4th ed., text rev.). American Psychiatric Association, 2000.
23Meyer, TJ, Miller, ML, Metzger, RL, Borkovec, TD. Development and validation of the Penn State Worry Questionnaire. Behav Res Ther 1990; 28: 487–9.
24Brown, TA, Antony, MM, Barlow, DH. Psychometric properties of the Penn State Worry Questionnaire in a clinical anxiety disorders sample. Behav Res Ther 1992; 30: 33–7.
25Spielberger, CD, Gorsuch, PL, Lushene, RE, Vagg, PR, Jacobs, GA. Manual for the State-Trait Anxiety Inventory. Consulting Psychology Press, 1983.
26Beck, AT, Epstein, N, Brown, G, Steer, RA. An inventory for measuring clinical anxiety: psychometric properties. J Consult Clin Psychol 1988; 56: 893–7.
27Horowitz, LM, Rosenberg, SE, Baer, BA, Ureno, G, Vilasenor, VS. Inventory of interpersonal problems: psychometric properties and clinical applications. J Consult Clin Psychol 1988; 56: 885–92.
28Horvath, AO, Greenberg, LS. Development and validation of the Working Alliance Inventory. J Councel Psychol 1989; 38: 139–49.
29Borkovec, TD, Nau, SD. Credibility of analogue therapy rationales. J Behav The Exp Psychiatry 1972; 3: 257–60.
30Devilly, GJ, Borkovec, TD. Psychometric properties of the Credibility/Expectancy Questionnaire. J Behav The Exp Psychiatry 2000; 31: 73–86.
31Barber, JP, Liese, BS, Adams, MJ. Development of the Cognitive Therapy Adherence and Competency Scale. Psychoter Res 2003; 13: 205–21.
32Nordahl, HM, Wells, A. Metacognitive Therapy Competency Scale (MCT-CS). NTNU University Press, 2009.
33Graham, JW. Missing Data: Analysis and Design. Springer New York, 2012.
34Cohen, J. Statistical Power Analysis for the Behavioral Sciences (2nd edn). Erlbaum, 1988.
35Jacobson, NS, Truax, P. Clinical significance: a statistical approach to defining meaningful change in psychotherapy research. J Consult Clin Psychol 1991; 59: 12–9.
36Molina, S, Borkovec, TD. The Penn State Worry Questionnaire: psychometric properties and associated characteristics. In Worrying: Perspectives on Theory, Assessment and Treatment (ed. Davey, GCL, Tallis, FE): 265–83. Wiley, 1994.
37Borkovec, TD, Castonguay, LG. What is the scientific meaning of ‘empirically supported therapy’? J Consult Clin Psychol 1998; 66: 136–42.