Large-group one-session treatment: Feasibility and efficacy in 138 individuals with phobic fear of flying.

Recent research suggests that exposure-based large-group one-session treatments (LG-OSTs) may represent useful and efficient treatment options for different types of phobic fear. Although there are effective single session- and small group-interventions for the treatment of clinically relevant Fear of Flying (FoF), no LG-OST for this type of phobic fear has been realized so far. The present study aimed to investigate feasibility and efficacy of an LG-OST for the treatment of clinically relevant FoF. Two months after an initial diagnostics to assess FoF severity and confirm the underlying diagnoses (89% specific flight phobia; 10% agoraphobia), 138 patients attended the LG-OST consisting of psychoeducation, imparting of a breathing technique and a joint 2 ½ hour exposure flight in a chartered airplane (Airbus A320). FoF again was assessed at pre- and post-treatment as well as at 6-months follow-up with the latter again containing clinical diagnostics. Only a small decrease in FoF emerged in the pre-treatment interval. From pre-to post-treatment however, substantial reductions in FoF were observed with a large mean 'intention-to-treat' effect size of Cohen's d = 1.42 that remained stable over time (mean d = 1.44). At follow-up, 71% of the patients were rated as fully (55%) or partially remitted (16%). Also concerning the treatment of clinically relevant FoF, a LG-OST proved feasible and effective. Therefore, LG-OST can be regarded as a highly efficient and promising treatment tool which in terms of efficiency combines the advantages of one-session individual and group treatments.