Panic! Its Prevalence, Diagnosis and Treatment via the Internet

As evidenced by several trials, cognitive behavior therapy (CBT) is a highly effective treatment for Panic disorder with or without agoraphobia (PD). However, therapists are short in supply, and patients with agoraphobia may not seek therapy due to fear of leaving their homes or traveling certain distances. A major challenge therefore is to increase the accessibility and affordability of evidence-based psychological treatments. This thesis is based on five studies; three treatment studies set up as randomized controlled trails (RCT), one prevalence study, and one study testing the equivalence of an Internet-administered diagnostic assessment tool with a clinician-administered interview. Study I showed that the Swedish 12-month PD prevalence is consistent with findings in most other parts of the Western world (2.2%; CI 95% 1.0%-3.4%). There was a significant sex difference, with a greater prevalence for women (3.6%) compared to men (0.7%). Study II showed that the validity of the computerized diagnostic interview (CIDI-SF) was generally low. However, the agoraphobia and obsessive-compulsive disorder modules had good specificity and sensitivity, respectively. The three RCTs showed, directly or indirectly, that Internet-based self-help is superior to a waiting-list. When 10 individual weekly sessions of CBT for PD was compared with a 10-module self-help program on the Internet, the results suggest that Internet-administered self-help, plus minimal therapist contact via e-mail, is as effective as traditional individual CBT (80% vs. 67% no longer met criteria for panic disorder; composite within-group effect size was Cohen’s d= 0.78 vs. 0.99). One-year follow-up confirmed the results (92% vs. 88% no longer met criteria for panic disorder; d= 0.80 vs. 0.93). The results generally provide evidence to support the continued use and development of Internet-distributed self-help programs