The drop-out rate was too high.

From the scarce literature it showed that computer/internet-aided cognitive behavior therapy (CBT) was superior to waitlist and placebo assignment across outcome measures, and the effects of computer/internet-aided CBT were equal to therapist-delivered treatment across anxiety disorders. The aim of this study is to evidence the effectiveness of internet-based relaxation with biofeedback treatment for panic disorder.

All participants had access to a computer with an internet connection and received the treatment via internet.

Inclusion Criteria:

1. The participant must fulfill DSM-IV criteria for panic disorder.
2. The participant must be between 20 and 60 years of age.
3. The participant must have the Panic Disorder Severity Scale(PDSS) score ≧8.
4. If the participant is taking prescribed drugs for panic disorder, a) the dosage have to be constant for 6 weeks before starting treatment, and b) the participant have to agree to keep the dosage constant for 2 months after starting treatment.
5. If the participant was already in therapy, the contact must have lasted at least 3 months and not be based on cognitive behavior therapy.
6. All participants have access to a computer with an Internet connection.

Exclusion Criteria:

1. The participant suffers from any other psychiatric disorder in immediate need of treatment.
2. The participant fulfills DSM-IV criteria for major depression.
3. The participant has epilepsy, kidney problems, strokes, organic brain syndrome, emphysema, heart disorders, or chronic hypertension.
4. The participant has alcoholism or substance dependence.