Internet-based treatment may help teens with chronic fatigue syndrome to recover, researchers have found.

In a study published in Thursday's issue of the medical journal The Lancet, Dutch researchers said more adolescents who received the web-based therapy recovered compared with those who received standard care.

Chronic fatigue syndrome is estimated to affect up to two per cent of people worldwide. It is characterized by persistent tiredness, muscle pain, insomnia and memory problems that last at least six months.

To investigate treatments, Sanne Nijhof from the University Medical Centre in Utrecht and her colleagues randomly assigned 135 students aged 12 to 18 who were diagnosed with chronic fatigue syndrome to individual or group psychotherapy and exercise therapy or a web-based treatment called FitNet.

Of the 67 students in the FitNet group, 50 returned to school full time. In comparison, of the 67 receiving usual care, 10 recovered.

"Internet-based cognitive behavioural therapy was much more effective than was usual care, resulting in higher school attendance, diminished severity of fatigue, improved physical functioning, and better self-rated improvement," the study's authors concluded.

Fitnet resembles the face-to-face counseling of cognitive behavioural therapy to change thinking patterns.

Many therapy sessions

Participants in the Fitnet group were able to log in to a secure site that guaranteed privacy and confidentiality to compose and send e-mails at any time. A therapist responded on a set day once a week and then every two weeks based on an individual treatment plan, and emergency emails received an immediate response.

Parents participated in a parallel program that also included education and the same e-consult application as their children.

After six months, those in the control group were also offered Fitnet.

The researchers said the advantages of web-based treatment included:

Availability at any time.

Avoids barriers such as the inconvenience of travelling to and from a clinician's office.

Reduces treatment time and costs.

The researchers weren't able to tell which aspects of the internet-based therapy were more effective than usual care, but said their findings warrant a cost-benefit assessment.

Peter White of the University of London and Trudie Chalder of the psychological medicine department at King's College London welcomed the accessible and flexible treatment in a journal commentary.

Chronic fatigue is now identified as a common cause of long-term school absence, the commentators said.

Fitnet participants logged on an average of 255 times to the program and emailed the therapists an average of 90 times, which shows the therapeutic dose was large. A previous review suggested the number of therapy sessions contributes to response to cognitive behavioural therapy.

The study's authors also included people who had improved significantly instead of just those who fully recovered, the pair noted in their critique.

To participate in such web-based programs, patients and parents need to be reasonably literate with no language barriers.

The results can't be applied to adults, but internet-based treatments have been used successfully for adults with other health problems, according to the commentary.