A disabling disease which drains energy out of sufferers is to be tackled with a new online treatment trial of more than 700 children and teenagers.
Those with Chronic Fatigue Syndrome (CFS) have erratic sleeping patterns, experience nausea and headaches, and are persistently left crippled with exhaustion.
Yet, just one in 10 affected children in the UK can access specialist treatment as services are scant - a situation branded a "failure" by leading paediatrician Professor Esther Crawley.
Now, a new clinical trial - the largest of its kind - will follow a successful 2012 version conducted in the Netherlands to find out if online-only home treatment is viable for use on the NHS.
The Dutch study found around two-thirds of patients (63%) had "recovered" using FITNET (Fatigue in Teenagers on the Internet) versus 8% in normal care after six months.
Half of patients will undergo an online treatment dubbed FITNET-NHS. It will see children and parents work through intensive online modules, do homework, make diary entries and have regular therapist appointments through video.
The control group half will use Activity Management. They will be given advice on making sleep and activity changes with some Skype calls from therapists but care will be handed to their local GP.
Professor Crawley, of Bristol University, who is leading the trial, said: "This is not some box-ticking app, it has been tested to death.
"Children with CFS/ME are desperate for specialist treatment and we need to think of new ways to deliver it. It is a failure these children are not being seen."
Most children with the condition - also known as myalgic encephalomyelitis (ME) - will recover if they are treated with specialist methods which change their behaviour around things like exercise, sleep and general activities.
However, a group of activists have raised questions over using psychological treatment for a biological disease.
Professor Crawley said: "There is plenty of evidence now to say this is a real illness. But just because this is not a psychological illness, that does not mean psychological therapy cannot help - that is true throughout medicine."
An unnamed mother of an affected child describes his life as being "confined to our sofa... white as a ghost, with debilitating fatigue, headaches and nausea".
She said: "CFS/ME is a cruel illness... it can give you days when you feel well and 'normal', however, children can often do too much on those days and then pay for it and the 'normality' is snatched away, plunging them back into isolation..."
The study will also analyse: "Fatigue, pain, quality of life, anxiety and depression at three, six, nine and 12 months as well as information on how much the NHS and families spend on treatment and whether parents return to work."
CFS/ME affects around 2% of teenagers. It causes them to miss one year of school on average with around one third developing anxiety and mood problems.
For the trial, 734 volunteers are needed with results expected around 2022.
The study will show which treatment is cost-effective and fit for use on the NHS.
It is being funded by the National Institute for Health Research and the Health Technology Assessment Programme at a cost of around £1 million.
Copyright (c) Press Association Ltd. 2016, All Rights Reserved.