A review study from 2009 evaluating the efficiency of cognitive behavioral therapy (CBT) and graded exercise therapy (GET) in myalgic encephalomyelitis (ME) / chronic fatigue syndrome (CFS) confirmed that:
CBT/GET is not only ineffective and not evidence-based, but also potentially harmful for many patients with ME/CFS.
The (bio)psychosocial model of CFS/ME proposed by Harvey and Wessely, has in my opinion been well debunked at this point.
A bio(psychosocial) model based on inflammatory, oxidative and nitrosative stress pathways is more in line with current scientific research.
Based on a wealth of growing evidence, the pathophysiology of chronic fatigue syndrome/myalgic encephalomyelitis is now thought to be largely attributed to abnormalities in inflammatory, immune, oxidative and nitrosative stress pathways, which results in mitochondrial dysfunction and impairments in cellular energy(ATP) production.
In this review, we invalidate the (bio)psychosocial model for ME/CFS and demonstrate that the success claim for CBT/GET to treat ME/CFS is unjust.
CBT/GET is not only hardly more effective than non-interventions or standard medical care, but many patients report that the therapy had affected them adversely, the majority of them even reporting substantial deterioration.
Moreover, this review shows that exertion and thus GET most likely have a negative impact on many ME/CFS patients. Exertion induces post-exertional malaise with a decreased physical performance/aerobic capacity, increased muscoskeletal pain, neurocognitive impairment, “fatigue”, and weakness, and a long lasting “recovery” time.
This can be explained by findings that exertion may amplify pre-existing pathophysiological abnormalities underpinning ME/CFS, such as inflammation, immune dysfunction, oxidative and nitrosative stress, channelopathy, defective stress response mechanisms and a hypoactive hypothalamic-pituitary-adrenal axis.
We conclude that it is unethical to treat patients with ME/CFS with ineffective, non-evidence-based and potentially harmful “rehabilitation therapies”, such as CBT/GET. 
 A review on cognitive behavorial therapy (CBT) and graded exercise therapy (GET) in myalgic encephalomyelitis (ME) / chronic fatigue syndrome (CFS): CBT/GET is not only ineffective and not evidence-based, but also potentially harmful for many patients with ME/CFS.
The information in this article has not been evaluated by the FDA and should not be used to diagnose, cure or treat any disease, implied or otherwise.