Patients were recruited from consecutive referrals to a hospital infectious diseases outpatient clinic. All patients aged 18-60 with a major complaint of fatigue were medically assessed by a consultant physician (DW or TP). Those whose symptoms were unexplained by organic disease were reinterviewed by one of us (MS) and a full history and psychiatric diagnostic interview17 completed to determine eligibility for inclusion. The inclusion criteria specified that patients had to meet the "Oxford" criteria for the chronic fatigue syndrome.3 T no clinically significant findings on physical examination or laboratory investigation (full blood count, C reactive protein concentration, biochemical measurements, and thyroxine and thyroid stimulating hormone concentrations). That takes care of any ME patients that could have been present Introduction i THINK THAT ABOUT SAYS IT ALL h SIXTY PATIENTS WITH A POWER OF 80% TOTALLY MEANINGLESS BEFORE WE START DESIGN SO IN ENGLISH: The patients beliefs that their illness was physical was "questioned"b as being to simple(ie wrong) and to to consider a more complex(correct) explanation They were told to increase their level of excercise They were given treatment for the assumed psychological factors involved The patients gave subjective accounts of their activity levels over the last month.features of these accounts were given points and recorded on a scale.I,m sure there was no prompting involved here. So more patient ratings but now asked to walk down a 20 metre corridor! SO IF BELIEFS IN PSYCHOLOGICAL CAUSATION INCREASED THEN PATIENT WAS MAKING PROGRESS 6 THEY PREDEFINED NORMAL FUNCTIONING AS HAVING A KARNOFSKY FUNCTIONING OF 80. NORMAL FUNCTIONING DOES NOT MEAN FUNCTIONING NORMAL NOW IN A GOOD STUDY THE CONFIDENCE INTERVALS WOULD BE NO MORE THAN 5% EITHER SIDE OF THE MEAN.lOOK HOW WIDE THEY ARE HERE AT FIVE MONTHS STANDARD MEDICAL CARE MANAGED TO MAKE SOME PATIENTS WORST AND ONLY GAVE MINIMAL IMPROVEMENT COMPARED TO BASELINE AT 12 MONTHS ONLY 27% OF PATIENTS SHOWED ANY SUBJECTIVE BENEFIT TO MEDICAL TREATMENT 50% SHOWED SOME SUBJECTIVE BENEFIT Distance walked in 6 minutes (m)+ Baseline 424 435 5 467 436 43 1 42 (8 to 76) 8 476 436 52 1 51 (14 to 88) 12 481 437 57 2 55 (17 to 94) +Includes some estimated values. See text. NOW HOW COULD THEY ACCURATELY MEASURE THE WALKING DISTANCES IN THE MEDICAL TREATMENT GROUP BUT HAD TO GUESS THE VALUES IN THE CBT GROUP. WHY WERE THE BASELINE WALKING DISTANCES MORE IN THE CONTROL GROUP CBT ENABLED SOME PATIENTS TO WALK AN ENTIRE 51 METRES FURTHER IN 6 MINUTES BUT WHAT HAPPENED IN THE SIX MINUTES AFTER THAT.THEY STILL WALK FOR ATOTAL TIME OF 6 MINUTES NOTICE NO P VALUES HERE ! this trial cognitive behaviour therapy was both acceptable and more effective than medical care alone in improving patients' day to day functioning in the medium term (though not in the short term). It was also more effective in helping patients to feel better. Though the overall treatment effect was substantial, few patients reported complete resolution of symptoms and not all improved. Predictors of response to cognitive behaviour therapy will be the subject of a separate report. The difference between the treatment groups at the final assessment was clinically important. Not only was the end point on the principal measure (Karnofsky score) predetermined for its clinical significance but similar clinically relevant changes were found on other objective and self rated measures. This difference can also confidently be attributed to the cognitive behaviour therapy, as randomisation achieved well balanced groups at baseline, all patients were included in the analysis, and there were no measurable differences between the groups in the other treatments received. Furthermore, the specificity of the treatment effect was supported by the observation that relevant illness beliefs and coping behaviour changed more in the patients given cognitive behaviour therapy.