BMC Public Health 2005, 5:75 http://www.biomedcentral.com/1471-2458/5/75 alcoholics who lack social support are more likely to enter or remain in treatment. There are a large number of both positive and negative reasons why alcoholic participants drop out of clinical trials. Positive reasons include work commitments, pregnancy, re-location to another area and remission from drinking. Negative reasons include continued or increased drinking, abuse of other sub- stances, attitude towards the clinical staff or environment, physical illness, hospitalization and incarceration. Conclusions drawn from therapy delivered in clinical tri- als might not be applicable to therapy in other settings. We might well expect great differences in clinical effective- ness between different therapists, and between different treatment programs. However it can be argued that the large non-treatment effect seen in this study is present in other aggregated outcome studies published in the litera- tures. Miller and others [9] presented results from a number of such trials, in addition to Project MATCH. Table 1 summarized their findings for the two outcome variables studied here. The outcomes of the different stud- ies are remarkably similar. The similarity in results would suggest that the non-treatment effect identified here may be present in all these studies. The outcome variables in these analyses were the original primary MATCH outcome variables. We have been able to show that the analyses of these variables, and the treat- ment attendance variable, are in perfect concordance with published analyses of the Project MATCH Research group [20]. Over 60 publications have been generated by Project MATCH, but, to the best of our knowledge, all have over- looked the main finding of this study, i.e., the good out- comes of the zero treatment group when compared to the full treatment group and that the improvement in all groups occurred immediately after enrollment in the trial. Ineffective treatment would be the most parsimonious explanation for the rather surprising main findings of Project MATCH, that there was no match between patient characteristics and different types of treatment, and that all three treatments were equal. There may be similarities between these results, for alco- holism patients, and effects seen in some other types of patients. Depressed patients sometimes report significant improvement after enrolling in clinical trials but before receiving therapy [25]. Recent time-course analyses in depression report sudden decreases in depression regard- less of treatment condition [26]. These rapid responders were associated with better outcome at the end of the treatment and into follow-up [27]. It is difficult to compare the high quality follow-up data of Project MATCH to that in the alcoholism literature, much of which are collected under quite different circum- stances. The zero treatment participants at the final fol- low-up interval (month 15) reported a mean of 25.1 drinks per week, with 45% (35/78) abstinent. These outcomes appear somewhat better than those recently summarized in the literature [17]. Of some 17 studies than included placebo or no treatment conditions, with and without prior detoxification, a mean (for studies) was 21% abstinent, and the average participant was drinking 31 drinks per week [17]. Exaggerated claims of treatment effectiveness can have undesirable consequences for patients, for therapists, and for science. Patients who fail an "effective" treatment may feel even more hopeless. This increased despair may be extremely deleterious in people with such life-threatening habits. Therapists may feel inadequate or frustrated with repeated failures. For science, exaggerated claims tend to shift focus into unproductive directions, and to obscure the pertinent facts that are necessary in order to move the science forward. While this study shows that three of the best treatments currently available for addiction were not very effective, it remains likely that many severely dependent alcoholic individuals benefit from external help. By suggesting practical and helpful ways for dealing with the problems of addiction, therapy may help a patient regain a sense of control over his or her life. We are not suggesting that alcoholism treatment should be discontinued or even reduced. People with alcohol problems clearly need all the help our society can give them. Conclusion These results suggest that current psychosocial treatments for alcoholism are not particularly effective. The improvements in drinking appear to be due to selection effects. Alcoholics who decide to enter treatment are likely to reduce drinking. Those who decrease their drinking are more likely to remain in treatment. Widespread accept- ance of these results would have a profound influence on alcoholism research and treatment because it would shift focus away from treatment components and toward patient characteristics and beliefs. Competing interests The author(s) declare that they have no competing interests. Authors' contributions RBC conceived of the study, participated in drafting the manuscript and performed the statistical analysis. DAF participated in drafting the manuscript. All authors read and approved the final manuscript. Page 10 of 11 (page number not for citation purposes)