Received Nov. 25, 2008; accepted Feb. 12, 2009. From the Departments of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston (Drs. Weiss and Fava) and the Division of Health Services Research, Partners Psychiatry & Mental Health (Dr. Weiss) Boston, Mass.; and the Department of Psychology, University of Bologna, Bologna, Italy (Dr. Guidi). Financial disclosure appears at the end of the commentary. Corresponding author and reprints: Anthony P. Weiss, M.D., M.B.A., Department of Psychiatry, Massachusetts General Hospital, One Bowdoin Square, Room 734, Boston, MA 02114 (e-mail: aweiss@partners.org). © Copyright 2009 Physicians Postgraduate Press, Inc. here is a well-known gap between the clinical outcomes achieved within randomized controlled T trials (RCTs) and those seen in real-world clinical practice. This phenomenon, sometimes called the “efficacyeffectiveness” gap, has been cited as a potential barrier to achieving optimal benefit from available treatments. The time lag between medical discovery and routine implementation can at times be extraordinarily long (such as the 264-year gap between the first use and the routine use of lemon juice for treatment of scurvy), with current estimates suggesting an average 17-year lapse between initial publication and widespread clinical practice. This pattern has been demonstrated in multiple settings within health care, including psychiatry. One major cause of this gap is the failure to consistently implement those treatments identified as efficacious in RCTs. For example, Wang et al. demonstrated that less than half of all patients treated by mental health specialists received minimally adequate care. Indeed, the rate of concordance with evidence-based mental health care practice may be as low as 10% for certain processes, such as those related to the recognition of and intervention for alcohol use disorders. In addition to these errors of omission, substantial variation in clinical practice has been identified, with rates of antidepressant initiation varying several-fold even among highly similar specialty mental health clinics. To encourage adoption of more consistent, evidencebased treatment practices, a number of disorder-specific guidelines and treatment algorithms have been developed. The goal of these guidelines is to replicate the outcomes achieved in RCTs by advising clinicians to implement those treatments found to be most successful. This approach emphasizes the what; that is, it emphasizes translation of the content of RCTs as being important for improving real-world clinical practice. Even in a guideline-driven practice, however, clinical treatment is often associated with wide variations among practitioners. Clinicians may differ, for example, in how they assess the outcomes of treatment (e.g., symptoms, function, side effects), with clinical impression often used instead of objective symptom assessments, even though the former is less accurate. They may also differ in the degree to which patients are involved in the decisionmaking process, a concept shown to promote greater medication adherence. These differences in the process of care delivery may result in wide variation in outcome, even if the content of that care is consistent. Therefore, while we strongly agree with the importance of translating the content of RCTs to clinical practice, we also believe that clinicians should adopt some of the processes that have been shown to be effective in clinical trials, including routine outcomes measurement and involvement of patients in decision making. This implies translating the how from RCTs to real-world clinical care, something which has received relatively less attention.