Dose-effect relations and responsive regulation of treatment duration: the good enough level

Michael Barkham, Janice Connell, William B Stiles, Jeremy N V Miles, Frank Margison, Chris Evans, John Mellor-Clark

Research output: Contribution to journalArticlepeer-review


This study examined rates of improvement in psychotherapy as a function of the number of sessions attended. The clients (N=1,868; 73.1% female; 92.4% White; average age=40), who were seen for a variety of problems in routine primary care mental health practices, attended 1 to 12 sessions, had planned endings, and completed the Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM) at the beginning and end of their treatment. The percentage of clients achieving reliable and clinically significant improvement (RCSI) on the CORE-OM did not increase with number of sessions attended. Among clients who began treatment above the CORE-OM clinical cutoff (n=1,472), the RCSI rate ranged from 88% for clients who attended 1 session down to 62% for clients who attended 12 sessions (r=-.91). Previously reported negatively accelerating aggregate curves may reflect progressive ending of treatment by clients who had achieved a good enough level of improvement.

Original languageEnglish
Pages (from-to)160-7
Number of pages8
Issue number1
Publication statusPublished - Feb 2006


  • Adaptation, Psychological
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Anxiety Disorders
  • Child
  • Depressive Disorder
  • England
  • Episode of Care
  • Female
  • Humans
  • Male
  • Middle Aged
  • Outcome Assessment (Health Care)
  • Patient Care Planning
  • Personality Assessment
  • Primary Health Care
  • Problem Solving
  • Psychotherapy
  • Quality Assurance, Health Care
  • Statistics as Topic
  • Time Factors

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