The legacy terms “IMPACT Care” or “IMPACT Model” is largely synonymous with Collaborative Care. The terms originate from the IMPACT study, the first large randomized controlled trial of treatment for depression. The IMPACT study demonstrated that Collaborative Care more than doubled the effectiveness of depression treatment for older adults in primary care settings.

The Collaborative Care model (CoCM) is now recognized as effective in treating a wide range of behavioral health disorders – not just depression. A team-based Collaborative Care approach can also address anxiety and trauma disorders, chronic pain, substance use disorders including alcohol and opioids, and ADHD.

In the largest treatment trial for depression to date, a team of researchers led by Dr. Jürgen Unützer followed 1,801 depressed, older adults from 18 diverse primary care clinics across the United States for two years. The 18 participating clinics were associated with eight health care organizations in Washington, California, Texas, Indiana and North Carolina. The clinics included several Health Maintenance Organizations (HMOs), traditional fee-for-service clinics, an Independent Provider Association (IPA), an inner-city public health clinic, and two Veteran’s Administration clinics.

Half of the patients were randomly assigned to receive the care normally available in their primary care clinic, including medications (70% of usual care patients) and/or referral to specialty mental health. The other half of patients were randomly assigned to receive the IMPACT model of depression care, also known as Collaborative Care. A patient registry was developed for the trial that tracked and measured patient goals and clinical outcomes and facilitated treatment adjustment if a patient was not improving as expected.

As reported in JAMA in 2002, Collaborative Care more than doubled the effectiveness of depression treatment for older adults in primary care settings. At 12 months, about half of the patients receiving Collaborative Care reported at least a 50 percent reduction in depressive symptoms, compared with only 19 percent of those in usual care. A handout of usual care versus IMPACT care presents some reasons why the results were as significant as they were. Analysis of data from the survey conducted one year after IMPACT resources were no longer available showed that the benefits of the IMPACT intervention persisted after one year. IMPACT patients experienced more than one hundred additional depression-free days over a two-year period than those treated in usual care.

Since the end of the trial, over one thousand organizations in the United States and internationally have adapted and implemented Collaborative Care with diverse patient populations and for a variety of behavioral health conditions.