Initial Studies

The New Haven - Boston Collaborative Study

• The first major large scale comparative trial of IPT in the treatment of acute depression was the New Haven-Boston Collaborative study conducted by Myrna Weissman and others in 1973¹. This group found that in the short-term treatment of depression, was IPT superior to non-scheduled treatment and equivalent to Amitriptyline, with differential symptom effects The combination of IPT with Amitriptyline was found to be superior to either alone and combination treatment was more acceptable and better tolerated by subjects.

The National Institute of Mental Health Study

• The NIMH Treatment of Depression Study conducted by Elkin and others randomized acutely depressed patients to IPT, CBT, Imipramine and clinical management².

• Using the Hamilton Rating Scale for Depression, IPT was found superior to "placebo" and equal to Imipramine for mild to moderate depression. IPT was slightly more effective than CBT for severe depression (defined as a Hamilton Score over 20).



• The group found no long-term preventive effects for IPT, CBT, or Imipramine at 6, 12, or 18 months.



• Based upon intention to treat, 43% of patients entering IPT achieved remission of depression (defined as a Hamilton Score less than 7) and 55% of patients who completed IPT achieved remission of depression.



• About a quarter of patients terminated prematurely from IPT, all of who were observed to be more severely depressed at intake. The group also noted 33% of patients achieving remission of depression, relapsed within 18 months.

The Pittsburgh Maintenance Therapy with IPT

• An earlier study by Weissman and Klerman had established that 8 months of maintenance antidepressant therapy could prevent relapse of depression, and that maintenance IPT could enhance social functioning, although not for six or so months.



• In the early 1980s Frank and Kupfer's group in Pittsburgh, studied the efficacy of IPT as a maintenance treatment for depression^3,4. After an initial period of treatment with high dose Imipramine and 16 one-hour sessions of IPT, remitted patients were randomized to several treatment conditions.

• Using a survival analysis, Maintenance Imipramine was found to reduce the relapse of depression. IPT-M was not found to be as effective as Imipramine in reducing relapse rates.



• The investigators found that combined treatment with IPT-M and Imipramine did not further reduce relapse.



• IPT-M was found superior to placebo treatment in delaying relapse. This latter finding has inspired research examining the efficacy of IPT-M to for anti-depressant maintenance where drug treatment may wish to be avoided such as pregnancy.

References

1. Weissman MM, Prusoff BA, DiMascio A. The efficacy of drugs and psychotherapy in the treatment of acute depressive episodes. Am J Psychiatry .1979; 136: 555-558.



2. Elkin I, Shea MT, Watkins JT, et al: National Institute of Mental Health Treatment of Depression Collaborative Research Program: general effectiveness of treatments. Archives of General Psychiatry. 1989; 46:971-982.



3. Frank E, Kupfer DJ, Perel JM, et al: Three-year outcomes for maintenance therapies in recurrent depression. Archives of General Psychiatry, 1990;47:1093-1099.



4. Kupfer DJ, Frank E, Perel JM, et al: Five-year outcomes for maintenance therapies in recurrent depression. Archives of General Psychiatry, 1992; 49:769-773.