New research compares the long-term effect of two different forms of therapy for chronic depression and finds that the benefits of one approach, which experts developed specifically for this form of depression, fade 2 years after the treatment ends.

According to estimates, 3%–6% of people are likely to experience chronic depression at some point during their life. Unlike episodic depression, chronic depression—also known as persistent depressive disorder or dysthymia—is a condition that lasts for 2 years without interruption.

However, it's not just the duration of the condition that separates chronic depression from episodic major depression. Chronic depression significantly interferes with day-to-day activities, raises the risk of suicide, and is more likely to occur alongside other psychiatric disorders. Chronic depression is also likely to be more severe and more difficult to treat than episodic major depression.

In chronic depression, the chances of relapse are higher, so in addition to antidepressants, psychotherapy, or a combination of the two, people with chronic depression need a form of maintenance therapy to ensure that they stay in remission.

So far, the cognitive behavioral analysis system of psychotherapy (CBASP) has been the only type of therapy that experts have designed specifically for treating chronic depression, and several trials that compared it with antidepressants found the approach to be successful.

But, how does CBASP fare in the long term? New research, appearing in the journal Psychotherapy and Psychosomatics, investigates. Elisabeth Schramm, from the department of psychiatry and psychotherapy at the University of Freiburg in Germany, is the lead author of the new study, which compares the benefits of CBASP with those of "supportive psychotherapy" at 1 and 2 years after the end of the treatment.

CBASP benefits fade 2 years after treatment

Some people define CBASP as a form of cognitive behavioral therapy (CBT), but, in addition to behavioral elements, CBASP includes interpersonal, cognitive, and psychodynamic strategies in its approach. In CBASP, the therapist helps the client break down distressing interpersonal interactions and determine crucial points at which said interactions could have evolved in a different way if the client had had a different attitude.

Supportive psychotherapy, on the other hand, focuses on improving the self-esteem, resilience, and adaptability of the individual by encouraging them and offering them help to find practical solutions to new situations that might be distressing.

In the current study, Schramm and colleagues compared the two therapies in a "prospective, multicenter, evaluator-blinded, randomized clinical trial" of 268 people who had just received a diagnosis of chronic depression.

The first treatment consisted of 32 sessions of either CBASP or supportive therapy over 48 weeks. Schramm and team assessed the rate of "well weeks" after 1 and 2 years as the primary outcome. Secondary outcomes included "clinician- and self-rated depressive symptoms, response/remission rates, and quality of life."

The results revealed that although CBASP is more beneficial than supportive therapy after 1 year, this type of therapy loses its effectiveness 1–2 years after completion of the treatment. Schramm and colleagues conclude:

"This suggests the necessity of maintenance treatment for early onset chronically depressed patients remitted with CBASP during the acute therapy phase, as well as the [...] integration of other treatment strategies, including medication for those who did not reach remission."