Dysthymia

Who Needs Treatment and How Do We Know?

It is tempting to agree with Barrett and colleagues[1] that dysthymia in primary care is a separate and unique syndrome that requires pharmacologic intervention, though patients with minor depression respond well to watchful waiting. However, this begs the question of who or what are we treating: a patient or a diagnostic label?

We should be concerned about the interpretations of results that encourage the use of labels based on psychiatric diagnosis criteria to drive treatment decisions. These labels confuse the diagnostic criteria's approximation of truth with the concrete truth of a set of symptoms that belong to a patient sitting in the examination room. There is controversy over the validity of diagnostic labels for depressive disorders within the psychiatric literature.[2] In primary care, these problems are amplified because our patients who meet criteria for depressive disorders present with a broad range of severity and frequently have comorbid medical conditions that obscure the unique contribution of depression to the patient's distress.

Despite the best of intentions, the work by Barrett and colleagues links yet another set of diagnostic criteria with an imperative to treat. The results of this study could easily lead to a very different conclusion from the one reached by the authors. The conclusion could have been that response to treatment is dependent on severity and impairment, rather than on satisfying the diagnostic criteria. Because the study's design failed to set an upper limit on the severity of symptoms, the population included severely impaired patients whose response to treatment may have had more to do with that severity than with diagnostic criteria. Indeed, the more severely impaired patients were the ones whose outcomes appear most clinically relevant by showing a significant improvement on the Mental Health Component of the Medical Outcomes Study Short Form 36 health-related quality of life measure.

Their project has 2 other problems that create a challenge in translating the results to routine primary care practice: (1) the use of interventions that require resources not commonly available to a practice, and (2) a lack of longer-term outcome data. Problem Solving Therapy (PST) was designed for delivery by clinicians or staff already present in a typical primary care office in the United Kingdom.(3) Unfortunately, in the study by Barrett and colleagues PST was provided by mental health professionals. This creates a bias in favor of treatment and does not help us understand the effectiveness of PST in a typical primary care practice. In addition, 25-week outcomes were measured as a part of the study protocol but were not reported.[4] These longer-term outcomes would answer questions about treatment sustainability and long-term value.

So, which patients need treatment and how do we determine who they are? Ultimately, the decision is made by those of us who meet with patients in the examination room, listen to their symptoms, attempt to understand their level of impairment, and set priorities among the many comorbid conditions clamoring for attention. Only as a last resort do we reach for a set of diagnostic criteria, hoping they will help us to make sense of the patient's symptoms. The results of the study by Barrett and colleagues should not sway us to a prescriptive mandate for treatment according to the presence of diagnostic criteria. Rather we should prescribe treatment based on each unique patient and his or her level of impairment.

REFERENCES

[1.] Barrett JE, Williams JW, Oxman TE, et al. Treatment of dysthymia and minor depression in primary care: a randomized trial in patients aged 18 to 59 years. J Fam Pract 2001:50:405-12.

[2.] Regier DA, Kaelber CT, Rae DS et al. Limitations of diagnostic criteria and assessment instruments for mental disorders. Implications for research and policy. Arch Gen Psychiatry 1998; 55:109-15.

[3.] Mynors-Wallis L. Problem-solving treatment: evidence for effectiveness and feasibility in primary care. Int J Psychiatry Med 1996; 26:249-62.

[4.] Barrett JE, Williams JW, Jr., Oxman TE, et al. The treatment effectiveness project. A comparison of the effectiveness of paroxetine, problem-solving therapy, and placebo in the treatment of minor depression and dysthymia in primary care patients: background and research plan. Gen Hosp Psychiatry 1999; 21:260-73.

DONALD E. NEASE, JR, MD Ann Arbor, Michigan

(*) All correspondence should be addressed to Donald E. Nease, Jr, MD, Department of Family Medicine, University of Michigan, 1018 Fuller Street, Ann Arbor, MI 48109-0708.

COPYRIGHT 2001 Appleton & Lange
COPYRIGHT 2001 Gale Group