Patient adherence with antidepressant treatment

A. C. M. Vergouwen and A. Bakker

Department of Psychiatry, Sint Lucas Andreas Hospital, PO Box 9243, 1006 AE Amsterdam, The Netherlands

In an interesting article, Pampallona et al (2002) reviewed the literature concerning patient adherence in the treatment of depression. The outcome of most studies revealed that interventions to improve adherence tend to be successful in most cases, although it is not completely clear which interventions may be the most helpful.

In our view, the most important goal in trying to enhance adherence is to improve treatment outcome. Pampallona et al stated that ‘the important relationship between adherence and outcome of treatment has been evaluated only in one study’.

When we reviewed the articles that Pampallona et al included in their article, however, we identified at least four studies that addressed the relationship between adherence and treatment outcome.

Katon et al (1995, 1996) demonstrated that multifaceted interventions improved adherence to antidepressant regimens in patients with major and with minor depression. The interventions resulted in more favourable outcomes in patients with major, but not minor, depression. In a more recent study of the same group (Katon et al, 1999) patients in the intervention group also had significantly better adherence to antidepressive medication and showed a significantly greater decrease in severity of depressive symptoms over time and were more likely to have fully recovered during follow-up at 3 and 6 months. Peveler et al (1999) found that counselling about drug treatment significantly improved adherence. Clinical benefit, however, was seen only in patients with major depressive disorder receiving doses >=75 mg of a tricyclic antidepressant.

These findings provide evidence that interventions can enhance adherence and can increase the response rate in patients with major depression who are treated with an adequate dosage of an antidepressant agent. With respect to minor depression results are less convincing.

EDITED BY KHALIDA ISMAIL

REFERENCES

Katon, W., Von Korff, M., Lin, E., et al (1995) Collaborative management to achieve treatment guidelines. Impact on depression in primary care. JAMA, 273, 1026-1031.[Abstract]

Katon, W., Robinson, P., Von Korff, M., et al (1996) A multifaceted intervention to improve treatment of depression in primary care. Archives of General Psychiatry, 53, 924-932.[Abstract]

Katon, W., Von Korff, M., Lin, E., et al (1999) Stepped collaborative care for primary care patients with resistant symptoms of depression. Archives of General Psychiatry, 56, 1109-1115.[Abstract/Free Full Text]

Pampallona, S., Bollini, P., Tibaldi, G., et al (2002) Patient adherence in the treatment of depression. British Journal of Psychiatry, 180, 104-109.[Abstract/Free Full Text]

Peveler, R., George, C., Kinmonth, A.-L., et al (1999) Effect of antidepressant drug counselling and information leaflets on adherence to drug treatment in primary care: randomised controlled trial. BMJ, 319, 612-615.[Abstract/Free Full Text]


 

Authors' reply

S. Pampallona and P. Bollini

for Med Statistics for Medicine, Evolène, Switzerland

G. Tibaldi, B. Kupelnick and C. Munizza

Centro Studi e Ricerche in Psichiatria, Piazza del Donatore di Sangue 3, 10154 Torino, Italy

EDITED BY KHALIDA ISMAIL

The point raised by Mr Lawton-Smith is of the utmost importance, but we found no published randomised studies that considered patients' perspectives as an entry point for interventions to improve compliance. To fill this gap, our group has recently completed a qualitative study involving patients, families and therapists to identify their concerns with adherence and to design effective interventions. We agree with Mr Lawton-Smith that much remains to be done to adapt research methodologies and clinical practices to the needs expressed by people with mental illnesses.

Vergouwen & Bakker incorrectly attribute our statement, ‘the important relationship between adherence and outcome of treatment has been evaluated only in one study’ to randomised interventions, when it referred to descriptive studies, both in the Results and Discussion sections. Out of the 14 randomised interventions we reviewed, only five reported data on response which could be extracted. In addition, the design applied by the five studies made it impossible in our review to explore the relationship between intervention and response.