Prescribing antidepressants in general practice

Metareview on short-term effectiveness and safety of antidepressants for depression: an evidence-based approach to inform clinical practice

OBJECTIVES

To examine the available scientific literature for answers to clinically relevant questions regarding the effectiveness and tolerability of antidepressant drugs (ADs) for the acute phase treatment of depression and to assess the degree to which the literature supports the findings.

METHODS

We used several sources to identify primary reviews: MEDLINE (1955 to April 2006), EMBASE (1980 to April 2006), PsycINFO (1980 to April 2006), and the Cochrane Library 2006 Issue 1. Additional searches were also carried out on the following databases of the National Health Service Centre for Reviews and Dissemination: Abstracts of Reviews of Effects, Health Technology Assessment, and Turning Research into Practice. We also searched the National Institute of Health and Clinical Excellence guidance website. We carried out a metareview of selected high-quality systematic reviews of short-term pharmacologic interventions with ADs for major depression. To assess efficacy, we followed the hierarchy of evidence proposed by the Centre for Evidence Based Medicine (Oxford), including only reviews of randomized controlled trials. To assess tolerability, we also considered observational data when randomized evidence was not available.

RESULTS

There was randomized evidence that ADs are efficacious in primary care settings and that there may be small, but clinically important, differences in efficacy between ADs. There was no good evidence that an AD combined with an antipsychotic is superior to AD monotherapy in cases of psychotic depression or that intravenous administration leads to more rapid response. There was evidence that monoamine oxidase inhibitors are superior to tricyclic antidepressants, but not to selective serotonin reuptake inhibitors (SSRIs), in treating atypical depression. There is some evidence of harm related to the use of SSRIs in pregnancy but not to their use when breastfeeding. There is evidence that SSRIs may increase suicidal thoughts, but not actual suicide, in early-phase therapy.

CONCLUSIONS

We found a substantial body of evidence regarding the benefits and harms of ADs in the treatment of depressive disorder. Nonetheless, there remains considerable residual uncertainty. The evidence is inadequate for generally applicable recommendations; in most cases, the balance between risks and benefits will need to be considered for individual patients. Clinicians should also be guided by the recommendations and warnings issued by drug regulatory authorities.

Treatment delivery and guidelines in primary care

Because depressive illness is so prevalent, the majority of patients are managed in primary care, without recourse to specialist services. Primary care management is seen to fall short of the standards set in secondary care, but unfortunately there is as yet relatively little evidence from primary care to guide management in this distinctive patient population. Guidelines have been introduced as a means of quality management, and their value in improving care has been assessed in trials. To date, the benefits of the implementation of guidelines have been marginal at best. By contrast, strategies which improve the access of patients to specialist services do seem to be beneficial. There is also evidence that such strategies may be associated with 'cost-offset'. Choice of antidepressant medication for maximum cost benefit should also be informed by an evidence base, which is beginning to be accumulated. Further research on this topic in the primary care context is still needed.