The Pharmacotherapy and Pharmacoeconomics of Depression

Abstract

Major depression is a potentially life-long mental illness. An episode of depression can last many weeks or months, during which time the patient may suffer disturbance of social relationships, poor work record or inability to work, and possibly be at risk of self-harm, including suicide. Because of the risks associated with depression, the illness needs better recognition by both health professionals and the general public, and a greater understanding that it is an illness that can be treated. Treatment is primarily by pharmacological intervention, rather through the use of psychological therapies (although for mild depression this is more acceptable and appropriate in many cases). This does mean that such treatment should be at a reasonable cost to the health service with good outcomes for patients and healthcare payer alike, as the treatment is likely to be of long duration, possibly for life. In the cost-constrained health service, value for money is paramount. For the patient, the drug chosen should relieve the symptoms of depression with good tolerability. The aim of this study is to assess the relationship between the results of randomised controlled trials of antidepressants and the economics of depression and antidepressants. The pathophysiology of depression and the range of antidepressants available in the UK to treat depressive disorder are reviewed. There is currently a debate regarding the use of antidepressants that have so-called “dual action” as to whether these drugs have greater efficacy than those that have only a single (or predominantly single) mode of action. Randomised controlled trials are the backbone of providing efficacy data, both for licensing approval and subsequently after licensing. However, depression is difficult to measure accurately: there are no ‘hard’ data such as blood pressure measurements. Rating scales are used to assess the level or depth of depression and its progress during drug therapy. In clinical trials they are essential, while in clinical practice they are perhaps less often used. The common rating scales are discussed, focussing particularly on the two most used in clinical trials (the Hamilton Depression Rating Scale and the Montgomery-Asberg Depression Rating Scale). Two chapters review and analyse the literature for the pharmacoeconomics of depression and the use of antidepressants, using a recently introduced drug, escitalopram, as an example of the pharmaceutical industry’s desire to maintain a drug patent, under the pretext of introducing a valuable new addition to the drug armamentarium for treating this potentially serious, enduring illness.