Singapore: Antidepressant market in US, that peaked at USD12 billion in 2008, has lost USD2.6 billion due to expired patents in the following years and currently stands at USD9.4 billion, declining on an average of 4 percent per year, according to analysis firm Research and Market.

Currently, generics control over 40 percent of the market in terms of revenue and over 85 percent of the market in terms of prescriptions. Any change in price mix through adding a premium price markup for a growing brand could re-ignite growth in the market.

Branded pharmaceutical companies are increasingly pulling out the antidepressant market, despite widespread use of the medication, as patent expiry and new drug development failures make it unprofitable to remain in the market.

With its naturally fluctuating course, depression is a highly placebo-responsive condition. Mean placebo response rates in antidepressant clinical trials hover around the 35 percent level. Physician-patient relationship, socio-cultural background, the treatment situation set and setting and even the color and shape of the placebo pill are contributing factors to the placebo response.

Research and Market mentions that a dependable brand name also evokes an inherent response in the depressed patient. With billions of dollars already invested in developing antidepressant brands over the past two decades, finding a way to measure such response and to reliably measure its true effect can offer some of those valuable brands a new lease on life.