Major opportunities for drug development are being presented in the unipolar depression market, a new report suggests.

The study, conducted by Decision Resources, advises that pharmaceutical firms should tap into this market due to the "high prevalence" of depressive disorders in the world’s major pharmaceutical markets, as well as low patient response rate, with more than one-third of depression patients not responding to first-line antidepressants.

Decision Resources analyst Dr Alana Simorellis said; "Agents that offer faster and more sustained effect than currently available agents or that demonstrate efficacy for treatment-resistant depression would be differentiated in the unipolar depression market."

Simorellis noted, however, that the growing number of generic products will make it "increasingly difficult" for marketers to gain blockbuster status for branded emerging therapies.

The unipolar depression market is set to decrease from $12.3bn in 2011 to just under $10bn in 2021, mainly as a result of generic erosion of key agents, particularly in the US.

The report, entitled ‘Unipolar Depression’ also finds that Bristol Myers Squibb Otsuka Pharmaceutical’s Abilify and AstraZeneca‘s Seroquel continue to modestly increase their patient share as adjunctive treatments for major depressive disorder.

Decision Resources noted that through 2015, sales of the atypical antipsychotic drug class for the treatment of unipolar depression will reach more than $2.5bn in the US, France, Germany, Italy, Spain, the UK and Japan.

Marketers of emerging agents, such as Lundbeck/Takeda’s vortioxetine and Forest Laboratories/Pierre Fabre’s levomilnacipran, are expected to position their therapies as options for patients who have not responded to first-line antidepressants, or in those patients who have residual symptoms of depression, such as fatigue.