A blood test may help the diagnosis and treatment of depression

MAJOR DEPRESSION is a serious illness, but also an elusive one. It wrecks lives and may drive people to suicide. It sometimes, though not always, alternates with periods of mania in a condition called bipolar disorder. And it is disturbingly common. Reliable figures are hard to come by, but in some parts of the world as many as one person in four experiences major depression at some point during their life.Depression’s diagnosis has, though, a worryingly arbitrary quality to it, depending as it does on a doctor’s assessment of a patient’s mood against a checklist of symptoms which may be present in different combinations and are often, in any case, subjective. This has led to a search for reliable biochemical markers of the illness. Not only might these assist diagnosis, they may also improve assessments of prognosis and point towards the most effective treatment in a particular case. Now, a group of neuroscientists at Indiana University, in Indianapolis, led by Alexander Niculescu, think they have found a set of markers that can do all this.