A radical idea suggests mental health conditions have a single cause

LIFE can be tough. All of us have experienced nagging worries, anxiety, sadness, low mood and paranoid thoughts. Most of the time this is short-lived. But when it persists or worsens, our lives can quickly unravel.

Mental health conditions, including everything from depression and phobias to anorexia and schizophrenia, are shockingly common. In the UK, one in four people experience them each year, so it is likely that you, or someone you know, has sought help from a professional. That process usually begins with a diagnosis – a mental health professional evaluates your symptoms and determines which of the hundreds of conditions listed in psychiatry’s classification bible, the Diagnostic and Statistical Manual of Mental Disorders, best fits. Then you start on a treatment tailored to your condition. It seems an obvious approach, but is it the right one? “For millennia, we’ve put all these psychiatric conditions in separate corners,” says neuroscientist Anke Hammerschlag at Vrije University Amsterdam, the Netherlands. “But maybe that’s not how it works biologically.”

There is growing and compelling evidence that she is correct. Instead of being separate conditions, many mental health problems appear to share an underlying cause, something researchers now call the “p factor”. This realisation could radically change how we diagnose and treat mental health conditions, putting more focus on symptoms instead of labels and offering more general treatments. It also explains puzzling patterns in the occurrence of these conditions in individuals and families. Rethinking mental health this way could be revolutionary: “I don’t think there are such things as [discrete] mental disorders,” says behavioural geneticist Robert Plomin at King’s College London. “They’re just…