The past week has been big for mental illness. As reported last week in this journal, psychiatric researchers have uncovered a spread of genetic clues to schizophrenia, potentially shedding some biochemical light on how this dreadful disease develops. At the same time, a leading US centre for research on mental-health disorders announced a record US$650-million donation from philanthropist Ted Stanley to boost that work (see Nature 511, 393; 2014).

Good news all round. And more could yet follow: genetic understanding of psychiatric disorders, together with more research on the unusual ebb and flow of circuits in the brain, promise a revolution. Researchers of brain disorders compare the current state of their science to knowledge of cancer a decade or so ago, before molecular approaches could stratify patients and select specific treatments.

The latest study on schizophrenia could be a small step forward in this march. Or it could be another false start in a field that has endured more than its fair share. Psychiatric research has yet to provide a single reliable biomarker to aid diagnosis and treatment. Self-reported symptoms and their subjective interpretations remain the basis for clinical diagnosis. Drug companies have walked away. The task of unravelling the biological pathways that drive mental illness, which are needed before drug targets can be identified, has been declared too difficult and too expensive.

Of course, some perspective is needed. Psychiatric research had a long and painful birth. Just a generation or two ago, at a time when physicists had split the atom and biologists were deciphering the structure of DNA, a common treatment for schizophrenia and other mental disorders was a metal spike hammered up through the top of the eye socket and waggled around. With such a history, a lag of a mere decade or so behind cancer research can be taken as a sign of rapid progress.

Whether or not the latest study on the genetics of schizophrenia takes that progress forward, it has already contributed to the public debate around mental illness and public understanding of the issues. It has raised and highlighted the ‘C-word’: cause.

I have obsessive–compulsive disorder (OCD). That used to be a secret, but in April I published a book about the condition and my experiences of it. Despite its frequent portrayal as a behavioural quirk, OCD is a vicious and debilitating mental illness, with some similarities to the experiences of schizophrenia. Simply put, people with OCD can have some of the same dark ideas, thoughts and images as someone with schizophrenia, but the person with OCD is fully aware that they generate the thoughts themselves. (The psychosis that defines schizophrenia is characterized by a lack of such insight, and people with the condition typically attribute the intrusions to an external source.)

“I tell a human story and it is natural to want to know how such stories begin.”

I now give talks about my OCD. A frequent question from the audience is one that I am still ill-prepared to answer: “What caused it?”

I don’t know, and more to the point I don’t care. For 20 years or so I have battled the symptoms. More recently, I sought and received treatment for those symptoms — a high daily dose of the antidepressant sertraline hydrochloride and several months’ worth of weekly sessions of cognitive behavioural therapy. It seemed to work, and without anyone — psychiatrists, psychologists or me — trying to identify the cause.

Perhaps the question from others is down to simple curiosity. I tell a human story and it is natural to want to know how such stories begin. Maybe there is a degree of self-interest because people do not want to follow the path that I did. It could be me who is unusual in not caring about a cause, but when I find out that people have cancer or heart disease or have had a stroke, the cause of their suffering is pretty far down my list of enquiries. In the past two or three years, I have met lots of other people with OCD and other mental disorders. Many of them, like me, do not know and do not seem to care about the who, the where, the why and the when of their illness. There is only how.

The other questions are not sinister. Instead, I think that they reflect an enduring mystery of mental illness. We do not know enough about the mind and the brain to build the backstory. (And as I said earlier, existing treatments do not require it.) Into this unknown creep the myths, the misunderstandings and the agendas. In psycho­analysis, for example, as devised by Sigmund Freud, cause is everything and, sure enough, psychoanalysts usually find a sub­conscious cause for a mental disorder that can be conveniently addressed by — oh, psychoanalysis.

The latest schizophrenia study helps to plug that causation gap. Schizophrenia has problems in the way that it is portrayed in the wider media, but the condition does escape the worst of the trivialization that plagues other forms of mental illness such as depression and OCD. No ignorant and patronizing opinion pieces have been penned in light of these latest developments to claim (as happens with depression, for instance) that the scientists are wrong and that schizophrenia is actually all about societal context and drug-company conspiracy. It is clearly an awful illness, and it — and by extension, other mental disorders — clearly has biological roots.

To expose those roots might lead to new treatments in future, or it might not. Either way, it helps.