At some point over a long, agonising winter, the writer Horatio Clare went mad. Precisely the moment his hypomania tipped over into psychosis is not clear, but fuelled by cannabis, alcohol, and a punishing work schedule, somewhere in that winter he lost the distinction between fantasy and reality. Party to a global conspiracy of Borgesian complexity, affianced to Kylie Minogue, ringed by invisible snipers, Clare spun out of control.

Heavy Light is Clare’s difficult, compelling account of that time. It is in two parts. The first is a powerful, troubling, at times funny (Kylie Minogue? Really?) descent into madness. It follows, in forensic detail, his increasingly wild antics, the suffering of family and friends as they try to corral and comfort, his 19 days in a psychiatric ward and the hard climb back out to sanity. In the second part he retraces his footsteps, trying to understand how he came to lose his reason. He also gives a flensing account of the limits of our psychiatric knowledge and, despite the passionate commitment of so many carers, the desolate state of mental health services in the UK.

As someone who has suffered not psychosis but depression’s overheated void, I came to Heavy Light with open eyes. During my last tussle with mental illness, I read The Light in the Dark, Clare’s gentle, attentive account of ‘winter blues’, and found company and consolation in his account of that agonising seasonal depletion. But Heavy Light takes us into a different firmament.

Setting to one side the intense personal suffering that mental illness brings, at the heart of our therapeutic approaches lies a conundrum with a philosophical shape. It is something like the mind-brain problem. There is clear evidence that mental disorder can be triggered by experience: trauma, grief, bereavement, they can all pitch us into pathological states. This would suggest that mental illness is a question of meaning, a disruption in the narratives of our lives, that it has to do with our minds not our brains. And yet we also know that mental illness can be triggered by substance abuse, or by direct chemical interference with brain chemistry. Which suggests our brains may be at fault. 

As Clare fights his way through the thickets of psychiatric, psychological, and psychoanalytical approaches to what afflicts him, this two-headed question keeps surfacing. In Clare’s view, Dr X, his consultant while sectioned, is only interested in aberrant brain chemistry. He looks through Clare to his neurotransmitters and offers him a trio of drugs from his threadbare pharmaceutical toolbox to try and fix them. This is the biomedical story of illness and treatment. It is an uncertain, approximate path. As even its adherents acknowledge, little is known for certain either about the causes of mental illness or why the drugs they offer work – although work they do, despite increasing concern among psychiatrists about their long-term impacts. I am no expert here but it looks as if the dopamine hypothesis – that psychosis is linked to dopamine dysregulation – is in trouble, and that best guesses about the origins of mental disorder involve a complex interplay of factors.

On the other hand, and far more congenial to Clare, is the approach taken by his therapist. This traces the roots of mental illness in the deep soil of personal trauma: the shock of early abandonment; a terrified encounter with personal mortality. The job of a therapist is to try and hold the afflicted until they begin to make some peace with their demons and remake the shattered narratives of their lives. This is the therapeutic story of crisis and healing. But as anyone who has dipped a toe into psychoanalytical literature – or its critics – here too, much is uncertain. 

By now, some of you may be spitting through clenched teeth about false dichotomies. And you have my sympathies. Speaking from personal experience, drugs helped lift me from the abyss, but depression always invites me to change the way I live, to get slightly closer to myself, to be that little bit more honest. If you’ll forgive a layman’s daydream, I imagine progress in our understanding of mental affliction involving an overhaul in our concepts of mind and brain. A move to a vision of the brain as a quantum object – a physical object with the quality of mind, an independent consciousness folded into biology.

Although I obviously have skin in this game, I loved Heavy Light: its honesty, its questing intelligence. I loved Clare’s openness to the stories of others – seeking to understand, not to judge. His fellow patients were lucky to have him in their midst. And although I may have questions to ask about his take on the origins of mental illness – questions, not answers – there is one issue on which I cannot fault him. We desperately need to properly fund our mental health services. Clare’s account of his breakdown is one drop in a wide sea of human mental anguish. Although he has nothing but praise for the carers who helped him through, his description of our threadbare mental health services, and the inhuman pressures on those who work in them, is heart-breaking. We have to do better.

Julian Sheather is ethics manager, BMA. The views he expresses in his opinion pieces are entirely his own.

Competing interests: none declared.