The complaint has become all too familiar: the phones by our bed are Trojan horses, brimming with enemy soldiers (demands, anxieties, distractions) laying siege to our sleep. The risk of a culture with no off switch is that sleep becomes an inconvenience, an obstacle to the ideal of 24/7 productivity. This is the context for the widely proclaimed insomnia epidemic that, according to sleep scientists such as Matthew Walker, threatens a public health emergency of catastrophic proportions, with dire consequences for our health, safety and productivity.

Few would argue with the basic premise that the digital age is menacing our sleep. But as psychoanalyst Darian Leader’s bracing and important intervention in the debate makes clear, this is a narrow point of agreement amid many points of contention. The most basic concerns the nature of insomnia itself: is it a psychosocial malaise, or a neurobiological one?

The hasty assurance that it is both may be superficially correct, but it’s also disingenuous; most of the contemporary sleep science that determines the parameters of research and leads public discussion of the problem screens out the environmental conditions that shape our sleep, reducing the sleeper to the sum of their neural signals.

Take those research labs that monitor the nocturnal activity of their subjects. Rigidly recumbent on single beds, hooked up to EEGs and other devices, substituting a sterile, anonymous lab for the familiar habitat of their own homes and beds and night-time rituals, the subjects are contrived artefacts of science, resembling ordinary sleepers in much the same way as a Love Island coupling resembles an ordinary relationship. And yet it’s these subjects, Leader notes, whom “we expect to give the real facts about sleep”.

Psychoanalysis has long been accused of lacking scientific precision, ducking the ultimate test of falsifiability and taking refuge instead in untestable speculations. Leader’s example of the sleep lab neatly turns the criticism back on itself – what kind of precision can we expect from measurements that screen out most of the relevant factors?

We sleep next to, down the hall from, or in the felt absence of parents, siblings, lovers, flatmates, whose proximity induces our craving or comfort or disgust. We might be kept awake by the cold, by anxiety that we can’t pay this month’s gas bill, by guilt at having shouted down the complaints of freezing loved ones. There’s no end to the sheer intricacy of the physical, emotional and economic knots in which our sleepless bodies and minds get caught.

It’s impossible, in other words, to extract a discrete biological sleeper from the network of familial, social and economic relations in which sleep and sleeplessness are embedded. But in Leader’s account, this biological reductivism is more than unhelpful; it’s become a symptom of the very malaise it claims to address. He cites the proliferation of ads for the perfect mattress, each ascribing your insomnia to your imperfect one and, in a seemingly deliberate confusion of mattress and soulmate, promising a bed that “remembers” and “contours” itself to the dimensions of your musculoskeletal system. “Your insomnia,” Leader remarks, “is caused less by your worries than by the fact that your mattress is not gold standard.”

In a grimly comic illustration of how the quest for sleep itself becomes a cause of insomnia, we can now spend our sleepless hours on the web, anxiously adjudicating the claims of 12 different mattress brands. Maximising sleep becomes a kind of performative challenge along the lines of (and often related to) maximising productivity. Leader cites the chilling instance of the US insurance giant Aetna, whose 50,000 employees are promised “a bonus for getting more sleep, based on a sleep tracker they can wear”.

Pegged to success and productivity, sleep has become a competitive sport, a prime source of bragging and shaming on social media. As the Aetna example shows, good sleep, supposedly the one irreducibly workless and private region of our lives, is now something we owe to our employers. Insomnia in this model is less an affliction than a personal weakness, something else to feel bad about: “Many people wake to a sense of failure, starting their day with an internal judgement that they have not succeeded in a task, and worrying about how this will affect them.”

Freud’s Interpretation of Dreams, the founding work of psychoanalysis, introduces a conception of the sleeping psyche as the nodal point of unconscious life. Casting the findings of modern sleep science in its light, Leader’s deftly imaginative readings in the book point the way to a richer and more humane understanding of our problems with sleep. He suggests that the most unbearable contents of our dreaming mind might be concealed in Stage 4 NREM (non-REM), the phase of sleep most resistant to waking recall. REM stages of sleep, in contrast, weave the more symbolically intelligible contents of dreams.

The dream that emerges across these phases of sleep is an intricate weave in which impossible desires (incestuous or murderous wishes, for example) form the warp and their symbolic cover stories (often remade in myths and fairytales as well as dreams) the weft. Freud shows us, in other words, the ways in which guilt at our impermissible wishes is perpetually insinuating itself into our dreaming minds, threatening the fragile internal equilibrium of our sleep. The anxieties that keep us from going to sleep share much in this sense with the nightmares that jolt us awake.

Leader persuasively links the sleep-disturbing effects of guilt to a crisis in what he calls “the interpellative, summoning function of language”. Put simply: in order to sleep, we need to switch off the voices urging, rebuking and warning us about everything we should or shouldn’t have done or said or finished or remembered – including, with particularly ticklish irony, the obligation to get an unbroken eight hours. No mattress is going to proof us against those punishing demands.

If any concrete counsel can be inferred from this absorbing and refreshingly sane polemic, it’s that we should ditch the aspiration to turn our sleep into an impregnable fortress, to acknowledge instead its intrinsic fragility. Perhaps we’d manage those passages of wakefulness better if we experienced them less as an enemy than as an integral part of our nocturnal lives.

• Josh Cohen’s Not Working is published by Granta. Why Can’t We Sleep is published by Penguin (£6.99). To order a copy go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £15, online orders only. Phone orders min p&p of £1.99.