The Sexsomnia Loophole
The Dangerous Rise of the Sexsomnia Defence
In the labyrinthine UK justice system, some legal defences are so unusual that they seem almost surreal. “Sexsomnia” - a rare sleep disorder that allegedly causes people to engage in sexual acts while unconscious - is one of them.
Once confined to obscure medical journals, sexsomnia has entered both criminal and family courts with alarming frequency. While genuine cases exist, the growing reliance on the defence, often without robust medical evidence, is raising profound questions about justice, safeguarding, and the balance of rights between the accused and the alleged victim. I know the consequences of this firsthand. In my own rape case, I was told by the Crown Prosecution Service (CPS) that I must have been experiencing sexsomnia - a claim made without a medical diagnosis, without a sleep study, and without even a conversation with a specialist. That explanation was used to justify dropping the case against the man I accused.
What is Sexsomnia?
Sexsomnia is classified as a form of parasomnia - an abnormal behaviour during sleep, similar to sleepwalking or night terrors. It can involve initiating sexual activity without conscious awareness, typically during deep non-REM sleep. It is an acknowledged but rare condition. Medical literature describes it as affecting a tiny proportion of the population, and even then, diagnosis is complex and requires specialist assessment, usually via overnight polysomnography in a clinical setting.
The rarity and diagnostic difficulty create a dangerous opening when sexsomnia is cited in court. Unlike physical evidence such as DNA, it cannot be objectively confirmed without extensive, controlled testing, which is seldom carried out in legal contexts. Currently, in the UK, experts can’t even agree on a diagnostic tool.
The Rise of the Defence
Over the past decade, sexsomnia has been cited more frequently in criminal cases involving allegations of rape or sexual assault, as well as in family court proceedings where safeguarding concerns are at stake. In criminal trials, it is most often used by defendants to claim they were asleep during alleged sexual activity and therefore lacked intent. In some cases, prosecutors themselves have suggested the possibility of sexsomnia to explain away a victim’s account, as happened to me. Family courts face their own version of the problem. Allegations of sexual harm can be undermined if one party claims sexsomnia, introducing doubt about intent or awareness. The result can be decisions that minimise risk and prioritise parental contact over safeguarding, even where professional assessments raise concerns.
My Case
I reported being raped by a man I knew. I expected my account to be taken seriously, investigated thoroughly, and tested in court. Instead, after months of interviews and evidence gathering, I was told the CPS had decided not to prosecute and closed my case 13 days before the trial. Their reasoning was devastating: they concluded that I had been asleep and experiencing sexsomnia during the assault. I had never been diagnosed with sexsomnia, had no history of parasomnias, and had not undergone any kind of medical assessment.
This was not a contested defence in front of a jury - it was a unilateral decision by prosecutors, made before my case reached trial. The assumption that I had sexsomnia was used to remove intent from the accused’s actions and to close the case entirely. It left me without justice, without a voice in my own case, and with the knowledge that a medically unverified condition had been applied to me without my input.
Frustrated and determined to prove the claim unfounded, I sought out private consultations with specialist sleep clinicians. I underwent the tests that should have been ordered by the justice system - overnight studies, in-depth assessments, and medical reviews. Every specialist came to the same conclusion: there was no evidence I had sexsomnia. It was both vindicating and deeply troubling. I had been forced to carry the financial and emotional burden of disproving a condition the courts had assigned to me without a shred of medical basis.
Why It’s So Hard to Challenge
The core legal challenge lies in proving - or disproving - consciousness and intent. If sexsomnia is invoked, whether about the accused or, as in my case, the victim, it muddies the evidential waters. In criminal cases, prosecutors may feel that juries are unlikely to convict if there is even a sliver of doubt that the accused acted knowingly. In family courts, the “balance of probabilities” standard means a sexsomnia claim can tip the scales against more restrictive safeguarding measures. Compounding this is the lack of mandatory medical evidence. In many cases, the mere assertion of sexsomnia - supported by anecdotal accounts or untested personal history - is enough to influence decisions. The implications for the family court are particularly troubling. Children’s welfare can hinge on whether allegations of sexual harm are believed, minimised, or reframed through the lens of an unproven medical condition.
For victims, being told they or their abuser were “asleep” during an assault can feel like erasure - a rewriting of their lived experience to fit a narrative that removes responsibility. For me, it feels like another form of disbelief. Instead of questioning whether something happened, it questions the awareness of the person doing it - and by extension, the validity of the victim’s account. In family court, survivors often face the double burden of proving harm while defending against pseudo-medical explanations that can sway judicial decisions. This is particularly acute for non-resident parents seeking to protect their children from contact with an alleged abuser.
A System at Risk
If sexsomnia continues to be applied without rigorous verification, it risks becoming a catch-all loophole - one that can shut down criminal cases prematurely and weaken safeguarding in family law.
The stakes are high:
In criminal law, survivors may see their cases closed before reaching trial, eroding public trust in the justice system.
In family law, the misuse of sexsomnia claims can leave children in unsafe environments.
In both, a precedent is set that rare, poorly evidenced conditions can override direct testimony.
Where Change is Needed
Urgent reforms could include:
Mandatory medical testing - No sexsomnia claim should be accepted without an accredited sleep study and expert testimony.
Prosecutorial guidelines - The CPS should prohibit attributing sexsomnia to a victim without medical evidence.
Judicial training - Judges in both criminal and family courts should understand the rarity and evidential limits of sexsomnia.
Safeguarding-first approach - Family courts must err on the side of caution where sexsomnia is cited in cases involving children.
Sexsomnia is a recognised but rare medical condition. In the right circumstances, it deserves careful consideration in court. But when it is invoked without robust evidence - or, as in my case, applied to a victim without the appropriate assessments - it becomes a vehicle for injustice.
Both criminal and family courts must ensure that claims of sexsomnia are tested, verified, and never used to silence survivors or weaken protections for the vulnerable. Justice that sleeps on the facts is no justice at all.
