People can and do eat in their sleep, an involuntary behavior more complex than simple midnight snacking. This phenomenon involves getting out of bed, engaging in complex motor activities like cooking or retrieving food, and consuming it without conscious awareness. Episodes are often discovered by finding wrappers, dirty dishes, or food remnants, leaving the individual confused about their nighttime actions. This strange behavior is recognized as a specific medical condition that requires professional diagnosis and targeted treatment.
Sleep-Related Eating Disorder Defined
Sleep-Related Eating Disorder (SRED) is classified as a type of parasomnia, referring to abnormal behaviors that occur while a person is sleeping. Individuals with SRED experience recurrent episodes of involuntary eating and drinking during partial arousals from sleep. These episodes typically involve consuming large amounts of food in a binge-like fashion, often within the first few hours after falling asleep.
A defining characteristic of SRED is the complete or partial amnesia regarding the event, meaning the person has little to no memory of the activity upon waking. The types of food consumed can be highly unusual, ranging from raw ingredients to non-food items like soap or cigarettes. This introduces significant risks of injury, poisoning, or choking.
The Mechanism of Unconscious Arousal
The underlying cause of SRED is the brain’s failure to fully transition from deep sleep to full wakefulness, a state known as incomplete arousal. SRED is categorized as a non-Rapid Eye Movement (NREM) parasomnia, similar to sleepwalking or sleep terrors. These episodes typically originate from the deepest stages of NREM sleep, generally within the first third of the night.
During an incomplete arousal, parts of the brain responsible for movement and basic instinctual drives, like eating, become partially active. Simultaneously, the prefrontal cortex, which controls conscious judgment, self-awareness, and memory formation, remains deeply asleep. This dissociation allows complex motor functions without conscious memory or rational thought. The person is physically capable of walking and consuming food, yet they are functionally unconscious.
Primary Causes and Risk Factors
Several factors can increase an individual’s susceptibility to SRED episodes, often acting in combination to destabilize the sleep-wake cycle. The use of certain medications is a major trigger, particularly non-benzodiazepine sedative-hypnotics, such as zolpidem, commonly prescribed for insomnia. These drugs can deepen NREM sleep and promote the incomplete arousals that lead to complex sleep behaviors.
Co-existing sleep disorders that fragment sleep are also strongly associated with SRED. Conditions causing frequent awakenings, such as Obstructive Sleep Apnea (OSA) or Restless Legs Syndrome (RLS), repeatedly interrupt the sleep cycle. These interruptions push the brain into the vulnerable state of partial arousal from which SRED episodes emerge. Treating the underlying sleep disorder often reduces or eliminates the SRED behavior.
Psychological and environmental factors can further predispose a person to nocturnal eating episodes. Chronic stress, anxiety, or attempts at restrictive daytime dieting have been observed to trigger SRED. The cessation of substances like alcohol or nicotine, or a family history of other NREM parasomnias, can also increase risk.
Diagnosis and Treatment Approaches
The initial step in addressing SRED involves a detailed medical and sleep history, often confirmed by a bed partner who witnesses the nighttime behavior. While diagnosis can sometimes be made based on reported symptoms, a sleep study, or polysomnography, may be ordered to rule out other co-occurring sleep disorders. Polysomnography monitors brain waves, oxygen levels, heart rate, and leg movements to identify conditions that fragment sleep, such as Obstructive Sleep Apnea or Restless Legs Syndrome.
Treatment strategies focus on both behavioral modifications and medical interventions to stabilize sleep architecture. Implementing strict sleep hygiene practices, such as maintaining a consistent sleep schedule and ensuring the bedroom is dark and quiet, is a foundational step. Managing stress through relaxation techniques or therapy can also reduce the frequency of partial arousals.
From a medical standpoint, treatment often begins with discontinuing or adjusting any implicated sedative-hypnotic medications, such as zolpidem, under medical supervision. If an underlying sleep disorder like OSA or RLS is identified, treating it with a CPAP machine or specific medications, respectively, is necessary. For refractory cases, certain medications, including the anticonvulsant topiramate or specific dopamine agonists, may be used to suppress the abnormal nighttime behaviors.