The practice of sleep training has become a widespread method to address sleep struggles in infants. Popularised in the 1980s by Dr. Richard Ferber’s Solve Your Child’s Sleep Problems, sleep training encourages parents to allow their babies to cry for increasing periods before offering comfort, with the idea that they will eventually learn to self-soothe and sleep through the night. Over the years, this practice has gained massive traction, with proponents asserting that it creates independent, well-rested children. However, mounting evidence points to significant long-term consequences on children’s emotional and psychological development. The rise of mental health issues, including anxiety, depression, sleep disorders, and even attention-related problems such as ADHD, is alarming and coincides with the adoption of sleep training practices.
Sleep Training: Origins and Popularity
The concept of sleep training, which teaches infants to “self-soothe” through controlled crying, gained significant attention in the 1980s with the publication of Dr. Richard Ferber’s book, Solve Your Child’s Sleep Problems. Ferber’s method, known as “Ferberization,” involved letting babies cry for gradually increasing periods of time before comforting them. The premise was that babies would eventually learn to fall asleep on their own, thus creating a more predictable and less disruptive sleep schedule for both the child and the parents.
The method was framed as a solution for exhausted parents and was widely marketed as a way to address the common problem of sleep difficulties in infants. This philosophy has since evolved into a number of variations, including Dr. Harvey Karp’s The Happiest Baby on the Block, which also promotes sleep training as a means of calming and soothing babies.
Though sleep training methods promise to create well-rested children and more manageable families, they also advocate for a practice that involves ignoring babies’ cries for comfort—often at critical developmental stages. Research in developmental psychology, particularly the attachment theory pioneered by John Bowlby and Mary Ainsworth, emphasises the critical importance of emotional availability and comfort during the first years of life. According to attachment theory, when babies experience emotional distress, responsive care is essential for developing secure attachment patterns, which help children feel safe and supported in the world.
Emotional Neglect: The Deprivation of Basic Needs
Sleep training has been criticised for potentially depriving infants of one of their most fundamental emotional needs: comfort and reassurance from their caregivers. In the earliest stages of life, babies are entirely dependent on their caregivers for emotional regulation. Infants have underdeveloped self-soothing mechanisms, and their cries serve as an important signal that something is wrong—whether it’s hunger, discomfort, or a need for emotional closeness.
When caregivers ignore these cries for extended periods of time, it can have profound effects on a baby’s stress response system. Babies subjected to prolonged crying without comfort experience higher levels of cortisol, the body’s primary stress hormone. Chronic exposure to elevated cortisol levels in infancy can lead to disruptions in brain development, particularly in areas of the brain that regulate emotions, learning, and memory.
For example, studies have shown that prolonged exposure to high levels of cortisol in early life can alter the development of the hippocampus, the region of the brain involved in memory and emotional regulation. This can result in difficulties with emotional control, which may manifest as anxiety, mood disorders, and impaired cognitive function in later childhood or adulthood.
Mental Health and Neurological Disorders: A Rising Crisis
In the decades following the widespread adoption of sleep training, there has been a concerning rise in mental health disorders, including anxiety, depression, and attention-related disorders like ADHD. The correlation between these phenomena is striking, raising the possibility that early life emotional neglect could be a contributing factor.
Anxiety and Depression
According to the World Health Organisation (WHO), depression is now the leading cause of disability worldwide, affecting more than 264 million people globally. Rates of anxiety disorders have also surged, with estimates suggesting that approximately 1 in 10 people worldwide will experience an anxiety disorder at some point in their lives.
Research has shown that early attachment experiences play a significant role in the development of anxiety and depression. A study published in Development and Psychopathology found that children with insecure attachment styles, which may arise from inconsistent or neglectful parenting, are more likely to develop anxiety and depressive disorders later in life. The emotional neglect that occurs with sleep training methods, particularly those that involve prolonged crying without comfort, may contribute to insecure attachment, leading to an increased risk of mental health issues.
A 2020 study published in Frontiers in Psychology indicated that children who experience early emotional neglect are at higher risk for developing emotional regulation problems and internalising disorders, such as anxiety and depression. Since sleep training encourages parents to ignore a baby’s emotional distress, it may inadvertently contribute to these attachment difficulties.
Attention Deficit Hyperactivity Disorder (ADHD)
The prevalence of Attention-Deficit/Hyperactivity Disorder (ADHD) has risen significantly over the past several decades. According to the Centers for Disease Control and Prevention (CDC), the diagnosis of ADHD in children in the United States has more than doubled since the 1980s, from approximately 3.5% in 1980 to around 10% by 2020. This increase coincides with the rise in popularity of sleep training during the same period.
Research has shown that early life stress, including experiences of emotional neglect, can have a significant impact on the development of the prefrontal cortex, the area of the brain responsible for executive functions such as attention, impulse control, and working memory. Prolonged exposure to stress and elevated cortisol levels in infancy has been linked to impairments in these areas, potentially contributing to the development of ADHD.
In a 2017 study published in JAMA Pediatrics, researchers found that children who were exposed to early life stress—whether through trauma, neglect, or inconsistent caregiving—were more likely to exhibit symptoms of ADHD. While it’s difficult to directly attribute the rise in ADHD solely to sleep training, it is possible that practices like sleep training, which involve emotional neglect, may contribute to the neurological and behavioural patterns observed in children with ADHD.
The Global Mental Health Crisis: Sleep and Emotional Well-Being
In addition to the rise in anxiety, depression, and ADHD, sleep disorders have reached epidemic levels worldwide. According to the American Sleep Association, nearly 70 million Americans suffer from chronic sleep disorders, with insomnia being one of the most common complaints. These sleep issues are not confined to adults. Studies show that children and adolescents are also experiencing increasing rates of sleep disturbances.
The global sleep crisis seems to coincide with the rise of sleep training, particularly methods that advocate letting babies cry themselves to sleep. Research suggests that early sleep deprivation or disruptions in sleep patterns can have long-term consequences for emotional regulation and mental health. For example, a study in Pediatrics found that infants who experienced poor sleep quality were more likely to exhibit behavioural problems later in childhood.
Chronic sleep deprivation can exacerbate symptoms of anxiety and depression. Studies in both children and adults have shown that disrupted sleep patterns can lead to increased irritability, mood swings, and difficulties with concentration. Given that sleep training may disrupt natural sleep cycles and emotional regulation in infancy, it is possible that these practices contribute to the rise in sleep-related disorders and their associated mental health impacts.
Justifying Emotional Neglect: The Appeal of Sleep Training
The rise of sleep training is not solely a reflection of well-meaning parents trying to help their children sleep better. In many cases, sleep training has become a cultural norm, influenced by a broader societal emphasis on independence and self-sufficiency. Sleep training can offer a quick solution for exhausted parents who want their babies to sleep through the night, but it also provides a convenient justification for ignoring a child’s emotional needs. In a society that often pressures parents to be more self-reliant and less emotionally dependent, sleep training offers a way to “fix” a baby’s sleep problems while avoiding the discomfort of responding to their cries.
Parents may feel validated in ignoring their baby’s distress, believing they are promoting independence and better sleep habits. However, this approach overlooks the critical importance of emotional bonding and responsive caregiving during the first year of life. While sleep training may provide temporary relief for parents, its long-term consequences—both for the child’s mental health and the parent-child relationship—should not be ignored.
A Shift Toward Responsive Parenting
Given the mounting evidence of the negative effects of sleep training on children’s mental health, experts are calling for a shift toward more responsive and emotionally attuned parenting practices. Responsive parenting, which involves comforting a baby when they cry and meeting their emotional needs promptly, fosters secure attachment and promotes healthy emotional regulation.
Studies have shown that babies who experience responsive caregiving tend to develop stronger emotional resilience, improved social skills, and better mental health outcomes. In fact, research published in Pediatrics found that responsive parenting was associated with reduced rates of anxiety, depression, and behavioural problems in children. By responding to a child’s cries and providing comfort, parents help build a sense of trust and security, which is foundational for healthy emotional development.
Recommendations for Parents and Caregivers
Respond to Babies’ Emotional Needs: Rather than adhering to rigid sleep training schedules that promote ignoring a baby’s distress, parents should embrace more responsive approaches. This means picking up a baby when they cry, offering comfort and reassurance, and gradually helping them build a sense of emotional security. Research shows that when parents respond sensitively to their baby’s cries, it promotes secure attachment, healthy emotional development, and more restful sleep over time.
Promote Healthy Sleep Habits Without Emotional Neglect: While it is essential for babies to develop good sleep habits, this should not come at the expense of their emotional well-being. Strategies like creating a calming bedtime routine, ensuring a comfortable sleep environment, and establishing a consistent sleep schedule can be effective without resorting to controlled crying or leaving babies to cry themselves to sleep.
Prioritise Emotional Connection: Parents should be encouraged to build strong emotional bonds with their children by being emotionally available, physically affectionate, and responsive to their needs. Emotional connection, especially in the early years, is vital for healthy brain development and emotional regulation.
Seek Professional Guidance When Needed: If sleep difficulties persist, parents should seek guidance from paediatricians, child development specialists, or sleep consultants who prioritise a child’s emotional and psychological well-being. There are many resources available that offer gentle, attachment-based approaches to infant sleep that focus on meeting emotional needs while fostering healthy sleep patterns.
Foster Emotional Resilience Through Attachment: Secure attachment is the cornerstone of emotional resilience. Parents should remember that emotional regulation, social competence, and resilience in adulthood are all rooted in the secure attachments children form in infancy. Meeting a baby’s emotional needs, especially in their earliest years, strengthens the foundation for a healthy, well-adjusted adulthood.
Conclusions
The growing prevalence of mental health issues worldwide—ranging from anxiety and depression to sleep disorders and ADHD—cannot be ignored. This trend coincides with the rise of sleep training practices, which often involve emotional neglect, particularly in the critical early months and years of life. While sleep training methods may offer short-term solutions for tired parents, the long-term effects on a child’s emotional and mental health could be profound. By disregarding the emotional needs of babies and encouraging them to “self-soothe” at the cost of attachment, sleep training may be contributing to the escalating mental health crisis seen in children and adults today.
Studies have shown that children who grow up with secure attachment relationships—where their emotional and physical needs are met consistently—are better equipped to handle stress, are more resilient in the face of adversity, and are less likely to develop anxiety or depression later in life. By fostering emotional security in infancy, parents help lay the foundation for mental health and well-being throughout childhood and adulthood. In contrast, methods that encourage emotional neglect during infancy, such as sleep training, may undermine this security, potentially leading to lifelong emotional and psychological challenges.
Rather than adopting practices that prioritise sleep over emotional security, parents are encouraged to embrace responsive parenting methods that promote healthy attachment, emotional regulation, and long-term well-being. By responding to a child’s needs, fostering emotional connections, and creating a safe and supportive environment, parents can help ensure that their children grow up emotionally secure, resilient, and capable of navigating the challenges of adulthood with confidence.
As the mental health crisis continues to grow, society must recognise the importance of early emotional support, especially in the formative years of a child’s life. In nurturing children’s emotional needs and fostering secure attachment, we can help combat the rising tide of mental health disorders and pave the way for healthier generations to come. The evidence is clear: addressing emotional needs first, rather than simply focusing on sleep or independence, is essential for ensuring the mental and emotional well-being of children today and in the future.