My name is Karla Guerrieri, and I’m the CEO and founder of Sleep Little Angel. I grew up in Brazil and moved to London in 2011, and I am a fully trained sleep practitioner and maternity nurse, specialising in children with additional needs and childcare in the UK.

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I have been working with children for the last 23 years, in different age groups and fields.  As a nursery teacher, primary teacher, educator, special needs volunteer, nanny, maternity nurse, sleep practitioner and counsellor, I have continuously expanded my knowledge about children's wellbeing. 

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My personal experience with sleep problems started when I was five. For years I had nightmares and would also sleepwalk. I would wake in the night screaming, and my parents would comfort me until I fell asleep again. 

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My parents took me to many different doctors, but no one could help us with my sleeping issues. This affected the whole family, and everyone was exhausted. My brother began having behavioural problems at school, and I was continually tired and had difficulty concentrating. I struggled with sleep until my late teens.

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I first became interested in sleep consulting in 1997, when I trained as a primary and child development teacher to work with young children. As a teacher, I saw that when children were tired they showed concentration problems, aggressive behaviour (hyperactivity), anxiety, emotional imbalance, and struggled to communicate how they felt. These issues deeply affected their performance in school. I've been researching sleep problems since then.

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Sleep Deprivation and Mental Health: A Personal Story

In recent years, my personal experience with my father has made me reflect on the quality of sleep and its consequences. A very active man, he used to sleep for four or five hours every night, but lack of sleep never seemed to affect his routine or his mood. 
Over time, however, my father became deeply depressed. This news frightened the whole family, as he had always led a balanced and active life. Visiting a psychiatrist, the medical report indicated sleep deprivation as the main cause of his depression.

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Of course, we were all surprised. 

How can lack of sleep cause depression?

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I decided to study more about the relationship between sleep deprivation and depression. Trying to understand the reasons better, I constantly consulted psychologists and psychiatrists, and I discovered that sleep disturbances can also exacerbate the symptoms of many mental conditions, including depression, anxiety and bipolar disorder. 

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There is a complex relationship between sleep and mental health. We have all experienced a difficult day after a poor night’s sleep. Not sleeping can even become a source of stress itself. Although the links are still mysterious, research has identified lack of sleep as a cause of depression: people who experience insomnia are twice as likely to develop mental health problems.

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It took my father a year-and-a-half of psychological treatment aligned to improving his sleep quality before he could finally stop taking his sleep and depression medication. With a more rigid bedtime routine, he was able to enjoy better sleep for longer, improving his health and his ability to work.

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Sleep directly affects our physical health, mental health and well-being. Lack of sleep has immediate short-term effects, but can have devastating long-term effects too, including heart disease, type 2 diabetes and depression.
 

My personal journey with sleep has deeply shaped the way I care for others today. When I was young, I had many sleepless nights filled with nightmares and fear. My parents went through so much trying to comfort me, and those long nights showed me just how much a lack of sleep can affect an entire family. Later in life, I also watched my father face depression caused by years of poor sleep — and together, these experiences taught me how vital rest is for emotional wellbeing, balance, and connection.

My passion for supporting children began early. I started working with little ones when I was just 15 years old, and from that moment, I knew that caring for babies and families was my true calling. Over the years, I’ve seen how gentle routines and early guidance can transform not only a baby’s sleep but the peace within a home.

Today, I bring that lifelong love and understanding into my work, helping families nurture healthy sleep from the very first days of life — so both parents and children can rest, grow, and thrive together.

“From my own sleepless nights to helping families find calm — my journey is rooted in empathy, love, and the belief that every child deserves peaceful sleep.”