If there is one thing I could change about how we support young people's mental health, it would be this: take their sleep seriously.
Sleep is not a nice-to-have. It is the foundation on which every other aspect of mental health sits. Mood regulation, emotional resilience, cognitive function, memory consolidation, physical health, immune function, and the capacity to manage stress - all of these depend on adequate, quality sleep. When sleep is compromised, everything built on top of it becomes unstable.
And in adolescents, sleep is being compromised on a massive scale.
Here is the neuroscience. During puberty, the circadian rhythm - the body's internal clock - shifts forward by one to two hours. This is not a lifestyle choice or a character flaw. It is a biological change driven by hormonal shifts. A teenager whose body is telling them to fall asleep at 11pm and wake at 8am is not being lazy - they are responding to a genuine physiological shift.
The problem is that the school system does not accommodate this. Most secondary schools start at 8:30am or earlier, which means an alarm at 7am or earlier. If a teenager's biology is not allowing them to fall asleep until 11pm, they are getting eight hours at best - and many are getting significantly less. The result is chronic sleep deprivation across the school week, with attempted catch-up at weekends that disrupts the circadian rhythm further.
Now layer on top of this the factors that actively interfere with sleep. Blue light from screens suppresses melatonin production and further delays sleep onset. Social media creates stimulation and emotional activation at exactly the time the brain needs to be winding down. Caffeine (in the form of energy drinks, which many teenagers consume regularly) has a half-life of five to six hours, meaning a caffeine hit at 4pm is still active at 10pm. Academic pressure creates anxiety that activates the stress response at bedtime. And for neurodivergent teenagers, additional factors come into play - ADHD brains often have difficulty with the 'switching off' process that sleep onset requires, and sensory sensitivities can make the sleep environment itself problematic.
The mental health consequences of chronic sleep deprivation in adolescents are significant and well-documented. Mood dysregulation: sleep-deprived teenagers are more emotionally reactive, more irritable, and less able to regulate their emotional responses. If your teenager seems to overreact to everything, poor sleep may be the biggest contributing factor. Anxiety: sleep deprivation increases activity in the amygdala (the brain's threat detection centre) while reducing the capacity of the prefrontal cortex to regulate it. In plain terms, an under-slept teenager is neurologically primed for anxiety. Depression: the relationship between sleep and depression is bidirectional. Poor sleep increases the risk of depression, and depression disrupts sleep. Intervening on sleep often produces significant improvement in depressive symptoms. Cognitive function: attention, concentration, memory, and decision-making are all impaired by sleep deprivation. A teenager who is struggling academically may be struggling primarily because they are not sleeping enough.
So what can families do? Start with the sleep environment. The bedroom needs to be dark (blackout curtains or an eye mask), cool (around 16-18 degrees Celsius is optimal), and quiet. These are the basic conditions the brain needs for quality sleep.
Address the phone. I said this last week and I will say it again - charging phones outside the bedroom overnight is one of the most impactful changes a family can make. It removes the blue light, the social media stimulation, and the temptation to check notifications in the night. If your teenager uses their phone as an alarm clock, buy them a clock. It is a small investment with an outsized return.
Create a wind-down routine. The brain needs a transition period between activity and sleep. A consistent routine in the hour before bed - dim lighting, no screens, a warm shower, reading, gentle music - signals to the circadian system that sleep is approaching. This is not just for small children. Adolescent brains benefit from the same cues.
Be cautious about caffeine. Energy drinks are marketed to young people and many teenagers consume them without understanding the impact on sleep. A conversation about caffeine timing (nothing after midday if sleep is a problem) can make a significant difference.
For neurodivergent teenagers, additional strategies may be needed. Weighted blankets can help with the sensory regulation that supports sleep onset. White noise or brown noise can mask environmental sounds that disrupt sleep. A highly structured bedtime routine provides the predictability that many neurodivergent brains need to transition to sleep. And for teenagers with ADHD, the timing of medication may need to be discussed with their prescriber, as some ADHD medications can interfere with sleep.
If sleep problems are persistent and significant - if your teenager is regularly unable to fall asleep for more than an hour, waking frequently, or so tired during the day that they cannot function - it is worth seeking professional support. Your GP can rule out medical causes and make appropriate referrals. In therapy, we can work on the anxiety, worry, and emotional patterns that often maintain sleep difficulties.
Finally, a note on language. When we call teenagers 'lazy' for sleeping late, we are pathologising a biological reality. When we praise early risers as disciplined and label late sleepers as unmotivated, we are applying moral judgments to circadian biology. Teenagers are not lazy. Their brains are wired for different sleep patterns. Our system does not accommodate that - and that is a systems problem, not a character problem.