For some people, the worst part of the day comes in the first few minutes after the alarm. The mood is heavy before anything has gone wrong, and it can lift by lunchtime. It is common enough that many people search online for why they feel sad when they wake up.
Part of the answer lies in the body clock. A 2008 review published in Dialogues in Clinical Neuroscience by a researcher at the Centre for Chronobiology at the Psychiatric University Clinics in Basel explains that nearly everything the body does rises and falls across 24 hours.
Hormones such as cortisol and melatonin follow daily rhythms, as do body temperature and heart rate. Laboratory studies suggest that mood follows a similar pattern, shaped by the circadian clock working together with the pressure to sleep that builds up while we are awake.
Doctors call these daily swings diurnal variation. Feeling worse in the morning and better as the day goes on has long been seen as a classic feature of depression, particularly the more severe form known as melancholic depression.
The review found the picture is less tidy than textbooks suggest. Morning lows, an afternoon slump, and evening worsening can all appear in the same person during a single episode of depression. Healthy people can also show daily mood swings, so a gloomy start to the day is not proof of illness on its own.
Sleep timing matters too. Many people with depression, especially those with bipolar disorder, have a late body clock, meaning they naturally fall asleep and wake later. Even small shifts in when and how long someone sleeps can change mood, and the review notes that keeping sleep in step with the body clock, for example with light therapy, can help stabilise mood.
Practical steps follow from this. Going to bed and waking at the same time each day, getting outside in daylight, and avoiding phones right before bed are all habits the NHS suggests for low mood linked to the seasons.
The NHS lists continuous low mood, feeling hopeless, losing interest in things, and lack of energy among the signs of depression. Disturbed sleep is another, including finding it hard to fall asleep or waking up very early in the morning.
The key question is how long it lasts. The NHS advises seeing a GP if you have symptoms of depression for most of the day, every day, for more than two weeks. A low mood that clears after a few days is common and often improves on its own.
Darker mornings in autumn and winter can make waking harder for many people, and for some this forms part of seasonal affective disorder. Psychreg has more tips for managing seasonal depression.
Anyone who wakes with thoughts of suicide or self-harm should seek urgent help through NHS 111, their GP, or emergency services rather than waiting for the feeling to pass. Samaritans is free on 116 123, day or night.
