Why does depression cause fatigue?

Fatigue is a very common presentation of Depression. It can feel like physical heaviness, slowed thinking, low stamina, or needing far more effort to start a task. Sleeping longer does not always restore energy, particularly when sleep is broken or unrefreshing. Depression can also reduce interest in movement, meals, social contact, and routines that normally support energy. Fatigue alone does not identify its cause: infections, anaemia, thyroid problems, pain, sleep disorders, medicines, and other concerns can contribute. A clinician can consider the full pattern rather than treating fatigue as a character flaw.

Tell someone you trust how fatigue is affecting your day. Break essential tasks into small actions, such as washing, eating something simple, or stepping outside for daylight. Plan the most demanding task for the time of day when you have the most energy, and allow pauses without judging yourself. Regular meals, fluids, a steady wake time, and gentle movement can support recovery when they are manageable. Keep a note of fatigue, sleep, mood, appetite, and medicines to take to an appointment. Do not stop an antidepressant or other prescribed medicine suddenly.

Book an appointment if fatigue persists, limits self-care or work, or occurs with low mood and loss of interest. Seek assessment sooner if it begins after a new medicine, comes with marked breathlessness, chest pain, fainting, fever, or unexplained physical changes. Get urgent help immediately for thoughts of self-harm, a plan to harm yourself, or feeling unable to remain safe; contact emergency services or go to the nearest emergency department.

Ask whether your fatigue could have more than one cause, whether any medicines may be adding to it, and which checks are appropriate. You can also ask how treatment for depression may affect energy, sleep, and concentration over time.