Thyroid and depression: what should you know?

An underactive thyroid may be associated with low mood, tiredness, slowed thinking, feeling cold and changes in sleep. Depression can also involve low mood, loss of interest, fatigue, difficulty concentrating and sleep changes. An overactive thyroid may bring anxiety, irritability, restlessness, palpitations and poor sleep, which can feel emotionally overwhelming. These patterns overlap, but one does not prove the other. A thyroid blood test can help assess thyroid function, while questions about mood, interest, daily functioning and safety help assess depression.

Symptoms such as daytime sleepiness, difficulty sleeping, fatigue, feeling anxious and irritability can have several explanations. Keeping a brief record of when symptoms began, how they vary and whether they affect work or relationships can make the consultation more useful.

Arrange a GP consultation if symptoms persist, interfere with daily life or return after a period of improvement. Bring a list of medicines, supplements and previous thyroid results if available. Do not start, stop or change thyroid medicine or an antidepressant without medical advice. Treatment depends on the findings and may involve thyroid care, support for depression, or attention to both. Regular meals, a steady sleep routine, gentle activity and contact with trusted people may support wellbeing while you seek care.

Seek urgent help if you feel unable to stay safe, have thoughts of harming yourself, become severely confused or develop chest pain, fainting or severe breathlessness. Contact a clinician promptly for rapidly worsening mood, marked agitation, new severe palpitations or a major change in sleep and energy. Emergency services are appropriate when immediate safety is at risk.

Could thyroid function be contributing to my symptoms? Which blood tests are appropriate? How will you assess depression separately? Could any medicine or supplement be affecting my mood or thyroid? What changes should prompt an earlier review?