Teens with low iron: around twice the odds of an anxiety disorder

In a study of nearly 15,000 young people, adolescents with iron deficiency anemia had roughly twice the odds of an anxiety disorder, and about the same for depression. It takes a blood test that most of them never get.

Anxiety in teenagers is usually treated as purely psychological. For some it is not the whole picture, and the thing that gets missed is cheap to rule out.

The finding

A nationwide study compared 2,957 children and adolescents diagnosed with iron deficiency anemia against matched controls, four controls for every case (Chen 2013, BMC Psychiatry). Those with the deficiency had 2.17 times the odds of an anxiety disorder (95% CI 1.49 to 3.16), and 2.34 times the odds of unipolar depression (1.58 to 3.46). ADHD and developmental delay also came out raised.

That is an association, not proof of cause. It cannot tell you which came first, and a database of diagnoses is a blunt instrument. It is still a strong enough signal to justify a blood test.

Why iron matters for mood

Iron is a cofactor for the enzymes that build dopamine and serotonin, and it carries oxygen to the brain. When it runs low, chemistry and energy supply both suffer, which shows up as anxiety, irritability, fatigue and poor focus.

The step that gets skipped

Ask for ferritin by name. A standard full blood count reads hemoglobin, and hemoglobin is the last thing to fall, so iron stores can be empty while the result still looks normal.

If anxiety comes with tiredness, pallor or heavy periods, that is worth saying out loud at the appointment.

General information only. Testing and treatment should go through a clinician.

This article is for general information and is not a substitute for professional care. If you are in crisis or thinking about harming yourself, please contact your local emergency services or a crisis line. See crisis lines.