A reader wants to know if depression could be caused by undetected thyroid or hormonal changes. The short answer is yes. Hypothyroidism (an underactive thyroid gland), hyperthyroidism (an overactive thyroid gland), and adrenal insufficiency (a dysfunctional adrenal gland) are hormone disorders that can cause symptoms of depression. These illnesses can be detected by simple tests performed by your child's pediatrician.
Other medical conditions that may be associated with depressive symptoms include metabolic illness, anemia, seizure disorder, acquired immunodeficiency syndrome, Addison's disease, post-concussion, tuberculosis, diabetes, brain tumor, and chronic fatigue syndrome. Medications that can cause depression include antihypertensives, barbituates, corticosteroids, oral contraceptives, and albuterol. Green-Hernandez, C., Singleton, J. K., & Aronzon, D.Z. (2001). Primary care pediatrics. Philadephia: Lippincott, Williams & Wilkins, pg 314.
Hormonal changes at puberty have been linked to an increase in depression in adolescents as compared to children. There is little difference in the rates of depression between boys and girls prior to puberty, but among teenagers, twice as many girls as boys become depressed. It is unclear why there is such a significant gender difference. Many research studies show inconsistent results for hormone levels, early or late onset of puberty, psychosocial differences, and body image issues as possible causes. One explanation could be that hormonal changes only affect girls with a genetic predisposition for depression. Gotlib, I. H. & Hammen, C. L. (Eds.),2008. Handbook of depression (2nd ed.). New York: Guilford Press, pgs 388-389.