Bone Density and Major Depression in Adolescents

For over a decade, Dr. David Herzog, Emeritus Professor of Psychiatry at Harvard Medical School, has collaborated with the Neuroendocrine Unit at Massachusetts General Hospital (MGH) to learn more about the impact of anorexia nervosa on bone formation during adolescence.  Now the team is also examining bone mass in teenagers diagnosed with major depressive disorder.

Major depression is common in adolescents.  Among school-aged children, the prevalence is 2%-3% and increases to 4% to 8% among teenagers.  Adolescence is also a key period of bone growth.  Over 90% of a person’s bone mass has developed by age 18.

Dr. Herzog and his team of scientists in the MGH Neuroendocrine Unit recruited 65 adolescents between the ages of 12 and 18.  32 participants were boys (16 with major depressive disorder and 16 healthy controls) and 33 were girls (17 with major depressive disorder and 16 controls). Dual energy x-ray absorptiometry (DXA) was used to measure participants’ bone density of the lumbar spine and hip, and blood tests were drawn to determine levels of estradiol (the major form of estrogen), testosterone, Vitamin D, and bone turnover markers (biochemical markers of either bone formation or bone resorption).

The study found that boys with major depressive disorder had a significantly lower bone mineral density compared with healthy controls after adjusting for body mass index. This significant finding was maintained after also adjusting for lean mass and bone age.  In contrast, bone mineral density in girls with major depression did not differ from controls.  It is important for clinicians caring for adolescents, especially boys with depression to be of aware of these findings and the potential for increased risk of fracture. This was the first time the relationship between bone density and depression in adolescent boys has been studied, and further research will shed more light on the topic.