A new study has for the first time in humans linked levels of leptin, a hormone produced by fat cells, with symptoms of depression and anxiety independent of weight. The study, published in the journal Clinical Endocrinology and led by Dr Elizabeth Lawson from Harvard Medical School and Massachusetts General Hospital, USA, suggests that leptin levels may be related to depressive and anxiety symptoms in women regardless of weight or body fat.
Lawson and her team studied 64 women in four groups: 15 with anorexia nervosa, 20 normal weight and healthy, 17 overweight or obese, and 12 normal weight with hypothalamic amenorrhoea (women with this condition do not menstruate and have low leptin levels, but unlike anorexic women their fat levels do not differ from healthy
They measured fasting blood leptin levels, weight, and total body fat, and administered tests for depression and anxiety symptoms, and levels of experienced stress (HAM-D, HAM-A and Perceived Stress Scale respectively; higher scores signify increased
For the first time in humans levels of the hormone leptin (known to be one of the group of hormones involved in appetite regulation) and symptoms of depression and anxiety are negatively correlated, independently of fat mass or body weight. This independence strengthens the link because it controls for confounding relationships between fat mass and leptin. Further studies with larger sample sizes are now needed to determine exactly how leptin and depressive and anxiety symptoms
Lead researcher Dr Elizabeth Lawson from Massachusetts General Hospital and Harvard Medical School, USA
“Our findings place leptin on a growing list of hormones that are correlated with psychiatric symptoms. Whether leptin influences depression or vice versa, and whether the relationship is direct or mediated by a third as yet unknown factor needs to be
“Further studies administering leptin to patients will be important in determining whether this hormone has a potential role in the treatment of depression and/or anxiety.”
Full bibliographic information
Leptin Levels Are Associated With Decreased Depressive Symptoms in Women Across the Weight Spectrum, Independent of Body Fat
Elizabeth A. Lawson et al.