Study Links Low Leptin Levels With Depression Regardless Of Weight

A new study has investigated the relationship between levels of appetite regulating hormones and symptoms of depression, stress, and anxiety in women, regardless of their weight.

64 women were studied. Of these women, 15 were diagnosed with anorexia, 12 were of normal weight with hypothalamic amenorrhea (lack of menstrual periods due to a low functioning hypothalamus), 17 were overweight or obese, and 20 were of normal weight and in good health.

Depression and anxiety frequently occur in women with anorexia (an illness linked to low weight, low levels of leptin, and high levels of ghrelin), as well as women of normal weight with hypothalamic amenorrhea. More recently, obesity has been linked to an increased risk of depression and anxiety. The researchers therefore wished to investigate the relationship between depression and anxiety among a cross section of women, and their serum levels of leptin and ghrelin.

The researchers measured levels of the hormones leptin (which inhibits appetite) and ghrelin (which functions as a counterpart to leptin by increasing appetite). Bloodwork was performed on participants after fasting, and several tests were administered to measure depression, anxiety, and perceived stress. The results were controlled for body fat or weight.

The experimental data clearly indicate a link between low leptin levels and depression, regardless of the women’s weight. Furthermore, participants with increased depression ratings were found to have lower levels of leptin. These results correspond with studies performed on animals in which increased levels of leptin have been attributed to antidepressant and anti-anxiety effects.

The researchers admit that more investigation is necessary, including administering leptin to humans as a potential treatment for depression and/or anxiety. The article is available online in unedited form.

Source: Wiley Online Library