Ghrelin – a modulator of depression associated eating disturbances

Abstract

Aims: Appetite and eating behavior are frequently altered in psychiatric patients suffering from major depression or schizophrenia. However, little is known about the neurobiological mechanisms lying behind this phenomenon. The newly discovered gut-derived neuropeptide ghrelin simulates hunger and weight gain. Therefore, it might be involved in changes of appetite regulation during psychiatric disorders. Methods: In 22 hospitalized patients (20 depressed, 12 schizophrenic) and 24 healthy controls plasma ghrelin levels were measured and the psychometric scores on the Three Factor Eating Questionnaire (TFEQ) were assessed. Results: Neither ghrelin levels, nor TFEQ scores differed between patients suffering from depression or schizophrenia and healthy subjects. In the total group (r=0.455, corr. r²=0.138, F[4, 50]=3.007, p<0.05) and in the subgroup of depressed patients (r=0.682, corr. r²=0.427, F[1, 15]=12.163, p<0.01) TFEQ subscale 2 (disinhibition) was predicted by BMI corrected ghrelin levels, while age, gender, smoking, and medication did not show any influence. Conclusions: Ghrelin seems to be involved in appetite regulating pathways during psychiatric disorders like major depression or schizophrenia. However, its influence is not likely to be displayed as a difference between diagnostic groups. Rather, ghrelin is associated with a trait factor of eating behavior in depressed patients meaning susceptibility to eating problems.