The Metabolic Syndrome (MetS) is defined as a cluster of cardiometabolic risk factors affecting the same subject, when three out of the following five criteria are present: abdominal obesity, hypertriglyceridemia, low HDL cholesterol, hypertension, impaired glucose tolerance (or diagnosis of Type 2 Diabetes). Recent studies on the association between the MetS, depression and anxiety have reported conflicting findings; yet, clinically they are very frequently present in the same patient.

To review findings supporting the opportunity of considering the presence of depressive/anxiety symtoms as the “sixth criterion” of the Metabolic Syndrome.

Systematic review. A Medline search of the literature conducted on September 12th, 2012 (key words: metabolic syndrome, anxiety, depression) provided 148 references. A further temporal-limit of the search, taking into account only papers published in the last five years, provided 90 references. Finally, 16 studies were retained eligible for the present study.

Of 16 papers, 3 reported absolutely no association between MetS, depression and anxiety; 5 reported a significant correlation. As far as depression is concerned, 5 papers reported a correlation with MetS, 1 reported no correlation between MetS and the Major Depressive Disorder. As far as anxiety is concerned, 4 papers reported a significant correlation with MetS, 2 reported no correlation. The most reproducible finding was the correlation between anxious/depressive symptoms and the MetS (especially large waist circumference), when affecting women.

The presence of depression and/or anxiety could be considered the sixth criterion to diagnose the MetS in females with large waist circumference.