AFFECTIVE TEMPERAMENT AND POLIMORPHISMS IN GENES CODING ELEMENTS OF DOPAMINERGIC PATHWAYS IN OBESITY SUBJECTS

Background Temperament is a group of inherited personality traits that emerge in the early stages of human life. Such temperament is the basis of personality formation. The Hagop Akiskal, based on the theorems of Kraepelin and Kretschmer, established the existence of five types of affective temperament: depressive, hyperthymic, cyclothymic, irritable and anxious. It is now accepted that temperament is a constant, hereditary core of the personality that is virtually unchanged throughout life. Methods 506 patients diagnosed with obesity were included to the study after exclusion of significant psychiatric illnesses. Patients were subjected to clinical, psychological and genetic evaluation. The psychological assessment consisted in determining the severity of depressive symptoms (using the Beck Depression Inventory and Hamilton's Depression Scale) and the assessment of the affective temperament profile using TEMPS-A. Genetic evaluation consisted in the determination of polymorphisms DAT1 VNTR (SLC6A3) and cathelol-O-methyltransferase COMT (Val158Met). Results The results indicated an association between COMT and DAT1 alleles with depressive symptoms, BMI and as well as temperamental dimensions. Val homozygotes in COMT analysis scored less in both depression scales also they were less depressive, cyclothymic, irritable and anxious. Subjects homozygous for the nine-repeat allele scored higher in BDI (p=0.02) and HDRS (p=0.00001), suggesting higher intensity of depression, in both sexes. This allele was also associated with the highest Body Mass Index (BMI, p=0.001). Discussion Polymorphisms in the DAT1 and COMT genes are associated with greater intensity of depressive symptoms as well as higher BMI and affective temperament dimensions in obese individuals.