Original article
Personality traits measured with TEMPS-A and O-LIFE and polymorphism of BDNF, COMT and serotonin transporter genes in bipolar affective illness

Aim of the study: This study assesses an association between functional polymorphisms of the brain-derived neurotrophic factor (BDNF) gene, catechol-O-methyltransferase (COMT) gene and serotonin transporter gene and personality dimensions measured by the Temperament Scale of Memphis, Pisa, Paris and San Diego – Autoquestionnaire (TEMPS-A) and the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE) in patients with bipolar affective illness.

Material and methods: The study was performed on 70 patients with bipolar affective illness (21 men, 49 women) aged 59 ±12 years, from the outpatient clinic, Department of Adult Psychiatry, Poznan University of Medical Sciences. The TEMPS-A was applied, measuring depressive, hyperthymic, cyclothymic, irritable and anxious temperament as well as the O-LIFE, measuring schizotypy dimensions: unusual experiences, cognitive disorganization, introversion and anhedonia and impulsive nonconformity. Genotyping of Val66Met polymorphism of the BDNF gene, Val108Met polymorphism of the COMT gene and 5-HTLPR s/l polymorphism of the serotonin transporter gene was performed.

Results: Carriers of the Met allele of Val66Met BDNF gene polymorphism showed significantly higher irritability dimension on TEMPS-A. Among carriers of the Met allele of Val108Met COMT gene polymorphism, significantly higher cognitive disorganization and introvertive anhedonia on O-LIFE were observed. Finally, patients with s/s genotype of 5-HTLPR polymorphism had a higher cyclothymia dimension at the level of a statistical trend (p = 0.06).

Conclusions: The association between BDNF gene polymorphism and irritability in the TEMPS-A has not been previously reported. A connection between the COMT gene and features of schizotypy as well as between the serotonin transporter gene and cyclothymia is discussed in the context of results of other researchers.