Serotonin 5-HT(2A) receptor gene polymorphism, 5-HT(2A) receptor function and personality traits in healthy subjects: a negative study.

Background: Central serotonin-2A (5-HT(2A)) receptor dysfunction is regarded as an important factor in the etiology of affective disorders. The relations between some personality traits and the vulnerability of affective disorders are also implicated. Moreover, there are several reports which describe the association between 5-HT(2A) receptor gene polymorphisms and mental disorders. We therefore examined the relationship between personality traits, the 5-HT(2A) receptor function, and 5-HT(2A) receptor gene polymorphisms.

Methods: 5-HT-induced intraplatelet calcium (Ca) mobilization, 5-HT(2A) receptor gene polymorphisms (A-1438G, T102C, T516C, C1340T, C1354T), and Temperament and Character Inventory (TCI) scores were examined in 133 healthy subjects.

Results: Neither 5-HT-induced Ca mobilization nor 5-HT(2A) receptor gene polymorphisms (A-1438G, T102C) appear to be associated with seven personality dimensions including Harm Avoidance. There was no significant difference in the Ca response among the subjects with -1438A/A, A/G and G/G genotypes. Since the appearance of the other types of the 5-HT(2A) receptor gene polymorphisms (T516C, C1340T and C1354T) was quite rare in our sample, we were unable to examine the relationship between these polymorphisms, and the TCI score or the Ca response.

Limitations: Our failure to find a significant association may reflect the false negative results due to the small sample size and low statistical power. Further studies in depressed patients may clarify the complicated relationship between personality traits and the vulnerability of affective disorders.

Conclusions: Personality traits detected by TCI may not be directly related to the 5-HT(2A) receptor function or 5-HT(2A) receptor gene polymorphism which may be involved in the vulnerability of affective disorders.