Temperament, character and serotonin activity in the human brain: a positron emission tomography study based on a general population cohort

Abstract

Tuominen, L.; Salo, J.; Hirvonen, J.; Någren, K.; Laine, P.; Melartin, T.; Isometsä, E.; Viikari, J.; Cloninger, C. R.; Raitakari, O.; Hietala, J.; and Keltikangas-Järvinen, L., ,"Temperament, character and serotonin activity in the human brain: A positron emission tomography study based on a general population cohort." Psychological Medicine. 43,4. 881-894. (2012 Background. The psychobiological model of personality by Cloninger and colleagues originally hypothesized that interindividual variability in the temperament dimension ' harm avoidance ' (HA) is explained by differences in the activity of the brain serotonin system. We assessed brain serotonin transporter (5-HTT) density in vivo with positron emission tomography (PET) in healthy individuals with high or low HA scores using an ' oversampling ' study design.Method. Subjects consistently in either upper or lower quartiles for the HA trait were selected from a populationbased cohort in Finland (n=2075) with pre-existing Temperament and Character Inventory (TCI) scores. A total of 22 subjects free of psychiatric and somatic disorders were included in the matched high-and low-HA groups. The main outcome measure was regional 5-HTT binding potential (BP ND ) in high-and low-HA groups estimated with PET and [ 11 C]N,N-dimethyl-2-(2-amino-4-methylphenylthio)benzylamine ([ 11 C]MADAM). In secondary analyses, 5-HTT BP ND was correlated with other TCI dimensions.Results. 5-HTT BP ND did not differ between high-and low-HA groups in the midbrain or any other brain region. This result remained the same even after adjusting for other relevant TCI dimensions. Higher 5-HTT BP ND in the raphe nucleus predicted higher scores in ' self-directedness '.Conclusions. This study does not support an association between the temperament dimension HA and serotonin transporter density in healthy subjects. However, we found a link between high serotonin transporter density and high ' self-directedness ' (ability to adapt and control one's behaviour to fit situations in accord with chosen goals and values). We suggest that biological factors are more important in explaining variability in character than previously thought.

Changes in the Temperament and Character Inventory dimensions after paroxetine treatment in patients with major depressive disorder

“…In the present study, only the SD scores of the non-responders significantly changed based on repeated-measures two-way ANOVAs, but in the responders and early responders, the mean HA score decreased, and the mean SD score increased after the treatment. Cloninger (1987) claimed that the HA dimension correlated to serotonin, but Tuominen et al (2013) reported that there was no association between the HA dimension and the serotonin transporter density based on a positron emission tomography study; there were no significant differences in the HA dimension even though the participants took SSRIs, which influence the serotonin pathway. As such, the results of the present study support the results of Tuominen et al We could possibly follow the response to treatment for patients with MDD by investigating the SD score.…”

Trait Openness and serotonin 2A receptors in healthy volunteers: A positron emission tomography study

“…In line with the findings from the current study, another study found no significant association between 5‐HT 1A R and trait Self‐transcendence (Karlsson, Hirvonen, Salminen, & Hietala, ), and two other studies reported nonsignificant associations between trait Openness and 5‐HT 4 R (Stenbaek et al, ) and 5‐HT 1A R (Tauscher et al, ), respectively. Some studies reported significant associations between 5‐HT receptor or 5‐HTT binding and other personality traits from NEO PI‐R and TCI, but none in relation to trait Openness or Self‐transcendence (Tauscher et al, ; Tuominen et al, ; Tuominen et al, ). Conversely, other PET studies investigated associations between 5‐HT receptor or 5‐HTT binding and personality traits from NEO PI‐R and TCI, but did not report associations with trait Openness or Self‐transcendence (Frokjaer et al, ; Frokjaer et al, ; Gerretsen et al, ; Moresco et al, ; Reimold et al, ; Soloff, Chiappetta, Mason, Becker, & Price, ; Soloff, Price, Mason, Becker, & Meltzer, ; Takano et al, ), possibly reflecting null findings.…”

Relationship of self‐transcendence traits with in vivo dopamine D2/3 receptor availability and functional connectivity: An [18F]fallypride PET and fMRI study

“…A series of molecular positron emission tomography (PET) imaging studies examined the relationship between in vivo serotonergic markers and self-transcendence in groups of healthy individuals, but found inconclusive results (Borg, Andrée, Soderstrom, & Farde, 2003;Karlsson, Hirvonen, Salminen, & Hietala, 2011;Kim et al, 2015;Tuominen et al, 2013). However, the relationship between in vivo dopaminergic neurotransmission and the self-transcendence trait is hitherto undocumented.…”