Disturbed behavioural adaptability as related to reproductive hormones and emotional states during the menstrual cycle

Benefits and limitations of drug studies in temperament research: biochemical responses as indicators of temperament

This paper presents a discussion of principles and problems of neurotransmitter challenge tests using examples of experiments, most of which were performed in the author's laboratory. Drugs targeting synthesis, release, receptors or reuptake of dopamine, serotonin and noradrenergic transmitter (TM) systems were used for characterizing or discriminating certain temperament or personality traits and their sub-factors. Any personality or temperament trait is characterized by multiple TM responses, thus constellations of hormone responses to drugs acting on different TM systems or on different sources of TM activity were investigated within individuals in crossover designs. The major conclusions are: (i) intra-individual patterns of hormone responses to different TM-related drugs, or to agonists and antagonists, can help to discriminate subtypes of temperament dimensions, and (ii) the latency and shape of response curves may help specify processes of biological responses related to psychological dimensions and reveal common TM sensitivities in clusters of traits. TM sensitivity, defined by hormone responses, does not always correspond to accompanying behavioural indicators, but may provide more specific information on underlying mechanisms. Additional consideration of drug doses and experimental induction of stressors may serve to identify temperament-related susceptibilities to certain drugs. Limitations of the challenge approach and recommendations for future research are discussed.This article is part of the theme issue 'Diverse perspectives on diversity: multi-disciplinary approaches to taxonomies of individual differences'.

Temperament and ovarian reproductive hormones in women: evidence from a study during the entire menstrual cycle

Personality and temperament were hypothesized to function as important factors affecting life history strategies. Recent research has demonstrated the association between temperamental traits and reproduction in humans, however, the underlying mechanisms are still poorly understood. This study presents evidence for an association between temperamental traits and woman's fecundity, as indicated by levels of ovarian steroid hormones during the menstrual cycle. On a large sample of urban, reproductive age women (n = 108) we demonstrated that activity, endurance and emotional reactivity are associated with levels of estrogen and with a pattern of change of progesterone levels. Women high in activity, high in endurance and low in emotional reactivity had up to twice as high estradiol levels and more favorable progesterone profiles as women low in activity, low in endurance and high in emotional reactivity. The temperamental traits we measured highly overlap with extraversion, neuroticism and negative emotionality that were reported to correlate with reproductive success. Our findings thus suggest a possible explanation for these relationships, linking personality and women's reproductive success through a hormonal pathway.

Serotonin und Persönlichkeit

Zusammenfassung: Es werden kurz drei wichtige Persönlichkeitstheorien vorgestellt, die die Beteiligung des serotonergen Neurotransmittersystems an der Ausprägung dispositioneller Merkmale auf der Ebene von Temperamentseigenschaften konstatieren. Der vorliegende Beitrag fasst die zentralen Befunde zusammen. Zunächst wird jedoch beschrieben, über welche Charakteristika das serotonerge Neurotransmittersystem verfügt, und welche Schwierigkeiten sich hinsichtlich der Messung von Indikatoren serotonerger Aktivität bzw. Ansprechbarkeit ergeben. Basierend auf einigen ausgewählten Befunden aus dem Bereich der biologischen Psychiatrie wird dann dargestellt, dass sich serotonerge Auffälligkeiten klinischer Populationen durchaus in den Bereich der gesunden Persönlichkeit übertragen lassen. Konkreter wird gezeigt, dass sich Personen mit erhöhter Ausprägung auf den Dimensionen Depressivität, Aggressivität und Impulsivität über eine geringe Ansprechbarkeit des serotonergen Systems im Zuge des so genannten Neurotransmitter-Challenge-Tests charakterisieren lassen. Implikationen für ein Verständnis der zugrundeliegenden Mechanismen interindividueller Differenzen und Implikationen für ggfs. veränderte diagnostische Methoden werden diskutiert.