Self-rated aggression. Psychobiological aspects and gender issues in medical-psychiatric practice

Abstract

Background. The complexities of human aggression are of vital research interest in numerous scientific disciplines. In medical research, aggression is generally studied by means of self- or observer-rated inventories, clinical observations, or neurobiological research. Objectives. To test the hypothesis that replicable, gender-specific patterns might be involved in relationships between aggression, psychiatric conditions, and neurobiology. In particular, the study was designed to:· develop and standardize a self-rating aggression instrument for clinical and research purposes in a Swedish population,· study self-rated aggression and its components in a selection of psychiatric and medical disorders (persistent depressive disorder, PDD, first-episode depression, FED, and fibromyalgia syndrome, FMS) in relation to: 1) each other, 2) their neurobiological features, and 3) gender, · compare self-rated aggression in the patient groups with self-rated aggression in the general Swedish population.Methods. A self-rating instrument, the Aggression Questionnaire - Revised Swedish Version (AQ-RSV) was standardized on the basis of data from 781 individuals, randomly selected from the Swedish population register (Paper I). In the study described in Paper II, we used all demographic and aggression data from 497 recipients, whereas data from the 267 female responders alone were used in the studies described in Papers III and IV. In Papers II and III, we studied the aggression factors Total, Physical, and Verbal Aggression, Anger, and Hostility in relation to neurobiological aggression markers (the monoamine metabolites 5-hydroxy-indoleacetic acid (5-HIAA) and 3-methoxy-4-hydroxyphenyl glycol (MHPG), serum testosterone, and platelet monoamine oxidase (MAO) activity). Results and Conclusions. In brief, the main findings of the project were: 1. In the general population, self-rated aggression usually decreases with age. The one exception is Anger, which in 20-year-olds is lower in men than in women. In 40-year-olds, however, male and female Anger had reached similar levels.2. The AQ-RSV scores were higher in each patient group studied than in the general Swedish population.3. In the general population, men are usually more aggressive than women as assessed by AQ-RSV, but the ratio between male and female self-rated aggression was inverted among patients with PDD. 4. In women with FMS, increased serum testosterone in combination with low platelet MAO activity predicted increased AQ-RSV scores. 5. Positive relations between 5-HIAA, MHPG, and AQ-RSV revealed significant relationships between self-rated aggression monoaminergic turnover. 6. Gender distinctly modified the linkage between aggressive symptoms and central monoaminergic turnover in PDD.