Alfonso Troisi

A modest proposal: displacement activities as an indicator of emotions in primates

Abstract Displacement activities are behaviour patterns (mostly body care activities) characterized by their apparent irrelevance to the situation in which they appear. Scratching, autogrooming, yawning and body shaking are among the most commonly reported displacement activities in non-human primates. A review of the primate literature indicates that displacement activities tend to occur in situations of psychosocial stress and that their frequency of occurrence is affected by anxiogenic and anxiolytic drugs. In the light of this evidence, it is suggested that displacement activities can be used as indicators of emotional states arising in a variety of primate social interactions. Methodological problems associated with such a use are discussed. The hypothesis that displacement activities may also have a communicative function in non-human primates is not supported adequately by available data.

Displacement Activities as a Behavioral Measure of Stress in Nonhuman Primates and Human Subjects

Traditionally, research on human stress has relied mostly on physiological and psychological measures with a relatively minor emphasis on the behavioral aspects of the phenomenon. Such an approach makes it difficult to develop valid animal models of the human stress syndrome. A promising approach to the study of the behavioral correlates of stress is to analyze those behavior patterns that ethologists have named displacement activities and that, in primates, consist mostly of self-directed behaviors. In both nonhuman primates and human subjects, displacement behavior appears in situations characterized by social tension and is likely to reflect increased autonomic arousal. Pharmacological studies of nonhuman primates have shown that the frequency of occurrence of displacement behavior is increased by anxiogenic compounds and decreased by anxiolytic drugs. Ethological studies of healthy persons and psychiatric patients during interviews have found that increased displacement behavior not only correlates with a subjective feeling state of anxiety and negative affect but also gives more veridical information about the subjects emotional state than verbal statements and facial expression. The measurement of displacement activities may be a useful complement to the physiological and psychological studies aimed at analyzing the correlates and consequences of stress.

Early Trauma and Increased Risk for Physical Aggression during Adulthood: The Moderating Role of MAOA Genotype

Previous research has reported that a functional polymorphism in the monoamine oxidase A (MAOA) gene promoter can moderate the association between early life adversity and increased risk for violence and antisocial behavior. In this study of a combined population of psychiatric outpatients and healthy volunteers (N = 235), we tested the hypothesis that MAOA genotype moderates the association between early traumatic life events (ETLE) experienced during the first 15 years of life and the display of physical aggression during adulthood, as assessed by the Aggression Questionnaire. An ANOVA model including gender, exposure to early trauma, and MAOA genotype as between-subjects factors showed significant MAOA×ETLE (F1,227 = 8.20, P = 0.005) and gender×MAOA×ETLE (F1,227 = 7.04, P = 0.009) interaction effects. Physical aggression scores were higher in men who had experienced early traumatic life events and who carried the low MAOA activity allele (MAOA-L). We repeated the analysis in the subgroup of healthy volunteers (N = 145) to exclude that the observed G×E interactions were due to the inclusion of psychiatric patients in our sample and were not generalizable to the population at large. The results for the subgroup of healthy volunteers were identical to those for the entire sample. The cumulative variance in the physical aggression score explained by the ANOVA effects involving the MAOA polymorphism was 6.6% in the entire sample and 12.1% in the sub-sample of healthy volunteers. Our results support the hypothesis that, when combined with exposure to early traumatic life events, low MAOA activity is a significant risk factor for aggressive behavior during adulthood and suggest that the use of dimensional measures focusing on behavioral aspects of aggression may increase the likelihood of detecting significant gene-by-environment interactions in studies of MAOA-related aggression.

Primate displacement activities as an ethopharmacological model of anxiety

Using a within-subject cross-over, vehicle-controlled design, we investigated the acute effects of benzodiazepine receptor ligands with different mechanisms of action on the displacement activities (scratching, self-grooming, and body shake) of seven male macaques living in social groups. Our aim was to test the discriminative validity of displacement activities as an ethopharmacological model of anxiety. Subjects were given i.m. lorazepam (0.10, 0.20, 0.25 mg/ kg) and FG 7142 (0.1, 0.3, 1.0 mg/kg). The frequency of displacement activities was decreased by the anxiolytic lorazepam and increased by the anxiogenic FG 7142 in a dose-dependent manner. Displacement activities were apparently more sensitive to anxiolytic treatment than other behavior patterns indicative of an anxiety state (i.e., visual scanning of the social environment and fear responses directed to dominant males). These results suggest that primate displacement activities are a valid ethopharmacological model of anxiety.

Insecure Attachment and Alexithymia in Young Men with Mood Symptoms

According to attachment theorists, affect regulation and quality of attachment are closely linked. As a personality trait associated with deficits in the cognitive processing and regulation of affects, alexithymia has been hypothesized to correlate with insecure attachment. To test this hypothesis, we studied the relationships between alexithymia, adult attachment style, and retrospective memories of separation anxiety symptoms during childhood in 100 young men with clinically significant mood symptoms. The most common DSM-IV diagnosis (N = 72) was adjustment disorder with depressed mood, with anxiety, or with mixed anxiety and depressed mood. Each participant completed the Twenty-Item Toronto Alexithymia Scale (TAS-20), the Beck Depression Inventory (BDI), the state form of the State-Trait Anxiety Index (STAI), the Attachment Style Questionnaire (ASQ), the Relationship Questionnaire (RQ), and the Separation Anxiety Symptom Inventory (SASI). Alexithymic traits were more pronounced in those participants who had patterns of insecure attachment and who reported more severe symptoms of separation anxiety during childhood, independently of the severity of their current anxiety and depressive symptoms. Among the subgroup of participants with insecure attachment styles, those with preoccupied or fearful patterns had a higher prevalence of alexithymia (65% and 73%, respectively) than those with a dismissing pattern (36%). These data suggest a role for early developmental factors in the etiology of alexithymia

Gender differences in vulnerability to social stress: A Darwinian perspective

This article offers a theoretical framework based on evolutionary thinking designed to clarify relationships between social stress and mental illness, including the origin of gender differences in vulnerability to stress. From a Darwinian perspective, stress is an interference with evolved behavioral strategies. Human behavior is organized around the pursuit of biological goals, and any social event that interferes with these evolved strategic goals may constitute a stressor. The response to such interference -- the stress response -- is made up of physiological, psychological and behavioral components. These components determine how individuals deal with those social events that were likely to reduce inclusive fitness in the ancestral environment. Evolved gender differences in commitment to goals play a role in determining individual differences in response to stressors. When a social stressor interferes with achieving a biological goal, its harmful impact will depend primarily on the importance of the goal to an individual, and the importance assigned to different goals by an individual does not depend exclusively on personal variables and cultural values. Two evolutionary theories are relevant to gender differences in vulnerability to social stress: sexual selection theory and life history theory. Clinical data from patients suffering from depression triggered by social stress are reviewed to test predictions derived from these theories.

Early separation anxiety and adult attachment style in women with eating disorders.

OBJECTIVE To ascertain whether women with eating disorders have a higher frequency of separation anxiety symptoms in childhood, and a higher prevalence of insecure styles of adult attachment, compared with healthy women. METHODS The Separation Anxiety Symptom Inventory (SASI) and the Attachment Style Questionnaire (ASQ) were administered to 78 women with eating disorders and 64 healthy women. RESULTS Compared with control women, women with eating disorders reported more severe symptoms of separation anxiety during childhood, and scored higher on the ASQ scales, reflecting insecure styles of adult attachment. Early separation anxiety and insecure attachment were not correlated with age of onset or illness duration. The diagnostic subgroup was not associated with a specific style of insecure attachment: compared with control women, both anorexic and bulimic women scored higher on the ASQ scales reflecting anxious attachment, but not on the scales reflecting avoidant attachment. CONCLUSIONS The results confirm the link between eating disorders and insecure attachment that has been found in previous studies, and extend it to childhood symptoms of separation anxiety.

Decreased plasma adiponectin concentration in major depression.

Adiponectin is the most abundant adipose-derived plasma protein. Recently adiponectin levels have been linked to most variables of metabolic syndrome and conventional risk factors for cardiovascular disease. However, its relation with major depression is yet unclear. We evaluated plasma adiponectin levels in 32 first-episode drug-naïve major depression (DSM-IV-TR) patients without conventional risk factors for cardiovascular disease and 32 matched healthy subjects. Major depression patients displayed lower adiponectin plasma levels compared to controls (P<0.01). Adiponectin significantly correlated with depression severity, as assessed by HAM-D (rho=0.83, P<0.001). This study shows decreased plasma adiponectin concentrations in major depression patients and relates adiponectinemia reduction to major depression severity.

Early trauma and adult obesity: Is psychological dysfunction the mediating mechanism?

Several studies have shown that physical and/or sexual abuse during childhood may lead to the development of obesity later in life. Despite these consistent findings, the mechanism for the increased risk of obesity following developmental trauma is unknown. It has been suggested that psychological dysfunction, including the presence of disordered eating behavior, may account for the added risk of adult obesity. To test this hypothesis, we analyzed the prevalence and severity of different types of early traumatic life events, assessed the presence of co-existing psychiatric disorders and measured adult attachment style in a sample of 200 subjects including non-obese healthy volunteers and obese participants undergoing a psychiatric assessment to determine suitability for bariatric surgery. Participants who scored higher on a scale measuring the severity of traumatic events experienced during the first 15years of their lives were more likely to be obese at the time of testing. The exclusion of the participants who experienced physical and/or sexual abuse did not change the results of statistical analysis. Severity of early trauma remained a significant predictor of adult obesity when the influence of psychiatric diagnosis and anxious attachment was taken into account. These findings suggest that: (1) not only sexual or physical abuse but also less severe forms of early-life stress are linked to the development of obesity later in life; and (2) psychological dysfunction is not the only mechanism mediating the elevated risk of obesity in persons exposed to early-life trauma.

Body dissatisfaction in women with eating disorders: relationship to early separation anxiety and insecure attachment.

Objective: It has been suggested that an insecure style of attachment may be one of the factors implicated in the etiology of body dissatisfaction, which, in turn, is a risk factor for eating disorders. The present study analyzed the association among early separation anxiety, insecure attachment, and body dissatisfaction in a clinical sample of 96 women with anorexia nervosa (n = 31) or bulimia nervosa (n = 65). Methods: Body dissatisfaction was measured using the Body Shape Questionnaire (BSQ), early separation anxiety was measured using the Separation Anxiety Symptom Inventory (SASI), and adult attachment style was measured using the Attachment Style Questionnaire (ASQ). Results: In both anorectic and bulimic women, BSQ scores were strongly correlated with SASI and ASQ scores. In a hierarchical regression model controlling for the confounding effects of body mass index and depressive symptoms, early separation anxiety and preoccupied attachment emerged as significant predictors of high levels of body dissatisfaction. Conclusions: Based on the cross-sectional findings of this study, insecure attachment appears to be a consistent correlate of negative body image evaluations in women with either anorexia nervosa or bulimia nervosa. If future prospective studies will confirm that an insecure style of attachment plays a role in promoting the development of body dissatisfaction, prevention and treatment of disordered eating pathology might be enhanced by focusing greater attention on attachment relationships. AN = anorexia nervosa; ASQ = Attachment Style Questionnaire; BDI = Beck Depression Inventory; BN = bulimia nervosa; BMI = body mass index; BSQ = Body Shape Questionnaire; SASI = Separation Anxiety Symptom Inventory.