Richard A. Depue

A neurobehavioral model of affiliative bonding: implications for conceptualizing a human trait of affiliation.

Because little is known about the human trait of affiliation, we provide a novel neurobehavioral model of affiliative bonding. Discussion is organized around processes of reward and memory formation that occur during approach and consummatory phases of affiliation. Appetitive and consummatory reward processes are mediated independently by the activity of the ventral tegmental area (VTA) dopamine (DA)-nucleus accumbens shell (NAS) pathway and the central corticolimbic projections of the u-opiate system of the medial basal arcuate nucleus, respectively, although these two projection systems functionally interact across time. We next explicate the manner in which DA and glutamate interact in both the VTA and NAS to form incentive-encoded contextual memory ensembles that are predictive of reward derived from affiliative objects. Affiliative stimuli, in particular, are incorporated within contextual ensembles predictive of affiliative reward via: (a) the binding of affiliative stimuli in the rostral circuit of the medial extended amygdala and subsequent transmission to the NAS shell; (b) affiliative stimulus-induced opiate potentiation of DA processes in the VTA and NAS; and (c) permissive or facilitatory effects of gonadal steroids, oxytocin (in interaction with DA), and vasopressin on (i) sensory, perceptual, and attentional processing of affiliative stimuli and (ii) formation of social memories. Among these various processes, we propose that the capacity to experience affiliative reward via opiate functioning has a disproportionate weight in determining individual differences in affiliation. We delineate sources of these individual differences, and provide the first human data that support an association between opiate functioning and variation in trait affiliation.

A behavioral paradigm for identifying persons at risk for bipolar depressive disorder: a conceptual framework and five validation studies.

In an attempt to study predisposition to bipolar manic-depressive disorder, we developed a behavioral paradigm to identify persons at risk for various forms of the disorder. We provide a theoretical discussion for denning bipolar disorder within the broader framework of common human diseases and then employ this framework to derive dimensions of bipolar disorder that define its distinctness from the normal phenotype. These dimensions (behavioral and nonbehavioral features of disorder) are operationalized in the form of a self-report inventory which estimates the probability that an individual is at risk. Five external validation studies using nontest criteria are presented, including interview, roommate, family history, clinical characteristics, and longitudinal mood rating investigations. Results indicate that the inventory serves as a promising first-stage case identification procedure for bipolar disorder when employed in a research context.

Facilitation of working memory in humans by a d2 dopamine receptor agonist

Recent studies on the neurobiology of cognition have focused on the ability of the prefrontal cortex (PFC) to support processes of working memory, i.e, mnemonic processes by which information relevant for a correct response is temporarily maintained to be reevaluated or updated on a trial-by-trial basis. Of most recent interest is the role played by dopamine (DA) in spatial working memory processes of the principal sulcal region of the PFC. Although D1 DA receptors appear to modulate these mnemonic processes in monkeys, several lines of research suggest that D2 DA receptors could also be relevant to cognitive functions. Therefore, we assessed the effects of a specific D2 receptor agonist (bromocriptine) and placebo on visuospatial delayed response performance in human subjects. During delay periods of 0 or 8 sec, subjects were required to remember the spatial location of rapidly presented visual cues displayed in peripheral vision within a 360 circumference. The extent to which D2 receptor activation by bromocriptine facilitated working memory in the 8sec delay condition relative to placebo performance was assessed. As a means of providing validation of bromocriptines D2 receptor effect, maximum inhibition of prolactin (PRL) secretion, which is inhibited specifically by activation of D2 receptor sites, was determined. Additionally, tasks having no working memory component were administered to rule out nonspecific effects of bromocriptine on sensory, arousal, attentional, and motor factors. Results demonstrated a significant facilitatory effect of bromocriptine on spatial delayed response performance (i.e., 8sec delay performance). Results could not be explained by nonspecific effects of bromocriptine. Thus, findings of this study suggest that spatial working memory is facilitated by D2 receptor activation. The role that DA may play in human cognitive processes is discussed within the larger theoretical framework of DAs general role in the facilitation of goal-directed behavior. In the case of cognition, DA may facilitate processes that serve to guide motivated behavior through complex environments.

Dopamine and the structure of personality: Relation of agonist-induced dopamine activity to positive emotionality.

Modern trait theories of personality include a dimension reflecting positive emotionality (PE) based on sensitivity to signals of incentive-reward. In animals, responsivity within an emotional system analog of PE is dependent on brain dopamine (DA) activity. To determine whether human PE trait levels are also associated with central DA, effects of a specific DA D2 receptor agonist were assessed in Ss who were widely distributed along the trait dimension of PE. The degree of agonist-induced reactivity in two distinct central DA indices was strongly and specifically associated with trait levels of PE, but not with other personality traits. The results suggest that the trait structure of personality may be related to individual differences in brain DA functioning.

General Behavior Inventory Identification of Unipolar and Bipolar Affective Conditions in a Nonclinical University Population

Validated the General Behavior Inventory (GBI), revised to identify unipolar as well as bipolar affective conditions, in a nonclinical sample (n = 201) against naive, interview-derived diagnoses. For bipolar and unipolar conditions, respectively, the GBI had high positive (.94, .87) and negative (.99, .93) predictive power with the effect of prevalence considered, adequate sensitivity (.78, .76), high specificity (.99, .99), and adequate selection ratios for sampling of affective and nonaffective subjects from nonclinical populations for research purposes. The utility of the GBI in several different research contexts is discussed.

Regional electroencephalographic asymmetries in bipolar seasonal affective disorder before and after exposure to bright light

Electroencephalographic (EEG) asymmetries found in nonseasonal depression were examined in seasonal affective disorder before and after bright-light exposure. Subjects with seasonal depression demonstrated the expected pattern of frontal asymmetry both when depressed and following light-induced remission. Right-hemisphere EEG coherence, by contrast, served as a state-dependent indicator of seasonal depression.

Neurobiological factors in personality and depression

There is very little empirical work that directly assesses the neurobiological association of personality superfactors with the liability to depression. Therefore, as a means of providing a framework for future research, this article outlines the putative neurobiological foundation of three major personality superfactors: positive emotionality or extraversion, constraint or psychoticism, and negative emotionality or neuroticism. The neurobiology of these superfactors, particularly the central dopamine, serotonin, and norepinephrine projection systems, respectively, is derived largely from animal biobehavioral research, although human work is discussed where available. In an attempt to explore the association of this framework to depression, extreme quantitative variation in the resulting neurobiological systems, alone and in interaction with each other, is discussed in terms of different forms of depression and of modification of the phenotype and course of depression. The effects of experience on neurobiological functioning is briefly considered as a therapeutic approach, in lieu of, or in interaction with, pharmacological modulation of behavior.

Differential association of traits of fear and anxiety with norepinephrine- and dark-induced pupil reactivity.

The relation between fear and anxiety remains unclear, though psychometric data strongly suggest they are independent emotional systems. Because central norepinephrine (NE) projection systems are at the core of models of both fear and anxiety, the present experiment explored whether this independence extends to NE functioning. Two different aspects of NE functioning were assessed in a healthy young adult sample (N = 18): pupillary reactivity to (a) a specific NE alpha-1 agonist challenge to assess receptor reactivity and (b) a darkness challenge to assess contributions of central NE. Pupillary reactivity to the former was strongly and specifically related to A. Tellegens (1982) Multidimensional Personality Questionnaire (MPQ) Harm Avoidance scale (i.e., trait fear), whereas the latter was strongly and specifically related to MPQ Negative Emotionality (i.e., trait anxiety). Implications for conceptualizing fear and anxiety as emotional systems are discussed.

Serotonergic functioning correlates with positive and negative affect in psychiatrically healthy males

A large animal literature implicates serotonin (5-HT) in the modulation of positive and negative affective behavior. In contrast, data from human studies almost exclusively emphasize 5-HT modulation of negative emotional processing. However, no previous studies have directly assessed the relation between 5-HT functioning and positive (PA) and negative (NA) affect. The present investigation tested whether individual differences in 5-HT functioning correlate with PA and NA ratings in a group of healthy subjects. Thirty-one psychiatrically healthy males completed separate assessments of affect and 5-HT functioning. Affect was examined with the Positive and Negative Affect Schedule rated three times a day for two work-weeks. 5-HT functioning was indexed by the maximum prolactin response to d,l-fenfluramine. The prolactin response to d,l-fenfluramine demonstrated a significant inverse correlation with mean ratings of both PA (r=−0.49; p<0.005) and NA (r=−0.42; p<0.05). These data provide evidence that 5-HT exerts an inhibitory influence over both PA and NA in humans, such that individual differences in 5-HT functioning inversely correlate with ratings of affect.

Film-induced incentive motivation and positive activation in relation to agentic and affiliative components of extraversion

Abstract Recently we argued that a core process underlying the trait of extraversion is positive incentive motivation, an association that particularly characterizes the agentic as opposed to the affiliative component of extraversion (Depue & Collins, Behavioral and Brain Sciences, 22 , 1–79, 1999). Due to a paucity of methods that specifically induce incentive motivation–positive activation (as opposed to solely amusement and pleasantness), this study developed dynamic film material that activates such subjective experience. Moreover, the films represent three levels of magnitude of induced incentive motivation–positive activation, ranging from minimal to moderate to strong. Therefore, individual differences in film-induced positive activation could be expressed as a stimulus intensity–response function via the slope of positive activation ratings across the range of incentive magnitudes. Film-induced reactivity in positive activation, as opposed to pre-film basal positive activation, was preferentially related to extraversion. Moreover, the slope of post-film positive activation across films, reflecting a stimulus intensity–response function, was more robustly related to overall estimates of extraversion ( r =0.34, p r =0.32, p r =0.18, p =0.09) component of extraversion. The findings suggest that a unitary concept of extraversion may be incorrect, and that further research is necessary to characterize the nature of agentic and affiliative components of the trait. The film method reported herein provides one means of investigating the incentive motivation–positive activation nature of extraversion.