Penelope J. Davis

Mechanisms underlying aggressive and hostile behavior in amphetamine users

Purpose of review To review current evidence linking amphetamine use with aggression and to consider possible factors that might underlie this association. Recent findings Although evidence that amphetamine use is related to increased levels of aggression continues to grow, the underlying processes or mechanisms remain somewhat elusive. In this review, three possible underlying factors are considered. Neurotoxic, pharmacological effects of amphetamine on the dopaminergic and serotonergic systems are related to aggressive, hostile behavior in both animal and human studies. Of particular interest is the converging evidence that amphetamine use is related to impairment in executive functions (including self-control) that are regulated by the prefrontal cortex. Taken together, these findings suggest that amphetamine users may have an impaired capacity to control or inhibit aggressive impulses. Furthermore, high levels of impulsivity related to amphetamine use may also play a role. Finally, amphetamine use is associated with increased positive symptoms of psychosis, particularly paranoia, that contribute to a perception of the environment as a hostile, threatening place. Summary Taken separately, each of these factors may lead to an increase in aggression with increased use of amphetamine, but their interactive or synergistic effects may be particularly problematic.

The positive effects of mindfulness on self-esteem

Positive psychological research has clearly highlighted the importance of investigating factors that contribute to well-being. One factor contributing greatly to psychological well-being is mindfulness, which has been related to a wide range of positive outcomes, including healthy self-esteem. Here, we present two studies that aim to extend prior research on mindfulness and self-esteem. In Study 1, we propose and test a theoretically derived model of the role that mindfulness plays in the prediction of self-esteem and life satisfaction. Four facets of mindfulness significantly predicted increased self-esteem, which in turn predicted overall life satisfaction. In Study 2, we extended this study by examining the direct effects of a brief mindfulness induction on state self-esteem, and found that experimentally enhancing state mindfulness led to an increase in state self-esteem. The two studies presented clearly demonstrate that mindfulness and self-esteem are related, and, importantly, that mindfulness training has direct positive effects on self-esteem.

Repressor Personality Styles and EEG Patterns Associated with Affective Memory and Thought Suppression

Repressive personality style has often been identified as an important variable governing a variety of individual differences. There is debate, however, concerning the mechanisms by which this style is expressed. One hypothesis suggests that threatening information, after encoding, is suppressed from awareness. Another theory maintains that threatening information is diverted from awareness at a “preconscious” level. The experiment described here attempted to address this debate. Twenty undergraduate subjects selected on the basis of their scores on the Taylor Manifest Anxiety scale and the Marlowe-Crowne Social Desirability scale participated. The subjects represented four personality groups based on the intersection of high and low scores on the two tests. Individuals showing low anxiousness-high social desirability were identified as repressors. EEG, cardiovascular, and self-report data were recorded form subjects as they engaged in recall, elaboration, and suppression of positive and negative memories. Results of the analyses of these data indicated that the personality groups differed widely in EEG theta, alpha and beta activity during the completion of these tasks. The pattern of these findings suggest that subjects using a repressive coping style exhibit EEG activity associated with anxiety and also an absence of cognitive activity when faced with the recall of negative memories.

Craving as a predictor of treatment outcomes in heavy drinkers with comorbid depressed mood

Alcohol and depression comorbidity is high and is associated with poorer outcomes following treatment. The ability to predict likely treatment response would be advantageous for treatment planning. Craving has been widely studied as a potential predictor, but has performed inconsistently. The effect of comorbid depression on cravings predictive performance however, has been largely neglected, despite demonstrated associations between negative affect and craving. The current study examined the performance of craving, measured pre-treatment using the Obsessive subscale of the Obsessive Compulsive Drinking Scale, in predicting 18-week and 12-month post-treatment alcohol use outcomes in a sample of depressed drinkers. Data for the current study were collected during a randomized controlled trial (Baker, Kavanagh, Kay-Lambkin, Hunt, Lewin, Carr, & Connolly, 2010) comparing treatments for comorbid alcohol and depression. A subset of 260 participants from that trial with a Timeline Followback measure of alcohol consumption was analyzed. Pre-treatment craving was a significant predictor of average weekly alcohol consumption at 18 weeks and of frequency of alcohol binges at 18 weeks and 12 months, but pre-treatment depressive mood was not predictive, and effects of Baseline craving were independent of depressive mood. Results suggest a greater ongoing risk from craving than from depressive mood at Baseline.

The association between state attachment security and state Mindfulness.

Recent research suggests that attachment and mindfulness are related, though the nature of this association is unclear. Here we present two studies examining whether there is a causal relationship between state attachment and state mindfulness. Study 1 investigated the effects of experimentally increasing state mindfulness on state attachment security. State mindfulness was successfully enhanced, but this led to no change in state attachment security. Study 2 investigated the effects of experimentally enhancing state attachment security on state mindfulness. State attachment security was successfully enhanced, but this did not lead to any change in state mindfulness. These findings suggest that there is not a direct, immediate causal relationship between state attachment and state mindfulness as a result of brief experimental manipulations. Future research should examine these associations in longer term interventions.

Interpretation of congruent and incongruent affective communications in paranoid schizophrenia

OBJECTIVES It was hypothesized that people with paranoid schizophrenia would differ from depressed and normal participants in their interpretation of complex communications in which the affect conveyed verbally was either congruent or incongruent with the affect conveyed non-verbally. DESIGN A 3 (group) x 3 (positive, negative, neutral facial expression) x 3 (positive, negative, neutral verbal content) experimental design was used. There were eight participants per group, and the paranoid and depressed groups comprised inpatients in an acute psychiatric facility for either their first or second psychiatric episode. METHODS Participants, tested individually, were asked to interpret the affect conveyed by the various communications presented. RESULTS All participants interpreted most of the communications in a similar way. Paranoid schizophrenia patients, however, differed in their interpretation of communications in which negative feelings were expressed verbally. In contrast to both the normal and depressed groups, the paranoid schizophrenia group interpreted these communications as virtually devoid of any affect whatsoever. CONCLUSIONS Paranoid schizophrenia patients show an information-processing bias in response to communications involving both congruent and incongruent negative verbal content. It is not obvious why the bias observed would be specific to negative verbal messages and not extend to negative non-verbal messages. Replication and further study are required.

Mindfulness for Cultivating Self-Esteem

Self-esteem is said to be a fundamental and pervasive human need. Humans are motivated to maintain high self-esteem and engage in efforts to protect their self-esteem when it comes under threat. High self-esteem is a positive personal resource and is generally related to a wide range of positive life outcomes. It is therefore important to consider factors that may enhance self-esteem. Here, we argue that mindfulness may be useful to cultivate self-esteem and, in particular, secure self-esteem as opposed to fragile high self-esteem. We begin with an overview of the benefits of healthy self-esteem and costs of low self-esteem. We then argue that individuals high in dispositional mindfulness may have greater capacity for secure high self-esteem. Evidence from clinical and experimental studies examining associations between mindfulness and self-esteem is reviewed next. We conclude with a discussion of the use of mindfulness-based interventions for the cultivation of healthy self-esteem and an outline of directions for future research.

Toward a Psychology of Singlehood: An Attachment-Theory Perspective on Long-Term Singlehood

The number of people who remain single for long periods of time is sizeable and growing in the Western world, yet they are largely ignored in psychological theory and research. In this article, we review psychological and sociological evidence that long-term singles are a heterogeneous group of individuals, outline an attachment-theoretical model of long-term singlehood, and review direct and indirect empirical evidence suggestive of at least three distinct subgroups of long-term singles: (a) singlehood due to attachment-system deactivation, (b) singlehood due to attachment-system hyperactivation, and (c) singlehood as a secure personal choice. Our aim is to highlight long-term singles as a population that merits scientific study and to provide a foundation on which future research can build.