Interoceptive fear conditioning as a learning model of panic disorder: an experimental evaluation using 20% CO(2)-enriched air in a non-clinical sample

Despite the role afforded interoceptive fear conditioning in etiologic accounts of panic disorder, there are no good experimental demonstrations of such learning in humans. The aim of the present study was to evaluate the interoceptive conditioning account using 20% carbon dioxide (CO(2))-enriched air as an interoceptive conditioned stimulus (CS) (i.e., physiologically inert 5-s exposures) and unconditioned stimulus (US) (i.e., physiologically prepotent 15-s exposures). Healthy participants (N=42) were randomly assigned to one of three conditions: a CS-only, contingent CS-US pairings, or unpaired/non-contingent CS and US presentations. Electrodermal and self-report (e.g., distress, fear) served as indices of conditioned emotional responding. Results showed greater magnitude electrodermal and evaluative fear conditioning in the paired relative to the CS-only condition. The explicitly unpaired condition showed even greater electrodermal and evaluative responding during acquisition, and marked resistance to extinction. The latter results are consistent with the possibility that the unpaired procedure constituted a partial reinforcement procedure in which CO(2) onset was paired with more extended CO(2) exposure on 50% of the trials. Overall, the findings are consistent with contemporary learning theory accounts of panic.     

Evaluating the invariance and validity of the structure of dysfunctional attitudes in an adolescent population

Form A of the Dysfunctional Attitude Scale (DAS-A), a self-report measure of depressive beliefs, is widely used to test Beck's cognitive model of depression. The present study is the first to evaluate the DAS-A factor structure in an adolescent population of 542 high school juniors and the first to examine a hierarchical model. Findings support the existence of a hierarchical structure consisting of two conceptually meaningful group factors (Dysfunctional Attitudes About Achievement and Dysfunctional Attitudes About Needing Approval), a method factor consisting of reverse-worded items, and a general factor, which accounts for 65% of the variance in total scores. The general factor is related to sociotropy, autonomy, and neuroticism, whereas the Dysfunctional Attitudes About Achievement and Dysfunctional Attitudes About Needing Approval factors demonstrate convergent and discriminant validity with respect to autonomy and sociotropy. The structure displays partial metric invariance in female and male students as well as in Caucasian and Non-Caucasian students.     

Are anxiety and depression just as stable as personality during late adolescence? Results from a three-year longitudinal latent variable study

Although considerable evidence shows that affective symptoms and personality traits demonstrate moderate to high relative stabilities during adolescence and early adulthood, there has been little work done to examine differential stability among these constructs or to study the manner in which the stability of these constructs is expressed. The present study used a three-year longitudinal design in an adolescent/young adult sample to examine the stability of depression symptoms, social phobia symptoms, specific phobia symptoms, neuroticism, and extraversion. When considering one-, two-, and three-year durations, anxiety and personality stabilities were generally similar and typically greater than the stability of depression. Comparison of various representations of a latent variable trait-state-occasion (TSO) model revealed that whereas the full TSO model was the best representation for depression, a trait stability model was the most parsimonious of the best-fitting models for the anxiety and personality constructs. Over three years, the percentages of variance explained by the trait component for the anxiety and personality constructs (73-84%) were significantly greater than that explained by the trait component for depression (46%). These findings indicate that symptoms of depression are more episodic in nature, whereas symptoms of anxiety are more similar to personality variables in their expression of stability.     

Post-extinction conditional stimulus valence predicts reinstatement fear: Relevance for long-term outcomes of exposure therapy

Exposure therapy for anxiety disorders is translated from fear conditioning and extinction. While exposure therapy is effective in treating anxiety, fear sometimes returns after exposure. One pathway for return of fear is reinstatement: unsignaled unconditional stimuli following completion of extinction. The present study investigated the extent to which valence of the conditional stimulus (CS+) after extinction predicts return of CS+ fear after reinstatement. Participants (N = 84) engaged in a differential fear conditioning paradigm and were randomised to reinstatement or non-reinstatement. We hypothesised that more negative post-extinction CS+ valence would predict higher CS+ fear after reinstatement relative to non-reinstatement and relative to extinction retest. Results supported the hypotheses and suggest that strategies designed to decrease negative valence of the CS+ may reduce the return of fear via reinstatement following exposure therapy.     

Changes in Behaviour and Body Weight Following a Single or Double Social Defeat in Rats

In a series of experiments, the consequences of a single and double social conflict on various behaviours and body weight in rats were studied. Animals were subjected to social defeat by placing them into the territory of an aggressive male conspecific for one hour, either once, or twice at the same time on two consecutive days. To assess the consequences of social defeat, three experiments were performed with independent groups of rats. In the first experiment, an open field test was performed two days after the last conflict. Locomotor activity was strongly reduced after social defeat. There were no differences between the single and double defeat group. To assess the effects of social defeat on subsequent social behaviour, a second experiment was performed in which experimental animals were confronted with an unfamiliar non-aggressive rat two days after a single or double conflict. Social defeat resulted in a reduction of social contact with the unfamiliar conspecific. There was no difference between the single and double conflict group. In the third experiment, the effects of social conflict on food intake, body weight and saccharine preference were measured. Food intake was not affected after a single conflict, but in the double conflict group food intake was decreased for several days. Body weight gain was decreased after both single and double social defeat. The decrease was stronger in the double conflict group. Water intake and saccharine preference were not significantly affected. This study revealed that social defeat in rats causes pronounced changes in various behaviours and body weight. Different aspects of behaviour are differentially affected by defeat with respect to the magnitude and time course of the changes induced. Moreover, different behavioural parameters are differentially sensitive to repetition of the stressor.     

Psychological skills and mindfulness training effects on the psychological wellbeing of undergraduate music students: An exploratory study

This study explored the efficacy of psychological skills and mindfulness training intervention on the psychological wellbeing of undergraduate music students. Participants were undergraduate music students (n = 36) from the Department of Music at a South African university, 21 of whom were elected to take the psychological skills and mindfulness training intervention. Data on their self-reported psychological wellbeing, psychological skills, mindfulness and performance anxiety levels were collected pre-and post-intervention. The analysis applied non-parametric procedures to determine changes in students’ psychological wellbeing after the seven-week intervention programme. Findings suggest improvements in psychological wellbeing, psychological skills, mindfulness and performance anxiety with training. Psychological skills and mindfulness training may have benefits to the psychological wellbeing of music students.