Sara Pieters

Testosterone increases amygdala reactivity in middle-aged women to a young adulthood level

Testosterone modulates mood and sexual function in women. However, androgen levels decline with age, which may relate to the age-associated change in sexual functioning and the prevalence of mood and anxiety disorders. These effects of testosterone are potentially mediated by the amygdala. In the present study, we investigated whether the age-related decline in androgen levels is associated with reduced amygdala activity, and whether exogenous testosterone can restore amygdala activity. Healthy young and middle-aged women participated during the early follicular phase of the menstrual cycle, and amygdala responses to biologically salient stimuli were measured with functional magnetic resonance imaging (fMRI). Androgen levels were lower in middle-aged than young women, which was associated with decreased amygdala reactivity. Endogenous testosterone levels correlated positively with amygdala reactivity across the young and middle-aged women. The middle-aged women received a single nasal dose of testosterone in a double-blind, placebo-controlled, crossover manner, which rapidly increased amygdala reactivity to a level comparable to the young women. The enhanced testosterone levels correlated positively with superior frontal cortex responses and negatively with orbitofrontal cortex responses across individuals, which may reflect testosterone-induced changes in amygdala regulation. These results show that testosterone modulates amygdala reactivity in women, and suggest that the age-related decline in androgen levels contribute to the decrease in amygdala reactivity.

Puberty-dependent sleep regulation and alcohol use in early-adolescents

BACKGROUND Research has shown a bi-directional relation between alcohol use and sleep regulation in adults. Much less is known about this association in early adolescents, while profound puberty-dependent transitions regarding sleep patterns take place in early adolescence. Moreover, puberty has been associated with an increase in alcohol use of adolescents. METHODS In this study, we investigated the associations between pubertal development, sleep preference, sleep problems, and alcohol use in 431 early adolescents (mean age: 13.66). Second, it was studied whether the associations changed when controlling for adolescent internalizing and externalizing problems. Furthermore, we included gender as a moderator on all the associations. RESULTS Results showed that pubertal development was positively associated with sleep problems and more evening-type tendencies (e.g., favoring later bedtimes), which in turn were positively related to alcohol use. Underlying psychopathology, gender and educational level did not change these relationships. CONCLUSIONS From this study, it can be concluded that both puberty and sleep regulation are important factors in explaining alcohol use in early adolescence.

The Moderating Role of Working Memory Capacity and Alcohol-Specific Rule-Setting on the Relation Between Approach Tendencies and Alcohol Use in Young Adolescents

BACKGROUND Dual process models of alcohol addiction propose that the transition from normative alcohol consumption to heavy drinking is the result of an imbalance in interplay between relatively impulsive or automatic and reflective or controlled processes. The current study examines whether impulsive and reflective processes are also detectable in a sample of adolescents with limited alcohol use. METHODS Specifically, we tested the interaction between alcohol approach tendencies and 2 types of reflective processes, working memory capacity (WMC) and alcohol-specific rule-setting, on changes in alcohol use of 238 young adolescents (mean age: 13.82 years). Gender differences in these associations were also explored. RESULTS Results showed that WMC did not moderate the relation between approach tendencies and subsequent alcohol use, whereas rule-setting did, with stronger associations between approach tendencies and alcohol use for male adolescents reporting more permissive parents than male adolescents with parents enforcing stricter rules involving alcohol use. Associations between approach tendencies and subsequent alcohol use did not emerge for female adolescents. CONCLUSIONS Results indicate that even in a sample of adolescents with limited drinking experience, automatic processes are positively associated with alcohol use for male adolescents that are not motivated by parents to control their drinking.

The effect of the OPRM1 and DRD4 polymorphisms on the relation between attentional bias and alcohol use in adolescence and young adulthood.

BACKGROUND The incentive sensitization theory posits that in the transition from sporadic to problematic alcohol use, the incentive value of alcohol increases (wanting) while its hedonic effects (liking) do not change or decreases. The effect of the OPRM1 c.118A>G polymorphism, associated with liking and wanting, and the DRD4-VNTR polymorphism, related to wanting, on the relation between attentional bias and alcohol use was investigated. METHODS A total of 195 young adolescents (Study 1) and 86 young adult male heavy drinkers (Study 2) completed a visual probe test. Saliva samples were collected to test both polymorphisms. RESULTS In Study 1, attentional bias was positively associated with adolescent alcohol use only for OPRM1 G-allele carriers. In Study 2, attentional bias was positively associated with problem drinking for carriers of a DRD4 long allele. DISCUSSION It is tentatively proposed that an attentional bias for alcohol is related most strongly to liking and wanting in early adolescents, while in young adults, an attentional bias may reflect wanting. In addition, individual differences associated with two both genetic markers should be taken into account when examining the relation between attentional bias and alcohol use.

Impulsive and reflective processes related to alcohol use in young adolescents

Background: Dual process models suggest that the development of addictive behaviors is the result of interplay between impulsive and reflective processes, modulated by boundary conditions such as individual or situational factors. Empirical support for this model has been repeatedly demonstrated in adult samples [for a meta-analysis, see Ref. (1)]. The purpose of this study was to test these processes as they relate to emerging alcohol use in adolescents. Specifically, the interactive effects of several measures of impulsive and reflective processes and working memory capacity (WMC) are examined as predictors of changes in alcohol use among adolescents. It was expected that measures of reflective processes would better predict changes in alcohol use than measures of impulsive processes. Moreover, it was anticipated that WMC would moderate the relation between alcohol-specific impulsive and reflective processes and changes in adolescent alcohol use. Methods: The sample consisted of 427 adolescents (47.7% male) between 12 and 16 years of age (M = 13.96, SD = 0.78) who reported drinking alcohol at least once. Four measures of impulsive processes were included. Attentional bias for alcohol was assessed with a Visual Probe Test; approach bias toward alcohol was assessed with a Stimulus Response Compatibility (SRC) Test; and memory associations with alcohol were assessed with an Implicit Association Test (IAT) and a Word Association Test. Two measures of reflective measures were included: positive and negative expectancies. WMC was measured using a Self-Ordered Pointing Task. Results: Results showed that positive expectancies predicted changes in alcohol use, but this effect was qualified by an interaction with IAT scores. Moreover, SRC scores predicted changes in alcohol use only when negative expectancies were low. Attentional bias and word association scores did not predict changes in alcohol use. The relations between alcohol-specific processes or reflective processes and alcohol use were not moderated by WMC. Conclusion: Although there is empirical evidence for the validity of the model in predicting heavier alcohol use in adolescents, or alcohol abuse and dependence in adults, these observations do not generalize to a sample of normative, early adolescents. More specifically, results indicated that reflective processes are more important predictors of changes in alcohol use than impulsive process during adolescence.

Acute Stress Increases Implicit Depression and Decreases Implicit Self-Esteem

According to cognitive theories, internalizing problems are the result of the activation of dysfunctional attitudes (e.g., negative self-thoughts) in memory in response to stressful life events. Dual process models posit that associative and reflective cognitive processes may respond differently to stressful life events and may affect the development of psychopathology. According to these models, self-relevant stimuli activate both associative and reflective processes. However, previous research has focused mainly on reflective processes using explicit assessment instruments. The main aim of the present study was to examine the effect of acute stress on both associative and reflective cognitive processes by using implicit and explicit measures of self-esteem and depression. Participants were 95 university students (M = 23.3 years, SD = .37, 79 females). Implicit and explicit measures of self-esteem and depression were administered before and after a stress-induction procedure. The results showed that acute stress increased implicit depression (p < .01) and decreased implicit self-esteem (p < .05) but did not affect explicit measures of self-esteem and depression (p-values = .44). Together, these findings offer new insights into the relationship of stress with implicit and explicit attitudes and provide experimental support for dual process models.

Influence of Smoking Cues in Movies on Children’s Beliefs About Smoking

OBJECTIVE: Experimental research has revealed that short exposure to movie smoking affects beliefs about smoking in adolescents. In this study, we tested that association in children. METHODS: In 2 experiments, participants were exposed to either a cartoon or family-oriented movie and randomly assigned to 20-minute segments with or without smoking characters. Data collection took place at elementary schools. A total of 101 children (8–10 years; 47.5% boys) were exposed to a cartoon, and in a second experiment, 105 children (8–11 years; 56.2% boys) were exposed to a family-oriented movie. Beliefs about smoking (assessed by questionnaire) and implicit associations toward smoking (single target implicit association task) were assessed after watching the movie. RESULTS: The majority of both samples of children viewed smoking unfavorably. Exposure to movie smoking had no effect on implicit associations toward smoking when experiments were analyzed separately or if the results were combined. For smoking beliefs, effects were again small and only statistically significant for social norms regarding smoking. CONCLUSIONS: Short-term exposure to smoking in cartoon and family-oriented movies had little immediate impact on beliefs about smoking in preadolescent children, but a significant cumulative impact on norms cannot be ruled out.