Developmental changes and individual differences in risk and perspective taking in adolescence

Addiction, adolescence, and the integration of control and motivation

The likelihood of initiating addictive behaviors is higher during adolescence than during any other developmental period. The differential developmental trajectories of brain regions involved in motivation and control processes may lead to adolescents' increased risk taking in general, which may be exacerbated by the neural consequences of drug use. Neuroimaging studies suggest that increased risk-taking behavior in adolescence is related to an imbalance between prefrontal cortical regions, associated with executive functions, and subcortical brain regions related to affect and motivation. Dual-process models of addictive behaviors are similarly concerned with difficulties in controlling abnormally strong motivational processes. We acknowledge concerns raised about dual-process models, but argue that they can be addressed by carefully considering levels of description: motivational processes and top-down biasing can be understood as intertwined, co-developing components of more versus less reflective states of processing. We illustrate this with a model that further emphasizes temporal dynamics. Finally, behavioral interventions for addiction are discussed. Insights in the development of control and motivation may help to better understand - and more efficiently intervene in - vulnerabilities involving control and motivation.

Neurobiology of decision making in depressed adolescents: a functional magnetic resonance imaging study

OBJECTIVE

Despite evidence that impaired reward- and risk-related behavior during adolescence can have potentially serious short- and long-term consequences, few studies have investigated the impact of depression on reward-related selection in adolescents. This study examined the relationship between reward-related behavior and prefrontal activations in depressed and healthy adolescents during a decision-making task.

METHOD

A total of 22 adolescents with no personal or family history of psychiatric illness and 22 adolescents with major depressive disorder were administered a monetary, two-option decision-making task, the Wheel of Fortune, using a functional magnetic resonance imaging protocol. The analysis was focused on the selection phase, i.e., the first phase of the decision-making process, which typically includes two more phases, the anticipation of outcome and the feedback.

RESULTS

Similar prefrontal regions were activated in healthy and depressed adolescents during reward-related selection. However, in a contrast involving the selection of high-risk (low-probability/high-magnitude reward) versus equal-risk (50% chance of reward) options, healthy adolescents showed greater activation than patients in the right lateral orbitofrontal cortex (OFC), whereas participants with depression showed greater activation than healthy subjects in the left dorsal OFC and right caudal anterior cingulate cortex. In addition, healthy adolescents, but not participants with depression, showed a negative correlation between high-risk behavior and neuronal activation in prespecified prefrontal regions.

CONCLUSIONS

These results suggest subtle changes in the neural responses to reward selection in depressed adolescents. These findings should be replicated in larger samples, and the association of these neuronal changes with treatment response and prognosis should be examined.

Decision-making under risk in children, adolescents, and young adults

Adolescents often make risky and impulsive decisions. Such behavior has led to the common assumption that a dysfunction in risk-related decision-making peaks during this age. Differences in how risk has been defined across studies, however, make it difficult to draw conclusions about developmental changes in risky decision-making. Here, we developed a non-symbolic economic decision-making task that can be used across a wide age span and that uses coefficient of variation (CV) in reward as an index of risk. We found that young children showed the strongest preference for risky compared to sure bet options of equal expected value, adolescents were intermediate in their risk preference, and young adults showed the strongest risk aversion. Furthermore, children's preference for the risky option increased for larger CVs, while adolescents and young adults showed the opposite pattern, favoring the sure bet more often as CV increased. Finally, when faced with two gambles in a risk-return tradeoff, all three age groups exhibited a greater preference for the option with the lower risk and return as the disparity in risk between the two options increased. These findings demonstrate clear age-related differences in economic risk preferences that vary with choice set and risk. Importantly, adolescence appears to represent an intermediate decision-making phenotype along the transition from childhood to adulthood, rather than an age of heightened preference for economic risk.

Sex differences in adolescent white matter architecture

BACKGROUND

Sex-specific trajectories in white matter development during adolescence may help explain cognitive and behavioral divergences between males and females. Knowledge of sex differences in typically developing adolescents can provide a basis for interpreting sexual dimorphisms in abilities and actions.

METHOD

We examined 58 healthy adolescents (12-14years of age) with diffusion tensor imaging (DTI). Diffusion parameters fractional anisotropy (FA), and mean (MD), radial (RD), and axial diffusivities (AD) were subjected to whole-brain voxel-wise group comparisons using tract-based spatial statistics. Sex differences in white matter microstructure were examined in relation to pubertal development.

RESULTS

Early adolescent females (n=29) evidenced higher FA in the right superior corona radiata, higher FA and AD in bilateral corticospinal tracts (≥164μl, p<.01), and lower MD in the right inferior longitudinal fasciculus (ILF) and left forceps major (≥164μl, p<.01) than age-matched males (n=29). Males did not show any areas of higher FA or lower MD than females, but had higher AD in the right superior longitudinal fasciculus, ILF, and forceps minor (≥ 164μl, p<.01). Pubertal stage did not account for sex disparities.

CONCLUSION

In early adolescence, females' motor tracts may reflect widespread changes, while males may undergo relatively more microstructural change in projection and association fibers.

HIV risk behavior in treatment-seeking opioid-dependent youth: results from a NIDA clinical trials network multisite study

OBJECTIVE

To assess baseline rates of and changes in HIV drug and sexual risk behavior as a function of gender and treatment in opioid-dependent youth.

METHODS

One hundred fifty participants were randomly assigned to extended buprenorphine/naloxone therapy (BUP) for 12 weeks or detoxification for 2 weeks; all received drug counseling for 12 weeks. HIV risk was assessed at baseline and 4-week, 8-week, and 12-week follow-ups. Behavioral change was examined using generalized estimating equations.

RESULTS

Baseline rates of past-month HIV risk for females/males were 51%/45% for injection drug use (IDU) (ns), 77%/35% for injection risk (P < 0.001), 82%/74% for sexual activity (ns), 14%/24% for multiple partners (ns), and 68%/65% for unprotected intercourse (ns). IDU decreased over time (P < 0.001), with greater decreases in BUP versus detoxification (P < 0.001) and females versus males in BUP (P < 0.05). Injection risk did not change for persistent injectors. Sexual activity decreased in both genders and conditions (P < 0.01), but sexual risk did not.

CONCLUSIONS

Overall, IDU and sexual activity decreased markedly, particularly in BUP patients and females, but injection and sexual risk behaviors persisted. Although extended BUP seems to have favorable effects on HIV risk behavior in opioid-dependent youth, risk reduction counseling may be necessary to extend its benefits.

Selective alterations within executive functions in adolescents with excess weight

Increasing evidence underscores overlapping neurobiological pathways to addiction and obesity. In both conditions, reward processing of preferred stimuli is enhanced, whereas the executive control system that would normally regulate reward-driven responses is altered. This abnormal interaction can be greater in adolescence, a period characterized by relative immaturity of executive control systems coupled with the relative maturity of reward processing systems. The aim of this study is to explore neuropsychological performance of adolescents with excess weight (n = 27, BMI range 24-51 kg/m(2)) vs. normal-weight adolescents (n = 34, BMI range 17-24 kg/m(2)) on a comprehensive battery of executive functioning tests, including measures of working memory (letter-number sequencing), reasoning (similarities), planning (zoo map), response inhibition (five-digit test (FDT)-interference and Stroop), flexibility (FDT-switching and trail-making test (TMT)), self-regulation (revised-strategy application test (R-SAT)), and decision-making (Iowa gambling task (IGT)). We also aimed to explore personality traits of impulsivity and sensitivity to reward. Independent sample t- and Z Kolmogorov-Smirnov tests showed significant differences between groups on indexes of inhibition, flexibility, and decision-making (excess-weight participants performed poorer than controls), but not on tests of working memory, planning, and reasoning, nor on personality measures. Moreover, regression models showed a significant association between BMI and flexibility performance. These results are indicative of selective alterations of particular components of executive functions in overweight adolescents.

Sex Differences in Self-Reported Risk-Taking Propensity on the Evaluation of Risks Scale

The Evaluation of Risks scale was recently developed as a self-report inventory for assessing risk-taking propensity, but further validation is necessary because most studies have predominantly included male subjects. Because males commonly exhibit greater risk-taking propensity than females, evidence of such a sex difference on the scale would further support its construct validity. 29 men and 25 women equated for age (range: 18 to 36 years) completed the scale. Internal consistency of the scale was generally modest, particularly among women. Men scored significantly higher than women on four of nine indices of risk-taking propensity, including Danger Seeking, Energy, Invincibility, and Total Risk-Propensity. Factors measuring thrill seeking and danger seeking correlated positively with a concurrent measure of sensation seeking. Although the higher scores exhibited by men are consistent with prior research on other measures of risk-taking, further research on this scale with samples including women is warranted.

Neuroimaging of the developing brain: taking "developing" seriously

With a few notable exceptions, many studies, be they behavioral, neuroimaging, or genetic, are snapshots that compare one child group to one adult group, which capture only two points in time and tell the scientist nothing about the mechanisms underlying neural trajectories over developmental time. Thus, a distinction needs to be drawn between child neuroimaging and developmental neuroimaging, the latter approach being relevant not just to children, but to adults and the ageing brain.

Changes in sensation seeking and risk-taking propensity predict increases in alcohol use among early adolescents

BACKGROUND

Conceptual models implicating disinhibitory traits often are applied to understanding emergent alcohol use, but, little is known of how inter-individual changes in these constructs relate to increases in alcohol use in early adolescence. The current study utilized behavioral and self-report instruments to capture the disinhibitory-based constructs of sensation seeking and risk-taking propensity to examine if increases in these constructs over time related to increases in early adolescent alcohol use.

METHODS

Participants included a community sample of 257 early adolescents (aged 9 to 12) who completed a self-report measure of sensation seeking, a behavioral task assessing risk-taking propensity, and a self-report of past year alcohol use, at 3 annual assessment waves.

RESULTS

Both sensation seeking and risk-taking propensity demonstrated significant increases over time, with additional evidence that change in the behavioral measure of risk-taking propensity was not because of practice effects. Greater sensation seeking and greater risk-taking propensity demonstrated concurrent relationships with past year alcohol use at each assessment wave. Prospective analyses indicated that after accounting for initial levels of alcohol use, sensation seeking, and risk-taking propensity at the first assessment wave, larger increases in both constructs predicted greater odds of alcohol use at subsequent assessment waves.

CONCLUSIONS

Results indicate the role of individual changes in disinhibitory traits in initial alcohol use in early adolescents. Specifically, findings suggest it is not simply initial levels of sensation seeking and risk-taking propensity that contribute to subsequent alcohol use but in particular increases in each of these constructs that predict greater odds of use. Future work should continue to assess the development of sensation seeking and risk-taking propensity in early adolescence and target these constructs in interventions as a potential means to reduce adolescent alcohol use.

Adolescents' heightened risk-seeking in a probabilistic gambling task

This study investigated adolescent males’ decision-making under risk, and the emotional response to decision outcomes, using a probabilistic gambling task designed to evoke counterfactually mediated emotions (relief and regret). Participants were 20 adolescents (aged 9–11), 26 young adolescents (aged 12–15), 20 mid-adolescents (aged 15–18) and 17 adults (aged 25–35). All were male. The ability to maximize expected value improved with age. However, there was an inverted U-shaped developmental pattern for risk-seeking. The age at which risk-taking was highest was 14.38 years. Although emotion ratings overall did not differ across age, there was an increase between childhood and young adolescence in the strength of counterfactually mediated emotions (relief and regret) reported after receiving feedback about the gamble outcome. We suggest that continuing development of the emotional response to outcomes may be a factor contributing to adolescents’ risky behaviour.

Adolescent risky decision-making: neurocognitive development of reward and control regions

Recent models hypothesize that adolescents' risky behavior is the consequence of increased sensitivity to rewards in the ventral medial (VM) prefrontal cortex (PFC) and the ventral striatum (VS), paired with immature cognitive control abilities due to slow maturation of the dorsal anterior cingulate cortex (ACC) and lateral PFC. We tested this hypothesis with fMRI using a gambling task in which participants chose between Low-Risk gambles with a high probability of obtaining a small reward (1 Euro) and High-Risk gambles with a smaller probability of obtaining a higher reward (2, 4, 6, or 8 Euro). We examined neural responses during choice selection and outcome processing in participants from 4 age groups (pre-pubertal children, early adolescents, older adolescents and young adults). High-Risk choices increased with rewards for all ages, but risk-taking decreased with age for low reward gambles. The fMRI results confirmed that High-Risk choices were associated with activation in VMPFC, whereas Low-Risk choices were associated with activation in lateral PFC. Activation in dorsal ACC showed a linear decrease with age, whereas activation in VMPFC and VS showed an inverted U-shaped developmental pattern, with a peak in adolescence. In addition, behavioral differences in risk-taking propensity modulated brain activation in all age groups. These findings support the hypothesis that risky behavior in adolescence is associated with an imbalance caused by different developmental trajectories of reward and regulatory brain circuitry.

Neuromaturation and Adolescent Risk Taking: Why Development Is Not Determinism

In the January 2009 issue of this journal, Males argues that adolescent brain science perpetuates the “myth of adolescent risk taking.” He contends that those who study adolescent neuromaturation are biological determinists who ignore the profound social and environmental forces that influence adolescent behavior to further their own agendas. Males mischaracterizes developmental research and misinterprets public health data. This article analyzes his argument and provides a response based on the evidence. There is significant cross-species evidence that adolescence serves an important developmental function on the road to full maturation and is not merely an oppressive social construction. Research on neuromaturation can help elucidate both the vulnerabilities and tremendous potential of the adolescent brain. It also provides the opportunity to examine the role of social environments in shaping developmental processes and to explore how reasoned understandings of adolescent brain and biological development are being used to inform interventions that scaffold adolescent vulnerabilities.

Glycaemic risk assessment in children and young people with Type 1 diabetes mellitus

AIM

To ascertain if those with diabetes (and their carers) ascribe a similar level of risk to blood glucose control as healthcare professionals.

METHODS

We used a structured questionnaire to ask fifty healthcare professionals how 'dangerous' a given blood glucose value was. Their answers were modelled to produce an algorithm of assessed risk. To examine if patients (and their carers) would apportion a similar level of risk to that of healthcare professionals, the same questionnaire was issued to fifty children and adolescents with Type 1 diabetes. For patients under 8 years old the carers completed the questionnaires (n = 23). Both patient and carers together completed the questionnaire for those aged 8-11 years (n = 15) and patients over the age of 11 years completed the questionnaire themselves (n = 12). The median results and interquartile range of the assessed level of risk, as determined by the two groups, were compared using a generalized linear model.

RESULTS

A significant difference (P < 0.0001) was identified between the median risk assessments of the two groups. The zero level of assessed risk was upward shifted in the patient group by 0.8 mmol/l and indicated the patients' view of risk increased.

CONCLUSIONS

Patients with Type 1 diabetes (and their carers) evaluate the risk from blood glucose values differently from healthcare professionals. The euglycaemic state (zero ascribed risk) that patients chose was 0.8 mmol/l greater than that of healthcare professionals, indicating, perhaps, hypoglycaemia avoidance, a more pragmatic approach or less exposure to current trends in glycaemic control.