Higher Levels Of Sensation Seeking Research Articles

Sensation Seeking and Impulsivity Among Young Adults: Predictors of Risky Behavior

Abstract: This study examines the relationship between sensation seeking, impulsivity, and engagement in risky behaviors among young adults. 220 individuals, aged 18 to 25, filled out self-report questionnaires measuring their , sensation seeking (Brief Sensation Seeking Scale), impulsivity (Barratt Impulsiveness Scale), and risky behavior engagement (Risk Taking Questionnaire). Correlation analysis and Regression were used to examine the predictive power of impulsivity and sensation seeking for engaging in risky behavior. Mann Whitney U Test was conducted to check the gender differences in sensation seeking and impulsivity. The results show strong positive associations between sensation seeking, impulsivity, and engaging in risky behaviors. Among young adults, sensation seeking and impulsivity are important predictors of engaging in risky behavior. indicating that a higher levels of sensation seeking and impulsivity is associated with a greater chance of young people engaging in risky behaviors. In contrast to females, males were more inclined to seek out sensations. Impulsivity, however, didn't show any apparent gender differences among Young Adults. These findings highlight the importance of understanding how personality factors influence behavior and provide guidance for focused interventions meant to lower risky behaviors in this population.

Leisure Motivation and Sensation Seeking in Paintball

Within the scope of the research in which the sensation seeking behaviors and leisure motivation of individuals participating in paintball activities were determined, it was aimed to shed light on the relationship between the relevant measurement tools. In this context, Sensation Seeking Scale (SSS) and Leisure Motivation Scale (LMS) scales were utilized in addition to the personal information form. The data obtained from a total of 154 paintball activity participants were analyzed using descriptive statistics followed by independent sample t-test, one-way analysis of variance ANOVA and Pearson correlation tests. Post hoc tests were used for within-group comparisons. The findings show that the participants have high levels of sensation seeking and leisure motivation. On the other hand, it was determined that the sensation seeking and leisure motivation levels of the participants differed with the answers they gave to the questions about gender, age, education level, number of participation in paintball activity, frequency of playing paintball and how many years they have been interested in paintball. At the same time, a low level positive relationship was found between the total scores of the leisure motivation scale and the sensation seeking scale. As a result, it was concluded that participation in activities such as paintball, where the excitement element is at the forefront, has a direct relationship with leisure motivation, and from this point of view, by increasing motivation in leisure, various parameters such as sensation-seeking desire will increase in parallel with this.

Does sports participation affect the mediating role of impulsivity in the association between adverse childhood experiences and aggression?

Adverse childhood experiences (ACEs) and self-reported aggression have often been associated, however, the mediating and moderating mechanisms underlying this association are not fully understood. In addition, less is known about potential factors that could serve as protection against the development of aggressive behavior. In this study, we investigated a moderated mediation model of sports participation and five impulsivity traits including positive and negative urgency, sensation seeking, and lack of premeditation and perseverance, in the association between ACEs and two forms of aggression. The sample comprised 651 (68.5% females) individuals from a Dutch community ranging in age from 18 to 82 years (M = 34.08). Contrary to our expectations, sports participation did not affect the associations of ACEs, the five impulsivity traits, and reactive and proactive aggression, except the association between ACEs and lack of premeditation. Specifically, the detrimental effect of ACEs on the propensity to act without thinking, increases among individuals with lower levels of sports participation. In addition, it was also found that sports participation directly contributed to higher levels of sensation seeking. Finally, after controlling for sociodemographic variables, the positive association between ACEs and reactive aggression was significantly mediated by negative urgency, lack of perseverance, and lack of premeditation, while the positive association between ACEs and proactive aggression was significantly mediated by lack of premeditation and positive urgency. The findings of this study add to the body of knowledge about the role of sports participation and impulsivity traits in the development of both forms of aggression, however, replication studies among multiple populations are needed before firm conclusions can be drawn.

Longitudinal Examination of ENDS Use Among Young Adult College Students: Associations with Depressive Symptoms and Sensation Seeking.

The present study examined (1) intraindividual changes in the frequency of electronic nicotine delivery systems (ENDS) use across young adulthood, 18 to 30years old, and (2) if depressive symptoms and sensation-seeking tendencies, independently and in interaction with one another, were associated with these changes. Data were from a longitudinal study of students recruited from 24 Texas colleges and followed across six waves from fall 2015 to spring 2019. Participants (n = 1298; 36.3% non-Hispanic white, 56.3% women) were 18 to 26years old in fall 2015 and all reported past 30-day ENDS use on at least one wave. We used growth curve modeling for an accelerated longitudinal design to examine if ENDS use frequency changed with increasing age and if depressive symptoms and sensation seeking, independently and in interaction with one another, were associated with these changes. Results showed that ENDS use frequency increased with increasing age. Depressive symptoms and sensation seeking were not independently associated with more frequent ENDS use or an accelerated increase in ENDS use frequency across increasing age. However, a significant two-way interaction indicated that young adults with elevated depressive symptoms used ENDS more frequently, but only when they had higher levels of sensation seeking. Findings indicate that young adults with depressive symptoms are a heterogeneous population and that those with high levels of sensation-seeking tendencies are at elevated risk for more frequent ENDS use. Interventions for young adults high in both sensation-seeking and depressive symptoms may help prevent and decrease ENDS use.

Appetitive and aversive cue reactivities differentiate neural subtypes of alcohol drinkers

Craving reflects the subjective urge to use drugs and can be triggered by both positive and negative emotional states. No studies have systematically investigated the relative roles of these mechanisms in the pathophysiology of substance misuse. Here, we performed meta-analyses of drug cue-elicited reactivity and win and loss processing in the monetary incentive delay task to identify distinct neural correlates of appetitive and aversive responses to drug cues. We then characterized the appetitive and aversive cue responses in seventy-six alcohol drinkers performing a cue craving task during fMRI. Imaging data were processed according to published routines. The appetitive circuit involved medial cortical regions and the ventral striatum, and the aversive circuit involved the insula, caudate and mid-cingulate cortex. We observed a significant correlation of cue-elicited activity (β estimates) of the appetitive and aversive circuit. However, individuals varied in appetitive and aversive cue responses. From the regression of appetitive (y) vs. aversive (x) β, we identified participants in the top 1/3 each of those with positive and negative residuals as “approach” (n = 15) and “avoidance” (n = 11) and the others as the “mixed” (n = 50) subtype. In clinical characteristics, the avoidance subtype showed higher sensitivity to punishment and, in contrast, the approach subtype showed higher levels of sensation seeking and alcohol expectancy for social and physical pressure. The findings highlighted distinct neural underpinnings of appetitive and aversive components of cue-elicited reactivity and provided evidence for potential subtypes of alcohol drinkers.

Does Sensation Seeking Lead to Adolescents' Cyberbullying Perpetration? The Mediating Role of Moral Disengagement and The Moderating Role of Perceived Social Support.

Based on the general aggression model, the current study examined the mediating role of moral disengagement in the association between sensation seeking and cyberbullying perpetration and the moderating role of perceived social support. A total of 2,286 Chinese adolescents aged 11-16years completed the questionnaires regarding sensation seeking, cyberbullying perpetration, moral disengagement, and perceived social support. After gender and age were controlled, sensation seeking was significantly and positively associated with cyberbullying perpetration and this relationship was partially mediated by moral disengagement. Moderated mediation analysis further indicated that perceived social support moderated the relationship between sensation seeking and moral disengagement as well as sensation seeking and cyberbullying perpetration. These two relationships became weaker for adolescents with high perceived social support. Specifically, adolescents with higher levels of sensation seeking were more likely to develop moral disengagement and further engaged in cyberbullying perpetration, when they perceived less social support.

Positive and Negative Risk-Taking in Adolescence and Early Adulthood: A Citizen Science Study During the COVID-19 Pandemic.

Sensation seeking is an important underlying factor of both positive and negative forms of risk-taking during adolescence and early adulthood. However, macro-factors such as the global COVID-19 pandemic may influence sensation seeking opportunities and risk-taking behaviors that are considered negative and positive. Therefore, the primary aim of this study was to examine the associations between sensation seeking and behaviors that are considered positive or negative forms of risk-taking during the Covid-19 pandemic in a sample of adolescents and early adults (N = 660, Mage = 22.91, SD = 3.14). Using citizen science methods, negative risk-taking was defined as taking unaccepted risks, such as falsifying vaccination reports or deliberately contracting COVID-19. Positive risk-taking was defined as taking socially accepted risks, such as balancing between the risk to infect elderly people and the need to socialize with peers. Results showed that participants with higher levels of sensation seeking took more positive and negative COVID-19 related risks. An additional finding was that sensation seeking was positively associated with the need to contribute to society. This indicates that during adolescence and early adulthood, sensation seeking may be a driving factor for both positive (i.e., socially accepted) and negative (i.e., socially unaccepted) risk-taking in the context of a high-stake global pandemic, arguing against a one-direction negative relation between sensation seeking and risk-taking.

The psychology of kink: A survey study investigating stigma and psychological mechanisms in BDSM

IntroductionThe past years BDSM (an acronym for bondage and discipline, dominance and submission, and sadism and masochism) has gained a significant amount of attention and popularity in the general population, portraying an inaccurate image of BDSM and the people who share these interests. Yet despite this increasing popularity, only little empirical research has focused on this subject and it’s possible driving mechanisms so far, sustaining the existing misconceptions and stigma towards BDSM in general and BDSM practitioners in specific.ObjectivesWe aimed to gain more insights on understanding the underlying psychological mechanisms, such as sensation seeking and coping, in people who participate in BDSM-related activities, as well as into the factors which contribute to the existing stigma and discriminationMethodsIn a national survey study 256 Dutch-speaking BDSM-practitioners were compared to a matched sample of people from the general Belgian population (N = 300) who lack any interest in BDSM in two separate studies.ResultsAbout 86% of the general population maintained stigmatizing beliefs about these sexual interests and practices. In regard to sensation seeking and coping, compared to controls, BDSM practitioners reported signifcantly higher levels of sensation seeking for all dimensions, as well as the use of more active coping skills.ConclusionsPeople who do not conform to the current social standards of our society often seem to remain the subject of stigmatization and discrimination. Further research is needed to explore the psychological processes that drive BDSM interests in order to destigmatize and normalize consensual BDSM-related activities.DisclosureNo significant relationships.

The externalizing and internalizing pathways to marijuana use initiation: Examining the synergistic effects of impulsiveness and sensation seeking.

Adolescent marijuana use has become increasingly more problematic compared with the past; thus, understanding developmental processes that increase the liability of marijuana use is essential. Two developmental pathways to adolescent substance use have been proposed: an externalizing pathway that emphasizes the expression of aggressive and delinquent behavior, and an internalizing pathway that emphasizes the role of depressive symptoms and negative affect. In this study, we aimed to examine the synergistic role of impulsiveness and sensation seeking in the two risk pathways to determine whether both high and low levels of the traits are risk factors for marijuana use. Our study included 343 adolescents (52% were girls, 78% identified as Hispanic) that oversampled high-risk youth (78% had a family history of substance use disorder), assessed biannually between the ages of 13-16 years old. Moderated mediation analyses revealed that high levels of sensation seeking indirectly predicted marijuana use through higher mean levels of externalizing behavior. The positive relationship between sensation seeking and externalizing behavior was only significant at high levels of impulsiveness. Conversely, low levels of sensation seeking indirectly predicted marijuana use through higher mean levels of internalizing behavior. The negative relationship between sensation seeking and internalizing behavior was only significant at low levels of impulsiveness. Collectively, these results demonstrate that high and low levels of both impulsiveness and sensation seeking confer increased risk of marijuana use, albeit through different mechanisms. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Impact of the COVID-19 pandemic on travelers' preference for crowded versus non-crowded options.

Crowding is a critical determinant of consumers' satisfaction with and preferences for different shopping and travel situations. When considering a selection of travel and hospitality options, travelers are influenced by perceived crowding. This research examined how the current health crisis (i.e., the COVID-19 pandemic) affects travelers' preferences for crowded and non-crowded options. Specifically, we predicted that travelers would have a diminished preference for crowded (vs. non-crowded) travel and hospitality options when the ongoing pandemic is salient. We demonstrated that the primary effect of the salience of the threat was persistent across different travel categories and contexts. We also found that travelers with high levels of sensation seeking and a high need for uniqueness show the opposite pattern, suggesting a possible recovery strategy from the pandemic. Five experimental studies provide several theoretical and managerial implications for travel and hospitality business marketers.

On Imbalance of Impulse Control and Sensation Seeking and Adolescent Risk: An Intra-individual Developmental Test of the Dual Systems and Maturational Imbalance Models

Heterogeneity in development of imbalance between impulse control and sensation seeking has not been studied until now. The present study scrutinized this heterogeneity and the link between imbalance and adolescent risk. Seven-wave data of 7,558 youth (50.71% males; age range from 12/13 until 24/25) were used. Three developmental trajectories were identified. The first trajectory, “sensation seeking to balanced sensation seeking”, included participants with a higher level of sensation seeking than impulse control across all ages. The second trajectory, “moderate dominant control”, included participants showing moderate and increasing impulse control relative to sensation seeking across all ages. The third trajectory, “strong late dominant control”, included participants showing the highest level of impulse control which was about as strong as sensation seeking from early to middle adolescence and became substantially stronger from late adolescence to early adulthood. Although the systematic increase of impulse control in all subgroups is in line with both models, neither of these combined trajectories of control and sensation seeking was predicted by the Dual Systems Model or the Maturational Imbalance Model. Consistent with both models the “sensation seeking to balanced sensation seeking” trajectory showed the highest level of substance use. It can be concluded that, even though both theories adequately predict the link between imbalance and risk, neither the Dual Systems Model nor the Maturational Imbalance Model correctly predict the heterogeneity in development of imbalance between impulse control and sensation seeking.

Sensation seeking and nonsuicidal self-injurious behavior among adolescent psychiatric patients

The Benefits and Barriers model of NSSI postulates that engagement in NSSI is positively reinforced by potent benefits, however there are a host of barriers to engagement, any one of which is salient enough to prevent engagement. It is possible that individual differences in sensation seeking, a trait that describes optimal level of positive reinforcement, may alter the balance between the benefits and barriers of engagement in NSSI. There are significant associations between engagement in NSSI and sensation seeking in college undergraduates, a population with disproportionately high rates of NSSI. However, it is unclear whether these traits play a similar role in adolescents. We expected that higher levels of sensation seeking would positively relate to any NSSI history, lifetime frequency of NSSI, and earlier age at onset of NSSI among a sample of 200 adolescents in a psychiatric hospital. Consistent with previous research, results indicated that females were more likely to engage in NSSI than males. Additionally, increased sensation seeking was associated with greater likelihood of ever engaging in NSSI and a greater number of different NSSI methods tried. Though we expected sensation seeking would be significantly related to lifetime NSSI frequency and earlier onset of NSSI, it was not. Findings suggest that individual differences may alter relations between the benefits and barriers of NSSI and that measuring sensation seeking in adolescents, especially females, and especially those experiencing psychological distress, may identify those at highest risk for engaging in NSSI and may allow for targeted intervention with these individuals.

The Development of Impulsivity and Sensation Seeking: Associations with Substance Use among At-Risk Adolescents.

We investigated if the dual systems model could explain the increased rates of substance use among at-risk youth. This study sampled 365 adolescents, 289 of which had a family history of substance use disorder, assessed biannually between the ages 13-16years old. Growth curve analyses revealed that higher levels of impulsivity were related to higher levels of sensation seeking and a slower rate of decline in impulsivity was related to a faster rate of increase in sensation seeking. Only family history status and sensation seeking were directly associated with substance use (marijuana, alcohol) at age 16, though family history status was also indirectly related to substance use through higher levels of impulsivity to higher levels of sensation seeking.

The Psychology of Kink: A Cross-Sectional Survey Study Investigating the Roles of Sensation Seeking and Coping Style in BDSM-Related Interests.

Despite the gaining popularity in mainstream media of the phenomenon that is BDSM, empirical research on the motives and underlying psychological mechanisms driving BDSM practitioners is scarce. The current study focused on the potential driving roles of sensation seeking and coping styles in BDSM-related interests and behavior. A cross-sectional survey questionnaire was completed by 256 Dutch-speaking BDSM practitioners (110 men, 135 women, 7 gender fluid, 2 genderless, 1 other not specified), 1 missing (this participant did not answer the question regarding gender, but did answer all other survey items) and a matched control group lacking any BDSM interest recruited from the general Belgian population (N = 300; 135 men, 158 women, 4 gender fluid, 3 genderless). The questionnaire consisted of several items surveying different BDSM identities and interest levels of BDSM-related activities, an adapted version of the Dutch Sensation Seeking Scale, and items querying seven coping styles. Compared to controls, BDSM practitioners reported significantly higher levels of sensation seeking for all dimensions (experience seeking, thrill seeking, and distraction seeking), as well as the use of more active coping skills such as problem solving and taking action. Gender differentiated which specific coping skills were being used with women seeking out more emotional support and comfort and reaching out more for help and advice in both the BDSM and control group, and men taking more action and seeking distraction in leisure. About 40% of the practitioners reported using BDSM itself as a coping strategy. Further research is needed to explore the link between coping and sexuality in general, and to other psychological processes that drive BDSM interests in order to destigmatize and normalize consensual BDSM-related activities within the general population.

Immigrant status and problem-gambling severity in adolescents: Evidence for moderation by sensation seeking

Despite the multidimensional/ecological integrative perspective that suggests that the risk for problem gambling in adolescents can be determined by an interactive effect of different risk factors, few studies have investigated how different individual factors may affect the risk for problem gambling in a multiplicative way. This study aimed at exploring the interaction between immigrant status (IS) and sensation seeking (SS) on adolescent problem-gambling severity. The study involved 994 Italian adolescents (64% boys, Mage = 16.57, SD = 1.62). Participants’ IS, SS and problem-gambling severity were individually assessed through, respectively, a socio-demographic questionnaire, the Brief Sensation Seeking Scale (BSSS) and the South Oaks Gambling Screen – Revised for Adolescents (SOGS-RA). Results showed that, among immigrant adolescents, there were higher levels of problem-gambling severity and a higher distribution of at-risk and problem gamblers with respect to non-immigrant adolescents. Both IS and SS had significant direct effects on problem-gambling severity, with IS and higher levels of SS being predictors of greater severity. A moderation analysis – controlling for gender and age – showed that adolescents with high scores of SS were more prone to experience gambling problems if they were also immigrant. These results have important implications for practice as they emphasize that specific interventions aimed at preventing problem gambling would be required for adolescents from immigrant families. In particular, it would be important to consider the role of SS in this specific youth target.

Sensory processing in toddlers with autism spectrum disorders

ABSTRACT Sensory symptoms are common in individuals with autism spectrum disorders (ASD) but the patterns of these symptoms vary. Early assessment of sensory processing is therefore crucial for diagnosis and early intervention. However, studies in this area are conducted almost exclusively in English-speaking populations. In our study, we examined sensory processing in 380 toddlers: 96 with ASD, 42 with other developmental disabilities (DD), and 242 typically developing (TD) controls. Caregivers completed a Polish version of the Infant/Toddler Sensory Profile (ITSP). Results showed that children with ASD and those with DD were more hypo- and hypersensitive and showed more avoidance of stimulation than TD controls. Children with DD had less severe symptoms than those with ASD and showed higher levels of sensation seeking than the ASD and TD groups. Furthermore, we identified four sensory subtypes with different sensory thresholds and regulatory strategies. Two of them reflected healthy patterns of sensory processing: a healthy-active and a healthy-passive subtype. The third subtype was characterized by mild sensory symptoms. The fourth pattern was specific to toddlers with ASD and included severe sensory symptoms and avoidance of stimulation. The Polish ITSP may be a useful instrument in early diagnosis of ASD, as well as in future research.

The effect of psychosocial factors on perceptions of driver education using the goals for driver education framework

Professional driver education and training has often been found in evaluations to not provide additional safety benefits for young drivers. However, it is possible that identifying how psychosocial factors affect perceptions of driver education may contribute to improve program design, content and implementation. The Goals for Driver Education (GDE) framework was used in this research to explore the impact of various psychosocial factors, such as sensation seeking, normlessness, attitudes towards driver risk taking and positive attitudes towards speeding on the perceptions of young drivers participating in a professional driver education courses. One hundred and fourteen young drivers (Mage = 17.89, SD = 0.85) who had attended a driver education course within the past three years completed an online survey that collected socio-demographic information, perceptions of the benefits of education for individuals learning to drive at each level of the GDE framework, and information about psychosocial factors. Overall, the results suggested that psychosocial factors do affect young driver perceptions of driver education and training. Higher levels of sensation seeking predicted that participants thought it beneficial for novice driver education to focus on vehicle manoeuvring (Level 1), mastery of traffic situations (Level 2) and goals and contexts for driving (Level 3) but not the highest level of the GDE matrix, goals for life. Higher levels of normlessness predicted participants believing it was more beneficial for new drivers to learn about the goals and contexts for driving. This suggests there is a need for driver educators to consider personalising their programs as much as possible to take into account the psychosocial differences between individuals, which may impact on the way they respond to the education they receive.

Sensation seeking and psychoactive substance consumption: differences between a consumer and a non-consumer sample

Introduction. Internationally, there have been several studies carried out in order to demonstrate the relationship between a high level of Sensation Seeking and illegal drug abuse. However, few studies in Colombia replicate those results. The objective is to examine the difference of Sensation Seeking personality trait and its subscales in the behaviour of drug abuse on two Colombian samples, consumers and non-consumers, measured through the Sensation Seeking Scale-V (Zuckerman & Kulhman, 1980). Methodology. 341 adult subjects, from both genders, composed the sample, half of them were consumers of illegal drugs and half of them non-consumers, assessed through Sensation Seeking Scale Version V. Results. There is a significant difference between consumers and non-consumers within the general scale and three subscales of the trait (Thrill and Adventure Seeking, Experience Seeking and Disinhibition). Discussion. Differences between the scores of consumers and non-consumers sample regarding the general trait and subtraits show the relevance of personality factors regarding substance abuse, independently than social and learning factors are influential as well. Conclusions. There is a link between Sensation Seeking and substance abuse showing the importance of the level of the trait in the multivariate phenomenon of substance dependence.

Simultaneous Use of Alcohol and Marijuana: Patterns and Individual Differences

Background: Simultaneous alcohol and marijuana (SAM) use, or using alcohol and marijuana in such a way that their effects overlap, is associated with negative health and behavioral outcomes. Objectives: Our study sought to fill gaps in our knowledge on this emerging public health concern by comparing SAM users and alcohol-only users on individual-level factors and substance use outcomes as well as examining associations of SAM use frequency, within users. Methods: Participants were recruited through online postings. Our analytic sample consisted of 1017 young adults (18–25 years) who reported past-month alcohol use. Most were male (67.8%), Caucasian (71.5%), and had attended at least some college (74.8%). Results: Past-year SAM users reported higher levels of sensation seeking and greater perceptions of their close friends’ drinking behavior in comparison to alcohol-only users. SAM users reported heavier and more frequent alcohol use than alcohol-only users. Within past-year SAM users, 70% reported SAM use at least weekly. More frequent SAM use was associated with all alcohol use outcomes (e.g., weekly quantity, frequency, alcohol-related problems) and marijuana use outcomes (e.g., quantity, frequency, peak use) and higher drinking norms. Conclusions/Importance: It is clear that SAM users are a vulnerable sub-population of young adult drinkers. SAM users are differentiated from alcohol-only users in terms of their personality characteristics and perceptions of peer groups’ drinking. SAM users and more frequent users are also at heightened risk for substance use outcomes. Prevention and intervention efforts targeting high-risk drinking may benefit from also assessing whether they simultaneously use alcohol and marijuana.

Sensation seeking in 3- to 6-year-old children: associations with socio-demographic parameters and behavioural difficulties

BackgroundThe present study investigates whether sensation seeking in pre-school-age children is associated with age, gender and socio-economic status, and how sensation seeking relates to behavioural difficulties.MethodsThe study sample consisted of 423 three- to six-year-old children whose parents had completed questionnaires on the children’s sensation seeking (Sensation Seeking Scale for Young Children), socio-economic status, and behavioural difficulties (Strengths and Difficulties Questionnaire). Multiple linear regression models were applied to investigate associations between sensation seeking and age, gender, socio-economic status and behavioural difficulties.ResultsSensation seeking was significantly higher in male vs. female children but not associated with children’s socio-economic status. Furthermore, sensation seeking was positively correlated with conduct problems, but negatively with emotional symptoms and peer-relationship problems.ConclusionThese results replicate findings in adults and strengthen the assumption that sensation seeking is a personality trait that is already observable in early childhood. Furthermore, our results suggest relationships between higher levels of sensation seeking and externalising behaviour as well as relationships between lower levels of sensation seeking and internalising behaviour.Trial registrationLIFE Child study: ClinicalTrials.gov, clinical trial number NCT02550236.