AimTo examine the association of body mass index (BMI) [kg/m2] and its classifications (underweight [BMI < 18.5], normal [18.5 ≤ BMI < 25], overweight [25 ≤ BMI < 30], and obese [BMI ≥ 30]) with brain structure in individuals with a wide range of BMI group.Materials and methodsThe participants included 382 right-handed individuals (mean age: 46.9 ± 14.3 years, 142 men and 240 women). The intelligence quotient was assessed using the Japanese Adult Reading Test. Voxel-based morphometry (VBM) and diffusion tensor (...) imaging (DTI) were performed to analyze the association of BMI and its classifications with gray and white matter structures, respectively.ResultsAccording to VBM, BMI was significantly and negatively correlated with the bilateral cerebellum exterior volumes. In group comparisons, the right cerebellum exterior volume was significantly lower in the overweight or obese group than in the underweight or normal group, while the bilateral cuneus and calcarine cortex, left cuneus, and left precuneus volume was significantly lower in the underweight group than in the non-underweight group. Sex-related stratification analyses for VBM revealed that BMI was significantly and negatively correlated with the bilateral cerebellum exterior volumes only in women. In group comparisons, the left cerebellum exterior volume was significantly lower in obese women than in non-obese women. The left thalamus proper and the right cerebellum exterior volumes were significantly lower in overweight or obese group than in underweight or normal group in men and women, respectively. The bilateral cuneus and calcarine cortex, left cuneus and carcarine cortex, and bilateral cuneus volume was significantly lower in underweight men than in non-underweight men. In contrast, there were no notable findings on DTI.ConclusionOur results suggest association of continuous BMI, being overweight or obese, and being underweight with decreased gray matter volume in individuals with a wide range of BMI group. Furthermore, sex-related differences are seen in the association of BMI and its classifications with regional gray matter volume reductions. Abnormally high or low BMIs may have a negative influence on regional gray matter volumes. (shrink)

Objectives To understand the ethical principles guiding college students’ abstention from pharmacological cognitive enhancement, and to determine the correlates associated with endorsing different principles. Design One-stage cluster sampling was used to implement a paper-based survey among undergraduate students attending one university in the U.S. Thematic analysis was used to explore the ethical principles guiding PCE abstention. Multivariate logistic regression analyses were used to examine sociodemographic correlates associated with endorsed ethical principles. Participants Of the 499 eligible students who completed the survey, (...) 259 students had a negative attitude towards PCE, did not engage in PCE, and provided reasons for abstention. Results The thematic analysis resulted in the identification of eight themes, with respondents often endorsing more than one theme per response. The three themes most endorsed were non-malfeasance, disapproval of drugs and dosage beneficence. The sociodemographic correlates associated with endorsing each theme varied across themes. Conclusions Students abstain from PCE for a multitude of reasons, many of which are guided by ethical principles. These findings may be incorporated into future prevention programming messages. (shrink)

ObjectivesTo understand the ethical principles guiding college students’ abstention from pharmacological cognitive enhancement, and to determine the correlates associated with endorsing different principles.DesignOne-stage cluster sampling was used to implement a paper-based survey among undergraduate students attending one university in the U.S. Thematic analysis was used to explore the ethical principles guiding PCE abstention. Multivariate logistic regression analyses were used to examine sociodemographic correlates associated with endorsed ethical principles.ParticipantsOf the 499 eligible students who completed the survey, 259 students had a negative (...) attitude towards PCE, did not engage in PCE, and provided reasons for abstention.ResultsThe thematic analysis resulted in the identification of eight themes, with respondents often endorsing more than one theme per response. The three themes most endorsed were non-malfeasance, disapproval of drugs and dosage beneficence. The sociodemographic correlates associated with endorsing each theme varied across themes.ConclusionsStudents abstain from PCE for a multitude of reasons, many of which are guided by ethical principles. These findings may be incorporated into future prevention programming messages. (shrink)