Journal Digest: Methylphenidate and Driving, Frisson and Anhedonia, Bullying in the Metaverse, and More

A study in the Journal of Psychopharmacology suggests that methylphenidate may improve driving performance, especially in the latter half of drives lasting 40 minutes or more.

In the study, conducted by researchers at Swinburne University of Technology in Melbourne, 25 adults completed two experimental sessions on a driving simulator. Each road on the simulator replicated a 65-mile, bidirectional, four-lane highway in Australia, and participants were instructed to maintain a steady position in the left lane at a speed of about 62 miles per hour for 40 minutes. Participants each received a 10 mg dose of methylphenidate and a matching placebo capsule and took one of the capsules, randomly, 85 minutes before each session.

The researchers recorded measurements of driving performance such as deviations from the center of the lane and variations in speed and steering. They also measured the participants’ gaze, including how often their eyes remained still on a specific point or moved to focus on numerous points.

Compared with taking placebo, taking methylphenidate significantly decreased weaving and variations in speed while the participants were driving in the simulator, with the effects most pronounced between 20 and 40 minutes of driving. Taking methylphenidate also reduced how long participants’ eyes fixated on any given point, which may indicate more efficient visual information processing. However, taking methylphenidate did not significantly affect other aspects of the participants’ gaze, such as how structured or random their scanning patterns were.

In addition, participants reported an increase in sleepiness when taking placebo, but not when taking methylphenidate. “This absence of increased sleepiness coupled with improved performance suggests that methylphenidate may protect against typical performance decrements associated with prolonged task engagement and driving time,” the researchers wrote.

Aesthetic chills—the pleasant “shivers” people may feel in response to music, film, poetry, speeches, or beauty in nature or art—may help improve reward learning in people with depression symptoms and anhedonia, a study in the Journal of Affective Disorders has found.

Researchers at the Massachusetts Institute of Technology and colleagues analyzed data from 59 adults with current depressive symptoms, among whom 26 had elevated anhedonia and 33 had low anhedonia.

Participants completed three blocks of a probabilistic reward tasks for a total duration of 15 minutes to assess their reward learning. During this task, participants watched pictures of different animals on a screen and received a reward for identifying which species had the most animals in each photo, with one species more likely to provide a richer reward than the others. Participants were then randomly assigned to watch one of two videos known to elicit chills in the U.S. population: a commercial about kindness and a musical performance.

After exposure to the videos, participants rated their positive emotions; frequency, duration, and intensity of their chills; and frequency and intensity of goosebumps. Finally, they completed another three blocks of the probabilistic reward task.

During the second set of tasks, participants with elevated anhedonia who experienced chills showed significant improvements in their reward bias—i.e., they were more likely to pick the species offering rich rewards even if it was not correct—compared with those who did not experience chills.

“Exposure to chills resulted in an increase in reward learning from pre-exposure to post-exposure, indicating a temporary mitigation of blunted reward learning in these populations,” the researchers wrote. “These results highlight the potential of aesthetic chills as a novel approach to elicit and enhance positive affect in depressed populations.”

The Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND diet), which combines elements from the Mediterranean diet and the Dietary Approaches to Stop Hypertension (DASH) diet, is thought to slow cognitive decline, but most of the data come from predominantly White populations. Now a study in Alzheimer’s and Dementia finds that the MIND diet may slow cognitive decline in older Black adults as well, but only among those who adhere to it closely.

Researchers at Rush University Medical Center analyzed data from 5,259 adults (62% Black, 38% White) with a mean age of 73 years who completed food-frequency questionnaires and two or more cognitive assessments over an average of 7.8 years. The researchers calculated the participants’ MIND diet score based on their consumption of 10 healthy food groups (green leafy vegetables, other vegetables, nuts, berries, beans, whole grains, seafood, poultry, olive oil, and wine) and five unhealthy food groups (red meats, butter and stick margarine, cheese, pastries and sweets, and fried/fast food). They then grouped the participants into tertiles according to score.

The researchers found that a higher MIND diet score was associated with slower cognitive decline after adjusting for demographics and total calories. Among White participants, those in the middle and top tertiles had a lower risk of cognitive decline than those in the bottom tertile, but this association was only found in women. Among Black participants, only those in the highest tertile had a lower risk of cognitive decline than those in the lowest tertile, regardless of sex.

“We speculate that various established lifestyle and vascular risk factors among underrepresented populations may play a critical role in understanding the relationship of diet with cognition among diverse populations,” the researchers wrote.

Patients who engage in illicit substance use while admitted to the hospital, also known as non-prescribed substance use (NPSU), are more likely to discharge themselves before medical advice, according to a study in the Journal of the Academy of Consultation-Liaison Psychiatry.

Researchers at Vanderbilt University examined electronic health record data for 3,100 hospital encounters for which an addiction consult was documented between November 2018 and April 2022. Identifying 61 cases of NPSU, they compared the clinical characteristics, resource use, and treatment outcomes of these patients with those of patients who had a diagnosis of opioid use disorder (OUD) or stimulant use disorder but were not thought to have NPSU.

The researchers found that 31.1% of patients in the NPSU group discharged themselves before medical advice, compared with 11.7% of those with OUD or stimulant use disorder. In addition, patients with NPSU were more likely to have a medical hold order placed to prevent hospital discharge because of concerns for acute safety or capacity, to have both virtual and in-person one-to-one observer orders placed, and to stop taking medications for OUD before discharge.

“These findings suggest that individuals with NPSU may represent a subset of patients with [substance use disorder] with specific risk factors and needs benefitting from a unique set of interventions,” the researchers wrote. “Future studies should test mitigation strategies to reduce risk for NPSU before it occurs as well as reduce downstream consequences following NPSU. A consensus best practice for NPSU as a result of these efforts may allow the general medical setting to better capitalize on this ‘reachable moment’ in [substance use disorder] care.”

A large minority of youth who use virtual reality devices have experienced mistreatment such as hate speech, bullying, and harassment, a study in New Media & Society has found.

In the spring of 2023, researchers at Florida Atlantic University and the University of Wisconsin–Eau Claire conducted a survey of 5,005 youth ages 13 to 17 years. Overall, 32.6% of the participants reported that they owned virtual reality headsets and had visited a virtual reality platform in the previous year. Among these participants:

Boys and girls experienced similar rates of mistreatment overall, although girls experienced sexual harassment and grooming/predatory behavior more frequently than boys.

Both boys and girls reported feeling comfortable leaving metaverse rooms or channels in response to mistreatment, with girls significantly more likely than boys to use in-platform safety measures. However, neither boys nor girls used these safety measures often.

“Security- and privacy-preserving solutions offered to users in these environments are highly beneficial to help youth grow in resiliency and self-regulate online risk experiences … but clearly require further and better efforts to promote their adoption,” the researchers wrote.

A strong urge to be physically active may hinder efforts to regain weight in early treatment for anorexia nervosa, according to a study in the International Journal of Eating Disorders.

Researchers at Ruhr-University Bochum in Germany analyzed data from 53 adults with anorexia during the initial two weeks of inpatient treatment at a specialty eating disorder facility in Germany between November 2021 and October 2022. At the beginning of treatment, patients completed the 21-item State Urge to be Physically Active-Questionnaire (SUPA-Q), which measures a patient’s immediate urge to engage in any physical activity. Patients were weighed daily in the first weeks of treatment and at least once per week before being discharged. Researchers then reviewed the patients’ weight regain during treatment and compared it with their SUPA-Q scores.

Higher scores on the SUPA-Q were associated with lower initial weight gain and lower weight at discharge. Every one-point increase in the SUPA-Q was associated with a difference of 184 g (~6.5 oz) of weight regain per week.

According to the researchers, one plausible interpretation of their findings is that the urge to be active increases the levels of both exercising and non-exercising behaviors (e.g., fidgeting), leading to increased energy expenditure and thus lower weight regain. Guided exercises to minimize caloric expenditure or virtual reality programs that simulate movement might be useful interventions to counter this, they added. ■

“Activity urges could also result from neuroendocrine changes due to underfeeding … and thus mark the overall severity or duration of [anorexia nervosa] pathology, they wrote”