A longitudinal study in the Netherlands found that infants who displayed greater curiosity at 8 months of age tended to have higher IQ scores at 3.5 years of age. However, this association was present only in infants who displayed the highest levels of curiosity (one-third of the most curious children). The research was published in Developmental Science.

During infancy, cognitive abilities develop rapidly. Infants very swiftly acquire basic knowledge about the world and develop various skills, from the motor skills needed to move their bodies and walk to the language skills that allow them to communicate with their caregivers and other people.

However, infants show measurable differences in cognitive abilities. They differ in abilities such as information processing speed, attention control, and learning efficiency. Longitudinal research indicates that these early differences are modest but reliable predictors of later cognitive abilities. Early attention regulation and processing speed have been linked to later executive functions and general intelligence. Memory and learning capacities in infancy are associated with later language development and academic skills.

Nevertheless, environmental factors such as caregiver responsiveness, stimulation, nutrition, and socioeconomic conditions strongly shape developmental trajectories. Brain plasticity in early childhood allows later experiences to amplify, compensate for, or impede the development of early cognitive tendencies.

Study author Eline R. de Boer and her colleagues examined whether variations in infants’ curiosity predicted cognitive abilities in childhood. These authors hypothesized that infants’ curiosity is associated with their intelligence in childhood and that infants who are more curious—i.e., more sensitive to information—show higher intelligence 3 years later.

Study participants were 60 infants who were first enrolled in the study when they were 8 months old. The number of recruited infants was initially larger (90), but 30 were excluded or dropped out for various reasons. Fifty percent of them were girls. In 93% of cases, at least one of an infant’s caregivers had completed a form of higher education, and for 63% of the infants, both caregivers had higher education.

The study authors used a visual learning task to assess infants’ curiosity. In the task, a series of pictures were presented to the infant on a screen while the authors tracked where the infant looked. They combined the information about which pictures were displayed and where with information on where the infant was looking (and for how long) to derive an assessment of sensitivity to information for each infant. At 3.5 years of age, the children completed a standardized intelligence test: the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition—Nederlandse bewerking.

Results showed that infants who displayed greater sensitivity to information—i.e., who showed greater curiosity—when they were 8 months old tended to have higher intelligence scores at 3.5 years of age. Further analysis revealed that the link between curiosity in infancy and later intelligence is not linear; rather, the association is strongest in infants who displayed the highest levels of curiosity.

“We show that early-existing individual differences in curiosity-driven learning play an important role in cognitive development and allow predicting differences in cognitive capacity over a time span of almost 3 years, supporting the direction modern theories are taking in emphasizing the role of infant curiosity in early learning. Benefiting from this discovery, these results suggest that finding ways to stimulate curiosity might be a promising avenue for boosting exploratory behavior and supporting learning in early childhood,” the study authors concluded.

The study contributes to scientific knowledge about early indicators of cognitive ability. However, the association between curiosity and later intelligence was present only in the one-third of children identified as most curious. In children who showed average or below-average curiosity, curiosity was not associated with later intelligence.

The paper, “Individual Differences in Infants’ Curiosity Are Linked to Cognitive Capacity in Early Childhood,” was authored by Eline R. de Boer, Francesco Poli, Marlene Meyer, Rogier B. Mars, and Sabine Hunnius.

An analysis of data from the National Health and Nutrition Examination Survey (2009–2020) found that men with higher sunlight affinity tend to have fewer depressive symptoms. They also reported sleeping problems less often; however, their sleep durations tended to be shorter. The paper was published in PLOS ONE.

In the context of this study, “sunlight affinity” is a novel metric proposed by the authors to measure an individual’s tendency to seek and enjoy natural sunlight. It combines psychological factors (preference for sun) and behavioral factors (actual time spent outdoors). Generally, the drive for sunlight is influenced by biological factors such as circadian rhythms, melatonin suppression, and serotonin regulation.

People with high sunlight affinity tend to report improved mood, energy, and alertness during bright daytime conditions. This tendency is partly genetic but is also shaped by developmental experiences, climate, and cultural habits. Conversely, low sunlight affinity may be associated with discomfort in bright light or a preference for dim environments.

While sunlight affinity is conceptually related to light sensitivity and seasonal affective patterns, it is not a clinical diagnosis. In environmental psychology, it helps explain preferences for outdoor activities and sunlit living or working spaces. In health contexts, moderate sunlight affinity can promote behaviors that support vitamin D synthesis and circadian stability.

Lead author Haifeng Liu and his colleagues investigated the associations between sunlight affinity and symptoms of depression and sleep disorders in U.S. men. They examined two dimensions of sunlight affinity: sunlight preference (how often a person chooses to stay in the sun versus the shade) and sunlight exposure duration (how much time a person spends outdoors). They noted that while recent findings indicate light therapy might help reduce depressive symptoms and improve sleep, the impact of natural sunlight exposure remains underexplored.

The authors analyzed data from 7,306 men who participated in the National Health and Nutrition Examination Survey (NHANES) between 2009 and 2020. NHANES is a continuous, nationally representative U.S. program that combines interviews, physical examinations, and laboratory tests to assess the health, nutritional status, and disease prevalence of the civilian, noninstitutionalized population.

The researchers selected males aged 20–59 years who provided all the necessary data. These individuals completed assessments for sunlight affinity, depressive symptoms (using the Patient Health Questionnaire-9), sleep disorder symptoms (answering, “Have you ever told a doctor or other health professional that you have trouble sleeping?”), and sleep duration.

Sunlight affinity was assessed by asking participants, “When you go outside on a very sunny day for more than one hour, how often do you stay in the shade?” and by asking them to report the time they spent outdoors between 9:00 AM and 5:00 PM over the previous 30 days.

The results showed that participants with a higher preference for sunlight and longer exposure durations tended to have fewer depressive symptoms. They also reported sleep problems less often, though their total sleep time tended to be shorter.

“This study revealed that sunlight affinity was inversely associated with depression and trouble sleeping and positively associated with short sleep in males. Further longitudinal studies are needed to confirm causality,” the authors concluded.

The study sheds light on the links between sunlight affinity, depression, and sleep problems. However, it should be noted that the cross-sectional study design does not allow for causal inferences. Additionally, all study data were based on self-reports, leaving room for reporting bias to have affected the results.

The paper, “Associations of sunlight affinity with depression and sleep disorders in American males: Evidence from NHANES 2009–2020,” was authored by Haifeng Liu, Jia Yang, Tiejun Liu, and Weimin Zhao.

An analysis of the Survey of Health, Ageing, and Retirement in Europe data found that individuals born between 1945 and 1957 (baby boomers) who were in stable marriages experience greater well-being in old age compared to those who are single or in less stable relationships. Participants with lower education who have divorced showed even lower well-being. The study was published in the European Journal of Population.

Romantic couple relationships play a central role in adult life. A relationship with a romantic partner provides companionship, emotional security, and a sense of belonging. Through daily interactions, romantic partners influence each other’s emotions, behaviors, and life choices.

Supportive and stable relationships are associated with better mental health, including lower levels of depression, anxiety, and loneliness. They can also buffer the effects of stress by offering emotional reassurance and practical help during difficult periods.

High-quality romantic relationships are linked to better physical health, including lower risk of cardiovascular disease and improved immune functioning. Partners shape each other’s health behaviors, such as diet, physical activity, substance use, and adherence to medical advice. Conversely, conflictual or unsupportive relationships can increase stress, negatively affect mental health, and contribute to poorer physical outcomes.

Study author Miika Mäki and his colleagues note that well-being in old age reflects combined experiences over the entire life course. Previous studies indicate that marriage dissolutions have long-term negative implications on well-being and health that can persist even among those who remarry. Similarly, unstable partnerships and multiple relationship transitions or long-term singlehood are all associated with higher levels of depression and stress and lower social and emotional support.

To explore this in more detail, these authors conducted a study in which they examined the links between well-being in old age and romantic relationship history. They hypothesized that individuals with stable marital relationship histories will experience higher well-being after age 60 compared to those with less stable relationship histories.

To explore this, they analyzed data from the SHARELIFE interviews of the Survey of Health, Ageing, and Retirement in Europe (SHARE). SHARE covers households with at least one member over 50 years of age in all EU countries, Switzerland, and Israel. The SHARELIFE interviews were conducted in 2008 and 2017. Respondents were asked to report, among other things, on their childhood circumstances and their romantic relationships, including all cohabitational, marital, and dating relationships.

This analysis was based on the data of individuals born between 1945 and 1957, who were at least 60 years old in 2017 (all part of the baby boomer generation). Data from a total of 18,256 participants were included in the analyses.

Analyses identified 5 general patterns of partnership history: stable marriage (a brief period of dating followed by a permanent first marriage), being remarried (getting married in their 20s and divorcing within the first 10 years, only to remarry in their 30s, with later marriages often preceded by cohabitation), divorce (the same as the previous one, but without a remarriage), serial cohabitation (dating and cohabiting prominent throughout the life course), and single (individuals who never lived with a partner, and many of whom never dated).

Most of the participants were in the stable marriage category, while the singles and serial cohabitation patterns were the rarest. Men were more frequent in the single category, while women were more frequent in the divorce category.

Further analysis revealed that individuals in the stable marriage category enjoyed greater well-being compared to all the other categories. This difference was present across all education levels. However, those with lower education who have divorced experienced even lower well-being in old age. Overall, results indicate that those with fewer resources tend to suffer more from losing a partner.

Study authors conclude that “…life courses characterized by stable marriages tend to be coupled with good health and high quality of life, unstable and single histories less so. Low educational attainment together with partnership trajectories characterized by divorce have pronounced adverse well-being associations. Our results hint at family formation patterns that may foster well-being and mechanisms that potentially boost or buffer the outcomes.”

The study sheds light on the links between romantic relationship patterns and well-being in old age. However, it should be noted that the study exclusively included individuals from the baby boomer generation. Given pronounced cultural differences between generations in the past century, results on people from other generations might not be identical.

The paper, “Stable Marital Histories Predict Happiness and Health Across Educational Groups,” was authored by Miika Mäki, Anna Erika Hägglund, Anna Rotkirch, Sangita Kulathinal, and Mikko Myrskylä.

An 18-week experimental study examining the effects of topiramate on tobacco smoking and alcohol use found no differences between groups treated with topiramate and those receiving placebo treatment in the last 4 weeks of treatment. However, the authors report a lower average percentage of heavy drinking days and drinks per day in participants treated with the highest tested dose of the substance compared to the other groups across the assessments conducted after the target quit date. The research was published in Alcohol Clinical & Experimental Research.

Topiramate is a prescription medication originally developed as an antiepileptic drug to treat seizures. It is also commonly used for migraine prevention and, in combination with other drugs, for weight management.

Topiramate works by modulating multiple neurotransmitter systems, including enhancing the activity of the inhibitory neurotransmitter GABA and reducing the excitatory activity of the neurotransmitter glutamate. Because of these mechanisms, topiramate can reduce the heightened excitability of neurons in the brain.

The medication is sometimes used off-label for conditions such as bipolar disorder, alcohol use disorder, and binge eating disorder. However, it has substantial cognitive and neurological side effects (e.g., cognitive slowing, difficulty with word finding, tingling sensations in hands or feet), which limit its long-term use.

Study author Jason D. Robinson and his colleagues wanted to explore whether topiramate would be effective in treating individuals with alcohol use disorder and tobacco use disorder. More specifically, they wanted to see whether 250 mg and 125 mg of topiramate per day would result in reducing heavy drinking and cigarette smoking behaviors in individuals motivated to try to quit both substances. The study authors hypothesized that the higher dose would be more effective than the lower dose.

Study participants were 236 adults who met the criteria for both alcohol use disorder and tobacco use disorder. They were recruited from San Diego, Houston, and Charlottesville. Participating women had been drinking at least 8 standard drink units (of alcohol) per week in the past 30 days, while this minimum limit was 15 standard drink units for men.

One standard drink unit is the amount of alcohol that contains about 14 grams of pure ethanol, roughly equivalent to a small beer (350 ml), a glass of wine (150 ml), or a shot of spirits (45 ml). They were also smoking an average of 5 or more cigarettes per day in the 30 days before the study.

Study participants were randomly divided into three groups. One group was assigned to receive a high dose of topiramate, up to 250 mg/day; the second group would receive up to 125 mg/day of topiramate; and the third group would receive a placebo.

The placebo consisted of pills that looked like topiramate pills but contained no active ingredients. Participants did not know which treatment they were receiving, and the same was the case for the researchers directly working with them. In other words, the study was double-blind.

The treatment lasted for 18 weeks. During this period, participants took their assigned treatment and received adherence counseling, including a self-help manual for smoking cessation. In the first 5 weeks, the dose was gradually increased, and at the start of week 6, participants were expected to actively stop both alcohol drinking and tobacco smoking.

Results showed no differences between the study groups regarding the primary outcomes. In other words, the three groups did not differ significantly in the percentage of heavy drinking days and the rate of continuous smoking abstinence in the last 4 weeks of treatment.

However, study authors report that participants in the group that received 250 mg of topiramate had a lower average percentage of heavy drinking days and drinks per day compared to the other two groups when all assessments done from week 6 onward were taken into account. Similarly, participants in both topiramate groups smoked fewer cigarettes per day and reported greater cigarette abstinence than those in the placebo group during the same period.

“While the primary analyses did not find evidence that topiramate decreases drinking and smoking behavior, likely influenced by a high attrition rate and poor medication adherence, exploratory repeated measures analyses suggest that topiramate 250 mg reduces drinking behavior and that both the 125 mg and 250 mg doses reduce smoking behavior,” the study authors concluded.

The study contributes to the scientific understanding of the effects of topiramate. However, it should be noted that 236 participants started the treatments, but only 107 completed them, which is less than half. This extremely high attrition rate could have substantially altered the results.

The paper, “High- and low-dose topiramate for the treatment of persons with alcohol use disorder who smoke cigarettes: A randomized control trial,” was authored by Jason D. Robinson, Robert M. Anthenelli, Paul M. Cinciripini, Maher Karam-Hage, Yong Cui, George Kypriotakis, and Nassima Ait-Daoud Tiouririne.

A study conducted in Israel found that survivors of childhood maltreatment showed impaired belief updating when interacting with strangers. Moreover, in individuals with impaired belief updating, childhood maltreatment severity was associated with the severity of PTSD symptoms, while those with better updating showed low levels of PTSD symptoms regardless of the severity of childhood maltreatment they experienced. The research was published in Behaviour Research and Therapy.

Childhood maltreatment occurs when caregivers fail to provide safety, care, or emotional support, or actively cause harm to the child. Such experiences can disrupt normal emotional, cognitive, and social development. Childhood maltreatment is strongly associated with an increased risk for mental health disorders, including depression, anxiety disorders, post-traumatic stress disorder, and substance use disorders. It can also affect stress regulation systems, leading to long-term alterations in brain development and stress hormone functioning.

Individuals exposed to maltreatment often show difficulties with emotion regulation, self-esteem, and interpersonal relationships. Cognitive effects include problems with attention, memory, and executive functioning. Childhood maltreatment is also linked to a higher risk of physical health problems later in life, such as cardiovascular disease, metabolic disorders, and chronic inflammation. The impact of maltreatment varies depending on its type, severity, duration, and the presence of protective factors like supportive relationships.

Study author Shir Porat-Butman and her colleagues note that, among other issues, survivors of childhood maltreatment show greater interpersonal distance. The authors reason that this might be because of their inability to distinguish between friends and strangers, due to a rigid interpersonal style that fails to adapt flexibly to varying levels of relational closeness.

With this in mind, the researchers conducted a study aiming to test whether adults with a history of childhood maltreatment show alterations in learning new positive and negative information about friends and strangers. They also wanted to see whether childhood maltreatment was associated with difficulties in updating social beliefs about friends and strangers when confronted with inconsistent information.

Study participants were 114 individuals recruited from the general population. The authors note that the study was conducted during an ongoing war, meaning that all participants were exposed to additional trauma. Participants’ average age was 28 years**, and** 70% were female.

Participants completed assessments of childhood maltreatment (the Childhood Trauma Questionnaire), PTSD symptoms (the Posttraumatic Stress Disorder Checklist), social anxiety symptoms (the Mini Social Phobia Inventory), anxiety and depression symptoms (the Hospital Anxiety and Depression Scale), and cumulative traumatic exposure (the Cumulative Traumatic Exposure Questionnaire).

They also completed the Friend-Stranger Social Updating task. In this task, participants are shown pictures of faces labeled either “friends” or “strangers.” Participants have to decide whether to approach or avoid the person.

If they decide to approach, they can either gain or lose points. If they decide to avoid, they neither lose nor gain points. Half of the faces (of both “strangers” and “friends”) are associated with gaining points after approaching them, and approaching the other half of faces loses points.

Crucially, the task includes a second phase (the updating phase). After participants learn these associations, the outcomes are reversed without warning: faces previously associated with gains result in losses, and vice versa. Participants must realize this change and adjust their choices. In this way, the assessment tests participants’ capacity to update beliefs about other people when provided with new, contradictory information.

Results showed that, in general, participants were better at learning after receiving points than after losing them. They were also better at learning when pictures were labeled as “friends” than when they were labeled as “strangers.”

Childhood maltreatment experiences were not associated with the initial formation of beliefs (learning who to avoid or approach in the first phase). However, participants with more severe childhood maltreatment history tended to show impaired updating of beliefs when interacting with strangers. In other words, once the rules changed, they were less efficient in updating their beliefs about which of the “stranger” pictures were now safe or unsafe.

Moreover, this impaired updating of beliefs moderated the association between childhood maltreatment and PTSD symptom severity. In individuals with impaired updating of beliefs, more severe childhood maltreatment was associated with more severe PTSD symptoms. On the other hand, participants with flexible updating of beliefs reported low PTSD symptom levels regardless of childhood maltreatment severity.

“These findings suggest that CM [childhood maltreatment] may disrupt adaptive belief updating in interpersonal contexts, contributing to later vulnerability to psychopathology. The results highlight the potential value of targeting social cognitive processes, particularly belief updating, in interventions aimed at improving social functioning and psychological resilience among individuals with a history of CM,” the study authors concluded.

The study contributes to the scientific understanding of the consequences of childhood maltreatment. However, it should be noted that the assessment of childhood maltreatment used in this study was based on the recall of childhood experiences when the participants were already adults. This means that results might have been affected by recall and reporting bias.

The paper, “From maltreatment to mistrust: Impaired belief updating as a mechanism linking childhood maltreatment to interpersonal and clinical outcomes,” was authored by Shir Porat-Butman, Görkem Ayas, Stefanie Rita Balle, Julia Carranza-Neira, Natalia E. Fares-Otero, Alla Hemi, Billy Jansson, Antonia Lüönd, Tanja Michael, Dany Laure Wadji, Misari Oe, Roxanne M. Sopp, Tanya Tandon, Ulrich Schnyder, Monique Pfaltz, and Einat Levy-Gigi.

An analysis of the National Health and Nutrition Examination Survey data of older adults found no independent association between visceral adiposity and cognitive performance. While some correlations were initially found, these disappeared after the study authors controlled for sociodemographic factors and clinical conditions. The paper was published in Medicine.

Adiposity refers to the accumulation of body fat. It reflects the amount and distribution of fat tissue in the body. While some adiposity is normal and necessary for energy storage, insulation, and hormone regulation, excessive adiposity increases the risk of metabolic and cardiovascular diseases. Body fat is not uniform, and its health impact depends greatly on where it is located.

One specific type of adiposity is visceral adiposity. Visceral adiposity refers specifically to fat stored deep inside the abdominal cavity, surrounding organs such as the liver, pancreas, and intestines. This visceral fat is metabolically active and releases inflammatory molecules and hormones that disrupt glucose and lipid metabolism.

High visceral adiposity is strongly linked to insulin resistance, type 2 diabetes, hypertension, and heart disease, often more so than general obesity. In contrast, subcutaneous fat stored under the skin is less harmful and sometimes even protective when overall weight is stable. People may have a normal body weight yet still exhibit high visceral adiposity, a condition sometimes called “normal-weight obesity.”

Study author Long He and his colleagues note that previous studies indicated an association between excess adiposity and age-related cognitive decline in older individuals. They also note that visceral adiposity has been associated with a heightened risk of metabolic disorders. With this in mind, the authors investigated whether visceral adiposity is associated with cognitive performance in older adults.

The study authors analyzed data from the National Health and Nutrition Examination Survey (NHANES) 2011 to 2014. This is an epidemiological survey that uses a complex sampling system to obtain nationally representative data on the health and nutritional status of U.S. civilians.

To estimate visceral fat, the researchers used the Visceral Adiposity Index (VAI), a calculated score based on waist circumference, Body Mass Index (BMI), triglycerides, and HDL cholesterol. They analyzed data from 1,323 participants who were 60 years of age or older and for whom data on all cognitive assessments was available. These individuals completed the NHANES cognitive battery consisting of three tests: the CERAD Word List Learning Test, which measures immediate and delayed verbal memory; the Animal Fluency Test (AFT), which assesses semantic retrieval and executive functioning; and the Digit Symbol Substitution Test (DSST), which evaluates processing speed, attention, and working memory.

Results showed that after controlling for demographic factors and participants’ health conditions, there was no statistically significant association between participants’ VAI scores and their performance on the cognitive tests. While some of the cognitive tests showed associations with VAI scores before all demographic and clinical factors were taken into account, these associations disappeared after full adjustment.

“Age- and lifestyle-adjusted analyses showed inverse, domain‑specific links between higher VAI and cognition (most notably processing speed), but these weakened after full sociodemographic and clinical adjustment, suggesting measured sociodemographic and cardiometabolic factors largely explain the crude associations,” the study authors concluded.

The study contributes to the scientific understanding of the links between visceral adiposity and cognitive performance. However, it should be noted that visceral adiposity contributes to several of the clinical conditions the study authors controlled for (such as dyslipidemia). In doing so, the statistical models may have removed the part of the relationship between visceral adiposity and cognitive performance that acts through those factors.

The paper, “Association between visceral adiposity index and cognitive dysfunction in US participants derived from NHANES data: A cross-sectional analysis,” was authored by Long He, Cheng Xing, Xueying Yang, Shilin Wang, Boyan Tian, Jianhao Cheng, Yushan Yao, and Bowen Sui.

An experimental study of heavy drinkers found that smoking cannabis with 7.2% THC reduced their alcohol urge immediately after smoking. These participants consumed 27% less alcohol after smoking, while those smoking cannabis with 3.1% THC consumed 19% less alcohol. The research was published in the American Journal of Psychiatry.

Cannabis is a psychoactive plant that contains chemical compounds called cannabinoids. The most well-known cannabinoids are tetrahydrocannabinol (THC) and cannabidiol (CBD). THC is primarily responsible for the intoxicating effects, while CBD has non-intoxicating properties. CBD is studied for potential therapeutic uses.

Cannabis can be consumed by smoking, vaporizing, or ingesting extracts and edibles. The effects vary widely based on dose, potency, and individual sensitivity. Cannabis use leads to short-term changes in attention, memory, and coordination. In some individuals, it can trigger anxiety or paranoia. Long-term heavy use tends to lead to dependence, impaired cognitive functioning, or exacerbation of mental health conditions, particularly in vulnerable populations.

Some individuals use cannabis and alcohol together, but co-use can amplify impairment more than either drug alone. Alcohol is generally more often used as it is more socially accepted and is also legal in most jurisdictions. In contrast, cannabis is illegal in many countries around the world and more heavily stigmatized. However, the number of jurisdictions legalizing the use of cannabis is increasing.

Study author Jane Metrik and her colleagues wanted to explore how the consumption of cannabis affects cravings for alcohol and subsequent alcohol consumption. These authors note that results of previous studies on this are inconclusive. While some studies indicated that cannabis use might hinder alcohol dependence treatment and reduce abstinence, other studies reported no effects or even reduced consumption of alcohol after cannabis use.

The study randomized 157 individuals recruited from the community who endorsed the use of alcohol and cannabis; 138 participants completed at least two sessions and were included in the final analysis. Participants were required to be English speakers between 21 and 44 years of age, who had used cannabis during the past month two or more times weekly (and also two or more times weekly during the past 6 months), who had THC in their urine, who were familiar with smoking cannabis, and who were also prone to heavy episodic drinking of alcohol. Heavy episodic drinking was defined as having 5 or more alcoholic drinks per occasion for men and 4 or more drinks for women.

A standard alcoholic drink is defined as containing about 14 grams of pure ethanol. This is roughly equivalent to a small beer (350 ml), a glass of wine (150 ml), or a shot of spirits (45 ml).

All participants completed three experimental sessions in randomized orders. In one session they smoked cannabis with 3.1% THC, in another they smoked cannabis with 7.2% THC, and the third experimental session was a placebo session during which they smoked cannabis with almost no THC (0.03%). Experimental sessions were at least 5 days and no more than 3 weeks apart.

Before each experimental session, participants were told to abstain from cannabis and tobacco for 15 hours and from alcohol for 24 hours. They were also instructed to abstain from drinking caffeinated beverages for 2 hours before an experimental session.

Each experimental session started with a set of tests related to alcohol and cannabis levels, states related to the use of these substances, and several other assessments, including an assessment of alcohol craving. They also consumed lunch.

After this, participants smoked their assigned cannabis cigarettes. Next, they completed a test examining participants’ reactivity to alcohol cues (sight and smell of alcohol). In the end, they completed two alcohol choice tasks during which they were given an opportunity to either drink up to 8 mini-drinks of their choice or to receive $3 per drink not consumed.

Results showed that smoking cannabis had no effect on general cravings for alcohol (measured by the Alcohol Craving Questionnaire). Alcohol craving levels were similar in all three experimental conditions. However, after smoking 7.2% THC cannabis cigarettes, the specific urge to drink alcohol (measured by a single “urge” question) decreased significantly. Participants who smoked these cigarettes drank 27% less alcohol on average (compared to the placebo condition), while their alcohol consumption was 19% lower after smoking 3.1% THC cigarettes.

“Following overnight cannabis abstinence, smoking cannabis acutely decreased alcohol consumption compared to placebo,” study authors concluded.

The study contributes to the scientific understanding of the effects of cannabis on alcohol consumption. However, it should be noted that study participants were individuals who used cannabis frequently, with over 3 in 4 meeting criteria for current cannabis use disorder. They were also heavy alcohol drinkers. Because of this, they might have developed tolerance for the effects of these two substances. Results in individuals who use alcohol and cannabis less frequently might differ.

The paper, “Acute Effects of Cannabis on Alcohol Craving and Consumption: A Randomized Controlled Crossover Trial,” was authored by Jane Metrik, Elizabeth R. Aston, Rachel L. Gunn, Robert Swift, James MacKillop, and Christopher W. Kahler.

A study investigating the effects of alcohol on emotion recognition and empathy found that alcohol impairs the recognition of anger, but not other specific emotions. Participants who drank alcohol also reported higher affective empathy, i.e., relating better to other study participants. The research was published in Scientific Reports.

After a person drinks alcohol, it is rapidly absorbed through the stomach and small intestine into the bloodstream. The alcohol then travels to the brain, where it affects the release of neurotransmitters, producing relaxation and reduced inhibition. As blood alcohol concentration rises, judgment, coordination, and reaction time become increasingly impaired. The liver begins metabolizing alcohol, but it can only process a limited amount per hour, causing excess alcohol to circulate in the body.

Alcohol also affects the cardiovascular system by dilating blood vessels, which can create a sensation of warmth while actually lowering core body temperature. In the short term, drinking can increase urine production, leading to dehydration and electrolyte imbalance. The gastrointestinal system may become irritated, resulting in nausea or vomiting at higher doses.

As alcohol continues to circulate, it disrupts normal sleep, reducing restorative REM sleep despite making people feel sleepy. When blood alcohol levels begin to fall, withdrawal-like symptoms such as anxiety or irritability may appear in some individuals.

Study author Lakshmi Kumar and their colleagues investigated how an intoxicating dose of alcohol (0.74 g/kg in females and 0.82 g/kg in males) affects cognitive and affective empathy. As prior studies were inconclusive, they started this investigation with no specific hypotheses about the directions of the expected effect.

Study participants were 156 individuals who reported drinking at least one day per week and binge drinking at least four times in the past month. Participants’ average age was 23 years. Thirty-one percent of participants were women.

Binge drinking was defined as 5 or more standard alcoholic drinks on the same occasion for men and 4 or more for women. A standard alcoholic drink is a drink containing about 14 grams of pure ethanol. This is roughly equivalent to a small beer (350 ml), a glass of wine (150 ml), or a shot of spirits (45 ml).

Participants were randomly assigned to groups of 3 unacquainted persons. Each of these 3-person groups was then randomly assigned to either drink an alcoholic beverage or a placebo beverage. In this way, 117 participants were assigned to drink alcohol and 39 to drink the placebo beverage. However, participants did not know which beverage they would be drinking – they all believed that they would be drinking alcohol.

The alcoholic beverage was a cranberry-vodka cocktail dosed for each participant to achieve a peak blood alcohol concentration of 0.08%. The placebo drink was flattened tonic water, and study authors showed these participants false blood alcohol level recordings to maintain their belief that they were drinking alcohol.

After drinking the assigned drink, participants completed 3 assessments of subjective intoxication experience and blood alcohol level (using a breathalyzer) in 30-minute intervals. While the blood alcohol level was increasing after drinking, participants completed assessments of empathy and emotion recognition (MET and GERT, tests based on recognizing emotions of people in photographs and in short video clips).

Results showed that participants who drank alcohol had impaired recognition of anger, but no other specific emotions. These individuals also reported higher affective empathy, i.e., that they related well to another participant, in response to direct interactions with other participants.

“Findings suggest alcohol worsens anger recognition and increases perceptions of relating to another,” the study authors concluded.

The study contributes to the scientific understanding of the psychological effects of alcohol. However, study authors note that participants interacted in groups of strangers (other study participants they were not previously acquainted with) prior to completing the emotion recognition and empathy assessments. Differences in these interaction experiences could have affected participants’ levels of engagement and subsequently reported empathy.

The paper, “Alcohol’s acute effects on emotion recognition and empathy in heavy-drinking young adults,” was authored by Lakshmi Kumar, Kasey G. Creswell, Kirk W. Brown, Greta Lyons, and Brooke C. Feeney.