A study of older adults in Japan found that taking a hot-tub bath before bed was associated with better sleep quality. Participants not only felt their sleep was better, but objective actigraphy data also confirmed they slept more efficiently on average compared to their peers who did not bathe before bed. This effect was particularly strong during winter. The paper was published in Sleep Health: Journal of the National Sleep Foundation.

Sleep quality refers to how well a person sleeps, including how long it takes to fall asleep, how often they wake during the night, and how rested they feel upon waking. It is not just the number of hours slept but the depth and continuity of sleep that determine its quality. High-quality sleep involves cycling smoothly through the stages of light, deep, and REM sleep without frequent interruptions.

Poor sleep quality can result from stress, irregular schedules, caffeine, alcohol, or sleep disorders like insomnia or sleep apnea. Good sleep quality supports brain function, learning, and emotional stability. It also plays a key role in physical health, aiding immune function, tissue repair, and hormone balance. Chronic poor sleep increases the risk of heart disease, obesity, diabetes, and depression. People who sleep poorly often experience daytime fatigue, poor concentration, and irritability.

Study author Yoshiaki Tai and his colleagues wanted to explore the effects of hot-tub bathing on sleep quality under real-life conditions, accounting for various factors such as bathing behaviors, environmental influences, and individual characteristics.

Hot-tub bathing is a common evening or nighttime practice in Japan. It involves being immersed in a tub filled with water heated to 40–41°C for 10–30 minutes. The bathtub is usually designed to have a depth that allows the water level to reach the mid-thorax or neck.

The researchers note that previous studies reported that hot-tub bathing before sleep was associated with lower nighttime blood pressure and a lower prevalence of nocturia (waking up from sleep to urinate).

The study included 2,252 older adults from Nara, Japan. Their average age was 69 years, and 64% were women.

Study participants wore an actigraph on the wrist of their non-dominant hand for seven consecutive 24-hour periods. An actigraph is a device that measures movement to estimate an individual’s sleep patterns, activity levels, and circadian rhythms. They also wore a wireless device that logged their skin temperature attached to the actigraph, and another temperature logger on their abdomen (however, the abdominal one was worn for 24 hours only).

Participants completed an assessment of sleep quality (the Pittsburgh Sleep Quality Index) and kept a diary of their bathing behavior. They recorded whether they took a hot-tub bath, a shower, or did not bathe before bed, as well as the start and end times of bathing and the duration of immersion. For a majority of the participants, this diary was for one day only, but 945 of them recorded it for the full 7-day period.

The study authors used these data to estimate the temperature of the water (using abdominal skin temperature as a surrogate) and the bath-to-bed interval. Baths taken more than 5 hours and 45 minutes before bedtime were classified as not having been taken before bedtime.

The results showed that participants who took a hot-tub bath before going to bed slept better than their peers who did not. Their odds of reporting poor sleep quality were significantly lower than the odds for participants who did not bathe. The odds of poor sleep for participants who took a shower were not significantly different from those who did not bathe.

Higher water temperature during bathing and longer immersion time were associated with more efficient sleep. However, there was a negative interaction between these two factors. If the water temperature went above 41.7°C or immersion lasted longer than 18.3 minutes, further increases were no longer beneficial and were associated with reduced sleep efficiency.

Furthermore, the association between hot-tub bathing and more efficient sleep was strongest and most consistent for participants studied during the winter months. In general, subjective sleep assessments agreed with actigraphy measures, indicating better sleep for participants taking hot-tub baths.

“Hot-tub bathing was associated with better self-reported sleep quality, higher SE [sleep efficiency], and shorter WASO [wake after sleep onset] in real-life settings among community-dwelling older adults. In hot-tub bathing sessions with a duration of immersion < 18.3 minutes and proximal skin temperature during bathing (used as a surrogate for water temperature in the bathtub) < 41.7°C, a longer duration of immersion and higher maximum proximal skin temperature during bathing were positively associated with higher SE [sleep efficiency]. Our results suggest that improvements in SE, WASO [wake after sleep onset], and SOL [sleep onset latency, how long it takes to fall asleep] can be maximized when hot-tub bathing is scheduled 61–120 minutes before bedtime during winter,” the study authors concluded.

The study sheds light on the links between bathing behaviors and sleep quality. However, it should be noted that this was an observational study, and researchers did not direct participants’ bathing behaviors. Because of this, definitive causal inferences cannot be drawn from the results.

The paper, “Association between before-bedtime hot-tub bathing and sleep quality in real-life settings among community-dwelling older adults,” was authored by Yoshiaki Tai, Kenji Obayashi, Yuki Yamagami, and Keigo Saeki.

An analysis of the China Health and Retirement Longitudinal Study data found that individuals with more severe depressive symptoms tend to report higher levels of social isolation at a later time point. In turn, individuals who are more socially isolated tend to report slightly worse cognitive functioning. Analyses showed that social isolation mediates a small part of the link between depressive symptoms and worse cognitive functioning. The paper was published in the Journal of Affective Disorders.

Depression is a mental health disorder characterized by persistent sadness, loss of interest or pleasure, and feelings of hopelessness that interfere with daily functioning. It adversely affects the way a person thinks, feels, and behaves. It can lead to difficulties in work, relationships, and self-care.

People with depression may experience fatigue, changes in appetite, and sleep disturbances. Concentration and decision-making can become harder, reducing productivity and motivation. Physical symptoms such as pain, headaches, or digestive issues may also appear without clear medical causes.

Depression can diminish the ability to enjoy previously pleasurable activities, leading to social withdrawal. This isolation can worsen depressive symptoms, creating a cycle of loneliness and despair. Social isolation itself is both a risk factor for developing depression and a common consequence of it.

Study author Jia Fang and her colleagues note that depressed individuals also tend to show worse cognitive functioning. They conducted a study aiming to explore the likely causal direction underpinning the longitudinal association between depressive symptoms and cognitive decline, and a possible mediating role social isolation has in this link among Chinese adults aged 45 years and above. These authors hypothesized that social isolation mediates the association between depressive symptoms and cognitive function.

Study authors analyzed data from the China Health and Retirement Longitudinal Study (CHARLS). CHARLS is a nationally representative longitudinal survey of Chinese residents aged 45 and above. This analysis used CHARLS data from three waves in 2013, 2015, and 2018, including a total of 9,220 participants. 51.4% were women. Participants’ average age was 58 years.

The authors of the study used data on participants’ depressive symptoms (the 10-item Center for Epidemiologic Studies Depression Scale), social isolation, and cognitive function (assessed with tests of contextual memory and mental integrity). A social isolation score was calculated based on four factors: being unmarried (single, separated, divorced, or widowed), living alone, having less than weekly contact with children (in person, via phone, or email), and not participating in any social activities in the past month.

Results showed that depressive symptoms were associated with subsequent social isolation. Social isolation, in turn, was associated with subsequent worse cognitive functioning. Further analyses showed that social isolation partially mediated the link between depressive symptoms and cognitive functioning, explaining 3.1% of the total effect.

The study authors concluded that the association between depressive symptoms and cognitive function is partially mediated by social isolation. They suggest that public health initiatives targeting depressive symptoms in older adults could reduce social isolation and help maintain cognitive health in middle-aged and older adults in China.

The study sheds light on the nature of the link between depressive symptoms and cognitive functioning. However, it should be noted that the design of the study does not allow definitive causal inferences to be derived from these results. Additionally, social isolation was assessed through self-reports, leaving room for reporting bias to have affected the results. Finally, the reported mediation effect was very modest in size, indicating that the link between depression and cognitive functioning depends much more on factors other than social isolation.

The paper, “Social isolation mediates association between depressive symptoms and cognitive function: Evidence from China Health and Retirement Longitudinal Study,” was authored by Jia Fang, Wencan Cheng, Huiyuan Li, Chen Yang, Ni Zhang, Baoyi Zhang, Ye Zhang, and Meifen Zhang.

An analysis of massive cognitive and neuroimaging databases indicated that more education was associated with better memory, larger intracranial volume, and slightly larger volumes of memory-sensitive brain regions. However, contrary to popular theories, education did not appear to protect against the rate of age-related memory decline, nor did it weaken the effects of brain decline on cognition. The paper was published in Nature Medicine.

As people reach advanced age, they tend to start gradually losing their mental abilities. This is called age-related cognitive decline. It typically affects functions such as memory, attention, processing speed, and problem-solving. This decline is a normal part of aging and differs from more serious conditions like dementia or Alzheimer’s disease.

Many older adults notice mild forgetfulness, slower thinking, or difficulty learning new information. Biological changes in the brain, such as reduced neural activity and decreased blood flow, contribute to this process. Lifestyle factors like lack of physical activity, poor diet, and chronic stress can accelerate cognitive aging.

On the other hand, regular mental stimulation, social engagement, and physical exercise can help maintain cognitive health. Adequate sleep and managing conditions like hypertension or diabetes also play a role in slowing decline. The rate and severity of decline vary greatly among individuals. Some people maintain sharp cognitive abilities well into old age, while others experience noticeable difficulties.

Study author Anders M. Fjell and his colleagues note that leading theories propose that education reduces brain decline related to aging and enhances tolerance to brain pathology. Other theories propose that education does not affect cognitive decline but instead reflects higher early-life cognitive function. With this in mind, they conducted a study aiming to resolve this long-standing debate.

They conducted a large-scale mega-analysis of data from multiple longitudinal cohorts, including the Survey of Health, Ageing, and Retirement in Europe (SHARE) and the Lifebrain consortium. In total, they analyzed over 407,000 episodic memory scores from more than 170,000 participants across 33 countries. For the neuroimaging component, they analyzed 15,157 magnetic resonance imaging scans with concurrent memory tests from 6,472 participants across seven countries. In their analyses, they defined brain decline as reductions over time in memory-sensitive brain regions within the same participant.

Results showed that while older age was associated with lower memory scores, the association between education level and the rate of memory decline was negligible. Individuals with a higher education level tended to have better memory throughout their lives but did not differ from their less-educated peers in the speed with which their memory declined as they aged.

Individuals with more education also tended to have a larger intracranial volume (a proxy for maximum brain size developed early in life) and slightly larger volumes of memory-sensitive brain regions.

“In this large-scale, geographically diverse longitudinal mega-analytic study, we found that education is related to better episodic memory and larger intracranial volume and modestly to memory-sensitive brain regions. These associations are established early in life and not driven by slower brain aging or increased resilience to structural brain changes. Therefore, effects of education on episodic memory function in aging likely originate earlier in life,” the study authors concluded.

The study contributes to the scientific understanding of factors affecting age-related cognitive decline by providing strong evidence that education provides a “head start” rather than acting as a shield against decline. The research focused on episodic memory because it is particularly sensitive to the effects of aging and is a key indicator in dementia research. Sensitivity analyses on other cognitive tests, such as numeric skills and orientation, showed the same pattern, strengthening the study’s main conclusion.

The paper, “Reevaluating the role of education on cognitive decline and brain aging in longitudinal cohorts across 33 Western countries,” was authored by Anders M. Fjell, Ole Rogeberg, Øystein Sørensen, Inge K. Amlien, David Bartrés-Faz, Andreas M. Brandmaier, Gabriele Cattaneo, Sandra Düzel, Håkon Grydeland, Richard N. Henson, Simone Kühn, Ulman Lindenberger, Torkild Hovde Lyngstad, Athanasia M. Mowinckel, Lars Nyberg, Alvaro Pascual-Leone, Cristina Solé-Padullés, Markus H. Sneve, Javier Solana, Marie Strømstad, Leiv Otto Watne, Kristine B. Walhovd, and Didac Vidal-Piñeiro.

A study of men seeking help for delayed or premature ejaculation in Italy found that those suffering from delayed ejaculation tended to have more severe depressive and anxiety symptoms, and lower sexual desire than men suffering from premature ejaculation. They also tended to be older. The paper was published in IJIR: Your Sexual Medicine Journal.

Premature ejaculation is a sexual condition in which a man reaches orgasm and ejaculates sooner than desired, often within a minute of penetration or with minimal stimulation. It can lead to frustration, anxiety, and reduced sexual satisfaction for both partners. The causes may include psychological factors such as stress, depression, or relationship problems, as well as biological ones like hormonal imbalances or nerve sensitivity.

In contrast, delayed ejaculation is the persistent difficulty or inability to reach orgasm and ejaculate despite adequate sexual stimulation. This condition can also cause emotional distress, relationship strain, and decreased confidence. Delayed ejaculation may result from psychological issues, nerve damage, certain medications, or chronic health conditions such as diabetes. Both conditions are forms of ejaculatory disorders and sexual dysfunction. They can occur occasionally or become chronic depending on underlying causes.

Study author Fausto Negri and his colleagues note that many men experiencing ejaculatory disorders have difficulty expressing their negative feelings and that sexuality and emotional expression are closely connected. With this in mind, they conducted a study aiming to define specific clinical and psychological profiles of individuals suffering from premature and delayed ejaculation and to investigate the association between delayed ejaculation and other domains of sexual functioning.

Study participants were 555 men who were seeking medical help for ejaculation disorders. 76 of them reported for delayed ejaculation, while the rest of them sought help for premature ejaculation. Participants’ average age was approximately 45 years. 53% of participants with delayed ejaculation reported having a stable partner, and this was the case with 64% of participants with premature ejaculation.

Participants completed assessments of erectile function (the International Index of Erectile Function) and depression (the Beck Depression Inventory). Researchers also measured levels of various hormones and collected other medical and demographic information about the participants.

Results showed that participants suffering from delayed ejaculation were older than participants suffering from premature ejaculation (average age of 47 years vs 44 years). They also more often suffered from other disorders. Participants with delayed ejaculation also tended to have more severe symptoms of depression and anxiety. Their sexual desire tended to be lower, as were their orgasmic function scores, compared to participants with premature ejaculation. The two groups did not differ in relationship status, waist circumference, body mass index, or levels of examined hormones.

“Roughly one of ten men presenting for self-reported ejaculatory dysfunction as their main complaint in the real-life setting suffers from DE [delayed ejaculation]. Usually, they are older than men with primary PE [premature ejaculation] and overall less healthy. Likewise, they depict an overall poorer quality of sexual life, with lower SD [sexual desire] and OF [orgasmic function]. Moreover, men with DE have higher chances to report clinically significant depression and anxiety, which significantly impact their overall sexual satisfaction,” the study authors concluded.

The study sheds light on the differences in psychological characteristics between people with different forms of ejaculation disorders. However, it should be noted that the design of the study does not allow any causal inferences to be derived from the results. Additionally, all participants came from the same clinical center. Results on men from other geographical areas might differ.

The paper, “Men with delayed ejaculation report lower sexual satisfaction and more depressive symptoms than those with premature ejaculation: findings from a cross-sectional study,” was authored by Fausto Negri, Christian Corsini, Edoardo Pozzi, Massimiliano Raffo, Alessandro Bertini, Gabriele Birolini, Alessia d’Arma, Luca Boeri, Francesco Montorsi, Michael L. Eisenberg, and Andrea Salonia.