Spending the morning hours in dim indoor lighting may cause healthy individuals to exhibit biological changes typically seen in people with depression. A study published in the Journal of Psychiatric Research indicates that a lack of bright light before noon can disrupt sleep cycles and hormonal rhythms. These physiological shifts suggest that dimly lit environments could increase a person’s vulnerability to mood disorders.

The human body relies on environmental cues to regulate its internal clock. This system is known as the circadian rhythm. It dictates when we feel alert and when we feel ready for sleep. The most powerful of these cues is light. When sunlight enters the eye, it signals a region of the brain called the suprachiasmatic nucleus. This brain region then coordinates hormone production and body temperature. In a natural setting, humans would experience bright light in the morning and darkness at night.

Modern life has altered this natural pattern. Many people spend the vast majority of their waking hours inside buildings. The artificial light in these spaces is often far less intense than natural daylight.

Jan de Zeeuw, Dieter Kunz, and their colleagues at St. Hedwig Hospital and Charité–Universitätsmedizin Berlin have spent years investigating this phenomenon. They describe this lifestyle as “Living in Biological Darkness.” Their previous research found that urban residents spend approximately half of their daytime hours in light levels lower than 25 lux. For comparison, a cloudy day outside might measure over 1,000 lux.

The researchers wanted to understand the specific consequences of this low-light lifestyle. They were particularly interested in how it affects the hypothalamic-pituitary-adrenal axis. This system controls the release of cortisol. Cortisol is often called the stress hormone. In a healthy person, cortisol levels peak early in the morning to help wake the body. These levels then gradually decline throughout the day and reach their lowest point in the evening. This rhythm allows the body to wind down for sleep.

In patients diagnosed with depression, this rhythm often malfunctions. Their cortisol levels frequently remain elevated throughout the day and into the evening. Another biological marker of depression involves specific changes in sleep architecture. Sleep is composed of different stages, including rapid eye movement, or REM, and deep slow-wave sleep.

Depressed patients often experience a shift in deep sleep from the beginning of the night to later cycles. The researchers aimed to see if dim light alone could induce these depression-like symptoms in healthy volunteers.

The study recruited twenty healthy young adults to participate in a controlled experiment. The group consisted of ten men and ten women with an average age of about twenty-four. To ensure accuracy, the participants maintained a consistent sleep schedule for a week before the testing began. The researchers monitored their adherence using wrist-worn activity trackers.

The participants were randomly divided into two groups. The experiment focused on the morning hours between 8:00 AM and 12:00 PM. For five days, one group spent these hours in a room with low-intensity incandescent lighting. This light measured 55 lux and had a warm, yellowish color temperature. This environment simulated a dimly lit living room or a workspace with poor lighting.

The second group spent the same morning hours in a room with higher-intensity fluorescent lighting. This light measured 800 lux and had a cooler, bluish tone. This intensity mimics a brightly lit office or classroom. It served as a control condition. During the afternoons and evenings, participants left the laboratory and went about their normal lives. They returned to the lab for specific testing sessions.

The research team used several methods to track biological changes. They collected urine and saliva samples to measure hormone concentrations. They focused on cortisol and melatonin. They also utilized polysomnography to record sleep patterns. This involves placing sensors on the head to measure brain waves during the night. The team also assessed the participants’ mood and reaction times using standard psychological tests.

The findings revealed distinct differences between the two groups. The participants exposed to the dim incandescent light showed a disruption in their cortisol rhythms. Their cortisol levels were elevated in the late afternoon and evening. This elevation occurred at a time when the hormone should ideally be decreasing. The statistical analysis showed that this increase was not a random fluctuation. The result mirrors the blunted circadian rhythm often observed in depressive illnesses.

Sleep patterns in the dim light group also deteriorated. After repetitive exposure to low morning light, these individuals slept for a shorter duration. On average, their total sleep time decreased by about twenty-five minutes. The internal structure of their sleep changed as well. Deep sleep is characterized by slow-wave activity in the brain. Typically, the bulk of this restorative sleep occurs in the first few cycles of the night.

In the dim light group, this slow-wave activity shifted. It decreased in the earlier part of the night and appeared more frequently in later sleep cycles. This delay in deep sleep is a known characteristic of sleep architecture in patients with depression. The participants in this group also reported feeling subjectively worse. They rated themselves as sleepier and sadder after days of low light exposure compared to the bright light group.

The group exposed to the brighter fluorescent light did not show these negative markers. Their cortisol levels followed a more standard daily curve. Their deep sleep remained anchored in the early part of the night. The researchers did note one specific change in this group. The bright light appeared to increase the amount of REM sleep they experienced toward the end of the night.

The study suggests that light intensity affects more than just vision. It serves as a biological signal that keeps the body’s systems synchronized. The “master clock” in the brain requires sufficient light input to function correctly. This input comes largely from specialized cells in the retina that are sensitive to blue light. Incandescent bulbs, like those used for the dim group, emit very little blue light. Fluorescent bulbs emit more of these wavelengths.

When the brain does not receive a strong morning light signal, the circadian system may weaken. This weakening can lead to a misalignment of internal rhythms. The researchers note that the suprachiasmatic nucleus has direct neural pathways to the adrenal glands. This connection explains how light—or the lack of it—can directly influence cortisol production.

The authors propose that the observed changes could represent a “vulnerability” to depression. The participants were healthy and did not develop clinical depression during the short study. However, their bodies began to mimic the physiological state of a depressed person. The combination of high evening cortisol and disrupted sleep creates a physical environment where mood disorders might more easily take root.

The researchers stated, “In healthy subjects repetitive exposure to low-intensity lighting during pre-midday hours was associated with increased cortisol levels over the day and delayed slow-wave-activity within nighttime sleep, changes known to occur in patients with depressive illnesses.”

They continued by noting the implications of these sleep changes. “Insomnia-like changes in sleep architecture shown here may pave the avenue to more vulnerability to depression and contribute to the understanding of pathophysiology in depressive illnesses.”

There are limitations to this study that should be considered. The sample size was relatively small, with only ten people in each group. A larger pool of participants would provide more robust data. The design compared two different groups of people rather than testing the same people under both conditions. This introduces the possibility that individual differences influenced the results.

Additionally, the researchers could not control the light exposure participants received after leaving the lab at noon. While they wore activity monitors, these devices cannot always perfectly track light intake. However, previous studies by the same team suggest that urban residents generally encounter low light levels throughout the day. It is plausible that the participants did not receive significant bright light in the afternoons to counteract the morning dimness.

Future research should investigate these effects over longer periods. A study lasting weeks or months could determine if these biological changes eventually lead to psychological symptoms. It would also be beneficial to test different light sources, such as LED lighting, which is now common. Understanding the specific wavelengths of light that best support the circadian rhythm is an ongoing area of scientific inquiry.

The findings carry practical implications for building design and public health. They suggest that the standard lighting found in many homes and offices may be insufficient for biological health. Increasing light levels during the morning could serve as a simple preventative measure. This might involve using brighter artificial lights or designing spaces that admit more daylight.

The concept of “Living in Biological Darkness” highlights a mismatch between human biology and the modern environment. Our bodies evolved to expect bright mornings. Depriving the brain of this signal appears to set off a chain reaction of hormonal and neurological disruptions. While a few days of dim light may not cause immediate harm, chronic exposure could erode mental resilience.

Jan de Zeeuw and his co-authors argue that it is time to reconsider how we light our indoor spaces. They suggest that integrating bright light into schools, workplaces, and nursing homes could improve overall health. By mimicking the natural rising of the sun, we may be able to stabilize our internal rhythms. This stabilization could protect against the physiological precursors of depression.

The study, “Living in biological darkness III: Effects of low-level pre-midday lighting on markers of depression in healthy subjects,” was authored by Jan de Zeeuw, Claudia Nowozin, Martin Haberecht, Sven Hädel, Frederik Bes, and Dieter Kunz.

A new pilot study suggests that engaging in indoor hydroponic gardening can improve mental well-being and quality of life for adults undergoing cancer treatment. The findings indicate that this accessible form of nature-based intervention offers a practical strategy for reducing depression and boosting emotional functioning in patients. These results were published in Frontiers in Public Health.

Cancer imposes a heavy burden that extends far beyond physical symptoms. Patients frequently encounter severe psychological and behavioral challenges during their treatment journeys. Depression is a particularly common issue and affects approximately one in four cancer patients in the United States. This mental health struggle can complicate recovery by reducing a patient’s ability to make informed decisions or adhere to treatment plans. Evidence suggests that depression is linked to higher risks of cancer recurrence and mortality.

Pain is another pervasive symptom that is closely tied to emotional health. The perception of pain often worsens when a patient is experiencing high levels of stress or anxiety. These combined factors can severely diminish a patient’s health-related quality of life. They can limit social interactions and delay the return to normal daily activities.

Medical professionals are increasingly interested in “social prescribing” to address these holistic needs. This approach involves recommending non-clinical services, such as art or nature therapies, to support overall health. Gardening is a well-established social prescription known to alleviate stress and improve mood. Traditional gardening provides moderate physical activity and contact with nature, which are both beneficial.

However, outdoor gardening is not always feasible for cancer patients. Physical limitations, fatigue, and compromised immune systems can make outdoor labor difficult. Urban living arrangements often lack the necessary space for a garden. Additionally, weather conditions and seasonal changes restrict when outdoor gardening can occur.

Researchers sought to determine if hydroponic gardening could serve as an effective alternative. Hydroponics is a method of growing plants without soil. It uses mineral nutrient solutions in an aqueous solvent. This technique allows for cultivation in small, controlled indoor environments. It eliminates many barriers associated with traditional gardening, such as the need for a yard, exposure to insects, or physically demanding digging.

“Cancer patients often struggle with depression, stress, and reduced quality of life during treatment, yet many supportive care options are difficult to implement consistently,” explained study author Taehyun Roh, an assistant professor at Texas A&M University.

“Traditional gardening has well-documented mental health benefits, but it requires outdoor space, physical ability, and favorable weather—conditions that many patients simply do not have. We saw a clear gap: no one had tested whether a fully indoor, low-maintenance gardening method like hydroponics could offer similar benefits. Our goal was to explore whether bringing nature into the home in a simple, accessible way could meaningfully improve patients’ wellbeing.”

The study aimed to evaluate the feasibility and psychological impact of this specific intervention. The researchers employed a case-crossover design for this pilot study. This means that the participants served as their own controls. The investigators compared data collected during the intervention to the participants’ baseline status rather than comparing them to a separate group of people.

The research team recruited 36 adult participants from the Houston Methodist Cancer Center. The group had an average age of 57.5 years. The cohort was diverse and included individuals with various types and stages of cancer. To be eligible, participants had to have completed at least one cycle of chemotherapy. They also needed to be on specific infusion therapy cycles to align with the data collection schedule.

At the beginning of the study, each participant received an AeroGarden hydroponic system. This device is a countertop appliance designed for ease of use. It includes a water reservoir, an LED grow light, and liquid plant nutrients. The researchers provided seed kits for heirloom salad greens. Participants were tasked with setting up the system and caring for the plants over an eight-week period.

The intervention required participants to maintain the water levels and add nutrients periodically. The LED lights operated on an automated schedule to ensure optimal growth. Participants grew the plants from seeds to harvest. The researchers provided manuals and troubleshooting guides to assist those with no prior gardening experience.

To measure the effects of the intervention, the team administered a series of validated surveys at three time points. Data collection occurred at the start of the study, at four weeks, and at eight weeks. Mental well-being was assessed using the Warwick-Edinburgh Mental Wellbeing Scale. This instrument focuses on positive aspects of mental health, such as optimism and clear thinking.

The researchers measured mental distress using the Depression, Anxiety, and Stress Scale. This tool breaks down negative emotional states into three distinct subscales. Quality of life was evaluated using a questionnaire developed by the European Organization for Research and Treatment of Cancer. This comprehensive survey covers physical, role, cognitive, emotional, and social functioning.

In addition to psychological measures, the study tracked dietary habits. The researchers used a module from the Behavioral Risk Factor Surveillance System to record fruit and vegetable intake. They also assessed pain severity and its interference with daily life using the Short-Form Brief Pain Inventory.

The analysis of the data revealed several positive outcomes over the eight-week period. The most consistent improvement was seen in mental well-being scores. The average score on the Warwick-Edinburgh scale increased by 3.8 points. This magnitude of change is significant because it exceeds the threshold that clinicians typically view as meaningful.

Depression scores showed a statistically significant downward trend. By the end of the study, participants reported fewer depressive symptoms compared to their baseline levels. This reduction suggests that the daily routine of tending to plants helped alleviate feelings of despondency.

The researchers also found improvements in overall quality of life. The participants reported better emotional functioning, meaning they felt less tense or irritable. Social functioning scores also rose significantly. This indicates that participants felt less isolated and more capable of interacting with family and friends.

Physical symptoms showed some favorable changes as well. Participants reported a significant reduction in appetite loss. This is a common and distressing side effect of cancer treatment. As appetite improved, so did dietary behaviors. The frequency of vegetable consumption increased over the course of the study. Specifically, the intake of dark green leafy vegetables and whole fruits went up significantly.

“We were surprised by how quickly participants began experiencing benefits,” Roh told PsyPost. “Positive changes in wellbeing and quality of life were already visible at four weeks. Many participants also reported enjoying the sense of routine and accomplishment that came with caring for their plants—something that was not directly measured but came up frequently in conversations.”

The researchers also observed a decreasing trend in pain management scores. However, these particular changes did not reach statistical significance. It is possible that the sample size was too small to detect a definitive effect on pain.

The mechanisms behind these benefits likely involve both physiological and psychological processes. Interacting with plants is thought to activate the parasympathetic nervous system. This system is responsible for the body’s “rest and digest” functions. Activation leads to reduced heart rate and lower stress levels.

Psychologically, the act of nurturing a living organism provides a sense of purpose. Cancer treatment often strips patients of their autonomy and control. Growing a garden restores a small but meaningful degree of agency. The participants witnessed the tangible results of their care as the plants grew. This success likely reinforced their feelings of self-efficacy.

The study also highlights the potential of “biophilia” in a clinical context. This concept suggests that humans have an innate tendency to seek connections with nature. Even a small indoor device appears to satisfy this need enough to provide therapeutic value. The multisensory engagement of seeing green leaves and handling the plants may promote mindfulness.

“Even a small, indoor hydroponic garden can make a noticeable difference in mental wellbeing, mood, and quality of life for people undergoing cancer treatment,” Roh said. “Hydroponic gardening also makes the benefits of gardening accessible to nearly anyone—even older adults, people with disabilities, individuals with limited mobility, or those living without outdoor space.”

“Because it can be done indoors in any season, it removes barriers related to climate, weather, and physical limitations. You don’t need a yard or gardening experience to benefit—simply caring for plants at home can boost mood and encourage healthier habits.”

Despite the positive findings, the study has some limitations. The sample size of 36 patients is relatively small. This limits the ability to generalize the results to the broader cancer population. The lack of a separate control group is another constraint. Without a control group, it is difficult to say with certainty that the gardening caused the improvements. Other factors could have contributed to the changes over time. Additionally, the study lasted only eight weeks. It remains unclear if the mental health benefits would persist after the intervention ends.

“This was a pilot study with no control group, and it was designed to test feasibility rather than establish causation,” Roh explained. “The improvements we observed are encouraging, but they should not be interpreted as proof that hydroponic gardening directly causes better mental health outcomes. Larger, controlled studies are needed to confirm and expand on these findings.”

“Our next step is to conduct a larger, randomized controlled trial with longer follow-up to examine sustained effects and understand which patient groups benefit most. We also hope to integrate objective engagement measures—such as plant growth tracking or digital activity logs—to complement self-reported data. Ultimately, we aim to develop a scalable, evidence-based gardening program that can be offered widely in cancer centers and community health settings.”

“Patients repeatedly told us that caring for their plants gave them something to look forward to—a small but meaningful source of joy and control during treatment,” Roh added. “That human element is at the heart of this work. Our hope is that hydroponic gardening can become a simple, accessible tool for improving wellbeing not only in cancer care, but also in communities with limited access to nature.”

The study, “Indoor hydroponic vegetable gardening to improve mental health and quality of life in cancer patients: a pilot study,” was authored by Taehyun Roh, Laura Ashley Verzwyvelt, Anisha Aggarwal, Raj Satkunasivam, Nishat Tasnim Hasan, Nusrat Fahmida Trisha, and Charles Hall.

New research published in PLOS One finds that childhood trauma may worsen outcomes and increase risks in mindfulness meditation programs designed for managing depression.

Mindfulness-Based Cognitive Therapy (MBCT) was originally developed to prevent relapse in people who had recovered from depression. It combines meditation practices with cognitive therapy techniques. Over time, MBCT and similar mindfulness-based programs have been offered to people experiencing active depression. While many participants report improvements, researchers have begun to notice that not everyone responds in the same way.

Previous studies hinted that childhood trauma might influence how well mindfulness programs work. In some cases, trauma survivors benefited more from MBCT when it was used to prevent relapse. But when treating active depression, the picture was less clear. Some participants with trauma histories struggled to improve, and reports of meditation-related adverse effects – such as anxiety, panic, or traumatic memories resurfacing – raised concerns.

A research team at Brown University in Rhode Island set out to explore this gap. Led by Nicholas K. Canby, they conducted two clinical trials. The first involved 52 participants (average age 47 yrs, 79% female), while the second included 104 (average age 40 yrs, 74% female). All participants had symptoms of depression, and some had past or subclinical post-traumatic stress disorder (PTSD).

In the first study, participants were randomized to an MBCT program or a waitlist control group. In the second study, participants were assigned to standard MBCT, focused attention meditation, or open monitoring practices

“The MBCT module followed the standard session-by-session manual, while the [focused attention meditation] and [open monitoring practices] curriculums emphasized specific forms of meditation that are both present in standard MBCT,” Canby and colleagues explained.

Researchers measured depression symptoms before and after treatment, tracked dropout rates, and asked participants about any unexpected or unpleasant experiences during meditation.

Across both studies, childhood trauma predicted worse depression outcomes. In particular, childhood sexual abuse consistently emerged as a strong predictor of poor depression outcomes across both studies, and was significantly linked to higher dropout rates in the larger second study.

Emotional neglect and emotional abuse were also linked to less improvement in depression symptoms. Participants with trauma histories were more likely to report meditation-related side effects, ranging from vivid imagery and heightened anxiety to dissociation and emotional blunting. Some described feeling trapped or overwhelmed during body-focused meditation practices, which triggered memories of past abuse.

The authors concluded, “childhood trauma predicts poorer outcomes in MBCT treatment for active depression yet better outcomes when MBCT is used as a relapse prevention program in remitted individuals who are not currently depressed.”

Canby and colleagues emphasize that meditation is not inherently harmful, but that trauma survivors may need additional support or modifications to standard programs. For example, shorter meditation sessions, smaller group sizes, or trauma-informed guidance could help reduce risks.

The study does have limitations. The participants were mostly female, white, and highly educated, meaning the findings may not apply to all groups. Additionally, one of the trials lacked a non-meditation control group, making it harder to determine whether the negative outcomes were specific to mindfulness or part of a broader treatment challenge.

The study, “Childhood trauma and subclinical PTSD symptoms predict adverse effects and worse outcomes across two mindfulness-based programs for active depression,” was authored by Nicholas K. Canby, Elizabeth A. Cosby, Roman Palitsky, Deanna M. Kaplan, Josie Lee, Golnoosh Mahdavi, Adrian A. Lopez, Roberta E. Goldman, Kristina Eichel, Jared R. Lindahl, and Willoughby B. Britton.