Happiness is influenced by a complex interplay of various chemicals in our brain, particularly four key neurotransmitters, D.O.S.E or Dopamine, Oxytocin, Serotonin, and Endorphins. These chemicals, often referred to as "happiness chemicals," are responsible for creating feelings of joy, motivation, connection, and calm.

However, when there's a deficiency in any of these, it can significantly affect our mood, energy, and overall well-being. Let’s dive into what these four neurotransmitters are, how their deficiency impacts us, and how we can boost their levels naturally.

Dopamine: The Motivation and Reward Chemical

Dopamine is often called the "motivation molecule." It plays a major role in enabling motivation, learning, and the pleasure-reward system in the brain. When we accomplish something — whether it’s finishing a project, completing a workout, or achieving a goal — dopamine gives us that sense of satisfaction and determination to continue.

Deficiency Effects:

When dopamine levels are low, it can lead to procrastination, low self-esteem, lack of focus, and general fatigue. A person might feel anxious, hopeless, or experience mood swings because the brain isn’t getting the reward signals it needs.

Boosting Dopamine:

You can increase dopamine levels by setting and achieving small goals, exercising regularly, eating foods rich in L-Tyrosine (such as almonds, avocados, and eggs), and practicing mindfulness or meditation. Engaging in creative activities like writing or drawing also helps boost dopamine levels.

Oxytocin: The Bonding Chemical

Oxytocin is often referred to as the "love hormone" or "cuddle hormone" because it plays a major role in social bonding and trust. It’s released when we hug, touch, or engage in other forms of physical affection. Oxytocin fosters feelings of connection and emotional intimacy, making it essential for relationships, family bonding, and even team cooperation.

Deficiency Effects:

A lack of oxytocin can lead to feelings of loneliness, stress, anxiety, and difficulties in forming or maintaining relationships. Low oxytocin levels are associated with feelings of isolation and disconnection from others.

Boosting Oxytocin:

You can raise your oxytocin levels through physical touch, socialising, spending quality time with loved ones, and even engaging in activities like massage or listening to soothing music. Acts of kindness, such as helping others or volunteering, also help release oxytocin.

Serotonin: The Mood Stabiliser

Serotonin is responsible for feelings of well-being and contentment. It helps regulate mood, sleep, digestion, and even social behavior. People who have balanced serotonin levels often feel calm, confident, and emotionally stable. Serotonin is crucial in helping people feel valued and significant among their peers.

Deficiency Effects:

Low serotonin levels are linked to depression, low self-esteem, irritability, and mood swings. Individuals may feel overly sensitive to criticism, experience panic attacks, or struggle with social phobias when serotonin is deficient.

Boosting Serotonin:

You can boost serotonin by getting regular exercise, exposing yourself to sunlight, engaging in cold showers or massages, and practicing mindfulness. Simple activities like walking in nature, meditating, or doing yoga are also effective serotonin enhancers.

Endorphins: The Pain Reliever

Endorphins are the body’s natural painkillers. Released in response to stress, pain, or intense physical activity, they help alleviate discomfort and promote a sense of euphoria. Endorphins are what make you feel good after a workout or a hearty laugh, often referred to as the "runner's high."

Deficiency Effects:

Without enough endorphins, people may experience anxiety, depression, chronic pain, and insomnia. A deficiency in endorphins can make daily life feel overwhelming and physically draining.

Boosting Endorphins:

To boost endorphins, engage in laughter, exercise, and stretching activities. Eating spicy foods or dark chocolate can also stimulate endorphin production. Regular massage therapy and meditation are other ways to naturally elevate endorphin levels.

Women's bodies have long been understudied, and even a simple touch can trigger unexpected sadness, anguish or homesickness. One such experience is Sad Nipple Syndrome (SNS), which many women may experience without knowing it has a name. Triggered by nipple stimulation, it remains poorly understood and largely unresearched.

Some describe it as sudden sadness or anguish, while others compare it to homesickness, nostalgia or an upsetting memory. Even putting on a shirt can trigger the sensation.

SNS is not an officially recognised medical diagnosis. Although it can affect anyone, it appears more common in women, according to the Cleveland Clinic.

Sad Nipple Syndrome Can Begin In Childhood

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Some people experience SNS from childhood without understanding what is happening.

“I was probably a child when I first noticed: ‘Why does touching my nipple make me sad?’” 28-year-old Sandra told The Guardian.

She kept the experience to herself until college, when she searched for answers online. “I realized I wasn’t crazy,” she said.

The Role Of Oxytocin And Dopamine

One possible explanation involves oxytocin, commonly known as the 'love hormone'.

Dr Vladimír Kraus from the Department of Gynaecology and Obstetrics at Pavol Jozef Šafárik University suggests oxytocin may be involved because nipple stimulation triggers its release.

Oxytocin plays a role in bonding and emotional connection. It is released during physical touch and also plays a role in childbirth and breastfeeding.

Kraus theorises that changes in oxytocin signalling could trigger negative emotions associated with SNS, although this has not been established.

A study found that breast stimulation increased oxytocin levels in both lactating and non-lactating women, suggesting the response is not limited to breastfeeding.

Maureen Sweeney, a psychiatric mental health nurse practitioner and women's behavioural health specialist at the Cleveland Clinic, suggests oxytocin release may also influence dopamine production. Reduced dopamine could contribute to dysphoric feelings, although this remains a proposed explanation.

Other possible factors include postpartum mental health, body image concerns, anxiety and intimate partner violence. Sweeney also points to premenstrual dysphoric disorder (PMDD), suggesting that some people may be more sensitive to normal hormonal fluctuations.

Read More: Breastfeeding Can Help Reduce Mothers' Risk of Type 2 Diabetes, Breast Cancer and More

How Is SNS Similar To D-MER And Post-Coital Dysphoria?

Dysphoric milk ejection reflex (D-MER) causes sudden negative emotions, such as sadness, homesickness and guilt, just before or during milk letdown while breastfeeding. It can also affect the breastfeeding experience and maternal bonding.Post-coital dysphoria (PCD), meanwhile, involves sadness, anxiety or irritability after sexual activity.

While SNS and D-MER are associated with nipple stimulation, PCD occurs after orgasm. Despite the different triggers, people can experience similar emotional and physical sensations, lactation consultant Alia Macrina Heise was quoted as saying to The Guardian.

She suggested hormonal interactions may be involved in all three conditions, although their precise mechanisms remain unclear.

Is There A Treatment For Sad Nipple Syndrome?

There are no specific treatments for SNS, and more research is needed to understand its causes. However, coping strategies and psychological support may help manage the distress. Sweeney suggests cognitive behavioural therapy (CBT) as one approach to addressing symptoms, even when a therapist is unfamiliar with SNS.

Per- and polyfluoroalkyl substances (PFAS), commonly known as forever chemicals, have sparked interests of epidemiologists who are investigating their links to chronic diseases like high blood pressure, cardiovascular conditions and certain cancers.

PFAS are a large group of chemicals made by humans that have been used in industrial processes and everyday consumer products. They are found in cosmetics, kitchen supplies, clothing, carpets, upholstery, food packaging and other household materials.

They are called forever chemicals because their strong chemical bonds make them resistant to breaking down in the environment. Some PFAS can also exist in the human body, allowing exposure to accumulate over time.

At the American Public Health Association's (APHA) 2026 Annual Meeting, researchers presented findings on how people are exposed to these chemicals everyday through food and drinking water, and what long-term health consequences may be related to that exposure.

Health Problems Linked To Forever Chemicals

Some studies have identified that PFAS exposure could lead to colon and liver cancers, low birth weight, development problems in children, complications during pregnancy and other metabolic disorders. Research has also identified its exposure to cholesterol, changes in liver enzymes, reduced antibody responses to some vaccines and hypertension during pregnancy.

However, this does not establish that PFAS exposure directly causes every condition reported in epidemiological studies. Health effects may depend on the chemical type, exposure levels, duration of exposure and individual factors.

The US Agency for Toxic Substances and Disease Registry (ATSDR) states that research into PFAS health effects is in progress.

Also read: Paper Straws Have 6.33 Times Higher Carcinogenic Risk Than Plastic Straws, Study Finds

Food Is A Significant Source Of PFAS

Besides drinking water, food can also contribute to exposure, prompting researchers to investigate whether dietary habits influence the relationship between PFAS and chronic health conditions.

One study conducted in Massachusetts examined the relationship between dietary patterns, PFAS exposure and blood pressure. Researchers found stronger associations between a specific PFAS compound and high blood pressure among people who regularly consumed fish.

Yuting Wang, a postdoctoral research fellow at Silent Spring Institute and one of the researchers involved in the study, said animal-based foods appeared to contain more PFAS than plant-based foods.

One possible explanation, she suggested, was that meat consumption could increase inflammation, which may influence the relationship between PFAS exposure and blood pressure.

"Better understanding interactions among diet, PFAS and blood pressure may improve clinical recommendations to prevent hypertension," Wang said. "Future studies should account for exposure to environmental pollutants in addition to nutrient benefits of certain food," she added.

Also read: Lancet Study Finds Air Pollution & Chemical Exposures Could Add To South Asia's Diabetes & Heart Disease Burden

PFAS Found In US Drinking Water Supplies

According to the US Geological Survey, approximately 45% of drinking water samples collected across the country showed traces of PFAS. Researchers have also investigated PFAS contamination in 11 townships in southeastern Pennsylvania. Their testing found that several drinking water supplies had PFAS concentrations exceeding the US Environmental Protection Agency's 2021 regulatory limits.

The team also examined two decades of mortality data from the townships to investigate whether areas with higher PFAS levels in public drinking water has different patterns of disease and death.

Erin Kulick, an assistant professor of epidemiology and biostatistics at Temple University College of Public Health who worked on the Pennsylvania study, said, "Southeastern Pennsylvania experiences overlapping burdens of PFAS exposure and cardiovascular disease."

Scientists Are Concerned About Long-Term Exposure

PFAS contamination is a public health concern because these chemicals can remain in the environment for long periods and reach people. Some PFAS accumulate in the body, and repeated exposure may increase the amount present over time.

The National Institutes of Health identifies several health concerns linked with exposure to certain PFAS, including immune system effects, increased cholesterol, liver changes, pregnancy-related complications and some cancers.

The US Environmental Protection Agency has established legally enforceable drinking water limits for six PFAS compounds, including perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).

Researchers say more comprehensive monitoring, better assessment and long-term epidemiological studies are needed to understand how PFAS contamination affects communities.

A simple five-factor risk score may help identify people at high risk of dementia, particularly in low- and middle-income countries (LMICs), where around 60% of the world's dementia cases now occur.

Developed and validated by researchers at Northumbria University, the risk score uses five everyday factors to identify older adults at higher risk of dementia. It aims to address a gap in dementia research, as existing prediction tools have largely been developed using data from high-income countries and may not work as well in lower-income settings.

The research team developed the model using data from more than 11,000 older adults across seven countries and three continents.

“We know the burden of dementia is shifting towards lower-income parts of the world, yet the prediction models clinicians and researchers rely on were designed with wealthier populations in mind. This model is a step towards changing that. It is simple, it is built for the settings where it is needed most, and it gives researchers a practical way to find the people who should be the focus of future studies and trials,” said Dr Eduwin Pakpahan, from Northumbria University's Applied Statistics and Data Science Research Group. The study is published in the American Journal of Epidemiology.

What Are The Five Factors Used To Predict Dementia Risk?

Also read: WHO's New Dementia Guidelines Prioritize Healthy Habits, Warn Against Supplements

The model can be applied using information gathered through a straightforward conversation with an older adult and, where relevant, a family member or carer. It does not require blood tests, brain scans or specialist equipment.

The five factors included in the risk score are:

• Age: The strongest single predictor. Dementia risk rises meaningfully from age 70 and more steeply from 80 onwards.
• Social engagement: This includes whether a person is married or living with others, how often they meet friends or family, and whether they participate in community or religious groups.
• Physical activity: The model considers how active a person is in daily life, across both work and leisure. Everyday movement, such as farming, walking to the market or doing household tasks, also counts.
• High blood pressure: Uncontrolled hypertension can damage the blood vessels supplying the brain over time. It is common, often undiagnosed in lower-income settings, and inexpensive to manage.
• Difficulty managing money: A family member or carer is asked whether the person has experienced a noticeable change in their ability to handle finances. This can be one of the early everyday signs of cognitive change.

How Does The Dementia Risk Score Work?

Each factor contributes points towards a total score ranging from 0 to 9. A person scoring 0 has around a 1% chance of developing dementia within three years, while someone scoring 9 has a nearly 19% chance.

The researchers built and tested the model across seven sites in China, Cuba, the Dominican Republic, Puerto Rico, Venezuela, Mexico and Peru. It achieved a performance score of 0.75, above the 0.70 threshold generally regarded as clinically useful.

However, the researchers emphasise that the tool is primarily intended for research rather than routine screening of the general population. It could give researchers and clinical trial teams a practical, low-cost way to identify and recruit people at higher risk of dementia.

The team has also called for the model to be validated in regions not covered by the study, particularly South Asia, the Middle East and North Africa, and Sub-Saharan Africa.

Read More: Dementia Is More Than Forgotten Birthdays, Lost Keys: Doctors Explain Early Signs Before Memory Loss

Why Is A Dementia Risk Prediction Tool Important?

Dementia affects more than 57 million people worldwide, with around 60% of cases occurring in LMICs across Latin America, the Caribbean, Asia and Africa.

Identifying people at higher risk could help researchers in these regions plan studies and clinical trials that better reflect their populations. A simple tool based on everyday information may also make risk assessment more accessible in settings where specialised diagnostic resources are limited.