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.

Sleep disturbances are among the most debilitating symptoms of Alzheimer’s disease. It often appears years before significant memory decline and other symptoms.

A new study from researchers at the University of Kentucky suggests that this sleep loss may not be permanent.

Instead, it could be driven by an immune response in the brain that may be reversible, sparking hope for new treatments.

Published in the journal Alzheimer’s & Dementia, the study found that brain immune cells called microglia, rather than amyloid plaques themselves, are the primary cause of sleep disruption in Alzheimer’s disease.

In mouse-based trials, researchers were able to restore more than two hours of sleep per day by temporarily removing these immune cells, without reducing amyloid plaques.

Can Sleep Be Restored In Alzheimer’s Patients?

For years, scientists believed that sleep problems in Alzheimer’s were caused by the accumulation of amyloid plaques or the gradual death of brain cells. However, this study points in a different direction.

Researchers discovered that when amyloid plaques begin forming in the brain, they activate microglia, the brain’s resident immune cells.

Instead of protecting the brain, these cells cause inflammation that keeps brain circuits active, preventing sleep.

Using a drug called pexidartinib (PLX3397), the researchers temporarily depleted around 87% of microglia in Alzheimer’s mouse models.

This restored over two hours of daily sleep, particularly non-rapid eye movement (NREM) sleep, which is essential for tissue repair, memory strengthening, and clearing waste products from the brain.

Notably, the improvement occurred without changing amyloid plaque levels, suggesting that inflammation is manageable.

Also read: Captain ‘Sully’ Sullenberger, ‘Miracle On The Hudson’ Pilot, Reveals Early-Stage Alzheimer’s Diagnosis

'Paradigm Shifting' Findings

Lead researcher Dr. Shannon L. Macauley, associate professor of physiology at the University of Kentucky College of Medicine, said, “Basically, we showed that it is not the plaques themselves, or solely dysfunctional neurons, that cause sleep loss but actually microglia.

Microglia are immune cells that, when they respond to plaques, kick off this elaborate cascade of inflammation, as if the microglia are partying all night, and keeping the brain awake.”

She also highlighted why losing restorative sleep can accelerate disease progression.

“That restorative sleep is super important for physical repair, learning and memory and washing out the toxins of the day. When Alzheimer’s patients lose this stage, they lose their brain’s primary cleaning cycle, creating a feed-forward loop that may drive further damage,” she explained.

First author Dr. Nicholas J. Constantino said one of the biggest surprises was that sleep problems did not worsen as amyloid plaques increased.

“I expected that as plaque burden became more severe, sleep disruption would also worsen. The disruptions in sleep… did not worsen by 18 months, despite more than double the amount of plaque burden,” Constantino said.

Also read: What Is Type 3 Diabetes? Insulin Resistance In The Brain That Could Trigger Alzheimer’s

Why Do Alzheimer’s Patients Lose Sleep?

Poor sleep and Alzheimer’s create a vicious cycle. Sleep deprivation reduces the brain’s ability to clear amyloid-beta and tau proteins, which can accelerate disease progression, while worsening sleep.

Sleep disturbances affect up to half of people living with Alzheimer’s disease. The disease disrupts sleep due to various reasons:

Overactive microglia: As shown in the new study, immune cells become chronically activated by amyloid plaques, releasing inflammatory signals that keep the brain in a heightened state of activity.

Damage to sleep-regulating brain regions: Alzheimer’s progressively affects areas like the hypothalamus and brainstem that regulate the sleep-wake cycle.

Loss of NREM sleep: Due to lack of deep sleep, the brain’s ability to clear metabolic waste, including amyloid plagues weakens.

Circadian rhythm disruption: Degeneration of the brain’s internal clock leads to broken sleep and daytime drowsiness. This fuels confusion and agitation associated with the disease.

Obesity has always been considered as one of the contributors to heart disease, diabetes, and stroke.

Now, growing research suggests that excess body fat, particularly in your 40s and 50s, may also accelerate brain aging and raise the risk of long-term cognitive decline.

Researchers say that obesity is not just linked with memory problems but also to significant changes in the brain structure.

Maintaining a healthy weight, especially during midlife, could help prevent memory problems and overall cognitive decline.

Higher BMI Linked To Faster Brain Aging

A recent study by researchers at the University of Georgia followed more than 8,200 adults aged 50 years and older for nearly 24 years.

The researchers found that individuals whose body mass index (BMI) increased over time experienced faster declines in cognitive performance than it would with normal aging. Excess body weight affected several aspects of cognition, including memory, planning, decision-making, problem-solving, emotional regulation, and concentration.

Lead author Dr. Claire Sexton (University of Georgia College of Public Health) said, "Maintaining a healthy body weight throughout adulthood may be an important strategy for preserving cognitive health later in life."

The study adds to the evidence that preventing weight gain throughout adulthood could become crucial for reducing dementia risk.

Also read: Grade-1 Fatty Liver: More Indians Are Developing It at Lower BMIs. What's Behind the Shift?

How Does Obesity Affect The Brain?

Chronic Inflammation

Obesity causes chronic low-grade inflammation, which can potentially damaging neurons essential for learning and memory.

Insulin Resistance

The brain relies on glucose for energy. Insulin resistance, common in obesity, may impair how brain cells use glucose, affecting memory and thinking.

Reduced Blood Flow

Obesity increases the risk of hypertension, atherosclerosis and vascular disease, reducing blood supply to brain tissue and potentially accelerating cognitive decline.

Visceral Fat

Experts believe visceral fat, the fat surrounding internal organs, may be more damaging than body weight alone. It produces inflammatory chemicals linked to brain changes and dementia risk.

Also read: Beyond Weight Loss: Scientists Discover How Exercise Can Help Reverse Muscle Aging

Growing Evidence

The latest findings are supported by several years of research. A large review published in Practical Neurology concluded that obesity is associated with smaller hippocampal volume, temporal lobe atrophy, mild cognitive impairment and increased Alzheimer's disease risk.

Some studies have suggested that obesity during midlife may nearly double the risk of developing Alzheimer's disease or dementia later in life.

Another review on obesity and aging reported that higher BMI is associated with poorer verbal memory, slower information processing and reduced executive function, particularly among older adults.

In January 2026, researchers also used genetic analyses to suggest that obesity and high blood pressure may directly contribute to dementia.

Can The Risk Be Reduced?

With a few lifestyle improvements, overweight and obese individuals can maintain a healthy BMI, reducing the risk of faster brain ageing and cognitive degradation. Experts recommend focusing on overall metabolic health rather than the number on the weighing scale alone.

Maintaining a healthy weight, regular exercise, controlling blood pressure, cholesterol and diabetes, following a Mediterranean diet, getting adequate sleep, remaining socially and mentally active can help maintain a healthy body weight.

Living with someone who has hepatitis can be worrying. People tend to immediately wonder whether they are at risk simply by sharing meals, hugging, or living under the same roof.

Fortunately, the answer depends on the type of hepatitis, and in most cases, everyday household contact does not spread the virus.

Dr. Shalimar, Prof. Department of Gastroenterology, AIIMS explains, "Hepatitis means inflammation of the liver. There can be many causes, but viral hepatitis is one of the most common. There are different hepatitis viruses, including A, B, C, D, and E. Some cause acute illness, while others can lead to long-term liver damage, including cirrhosis and liver cancer."

Experts say misinformation surrounding hepatitis often leads to unnecessary fear and stigma, causing patients to feel isolated. Understanding how different hepatitis viruses spread can help families protect themselves without avoiding normal interactions.

Can You Get Hepatitis By Living With Someone?

Dr Nanda Kishore M, Gastroenterology, Athulya Geriatric Care Hospital, answers our question, "No, Hepatitis is not a communicable disease that spreads through everyday contact such as hugging, holding hands, coughing, or sneezing."

For most forms of hepatitis, the answer is no. However, hepatitis B is spread through contact with infected blood and certain body fluids. Household transmission is possible, but it generally occurs when infected blood enters another person's bloodstream.

Possible household risks include sharing:

• Razors
• Toothbrushes
• Nail clippers
• Glucose monitoring devices
• Any item contaminated with blood

Also read: Can Hepatitis Be Completely Cured? Understanding What Treatment Can Achieve

Dr. Kishore says that the mode of transmission largely depends on the type of hepatitis infected.

He says, "Hepatitis A and E are predominantly spread via means of contaminated food and water, while Hepatitis B and C are transmitted through infected blood and certain bodily fluids."

Hepatitis B is preventable by vaccine. Household members of someone with chronic hepatitis B are usually advised to get tested and vaccinated if they are not already immune.

Dr. Shalimar says, "For hepatitis B, current treatment controls the infection, and newer therapies under development offer hope for a functional cure in the future. Vaccination has dramatically reduced hepatitis B in many parts of the world. Expanding vaccination coverage remains one of the most effective ways to prevent the disease."

Living with a hepatitis infected individual is generally safe given that basic hygiene and recommended precautions are followed strictly. Understanding these facts helps reduce unnecessary fear and stigma associated with it.

Also read: Grade-1 Fatty Liver: More Indians Are Developing It at Lower BMIs. What's Behind the Shift?

Importance of Screening & Prevention

Living with someone who has hepatitis does not mean you need to keep your distance. Instead, focus on practical precautions:

• Never share personal items that may come into contact with blood.
• Cover cuts and wounds.
• Wear disposable gloves while cleaning blood spills.
• Practice good hand hygiene.
• Ensure hepatitis B vaccination if recommended.
• Attend regular medical follow-ups if advised by your healthcare provider.

Dr. Ankur Jain, Associate Director & Unit Head, Gastroenterology, Hepatology & Endoscopy, Max Hospital, Dwarka, explains, "Hepatitis B and Hepatitis C continue to affect millions of people worldwide and remain major causes of liver cirrhosis and liver cancer. Individuals with a history of blood transfusions before routine screening, unsafe injections, or other risk factors should discuss screening with their physician.

He adds, "The liver has an extraordinary capacity to heal, but only if we identify problems early and address the underlying causes. Prevention, timely screening, and simple lifestyle modifications remain our most powerful tools in reducing the growing burden of liver disease in India."