Your adolescence lasts well up to your 30s. A new, "cool" study as Prof Tara Spires Jones, tells BBC, noted that the human brain does not follow a simple, steady path from birth to old age. Instead, it moves through five clear phases, each marked by a shift in how its networks connect and communicate. The study is conducted by the researchers from the University of Cambridge, who analyzed thousands of brain scans to track how neural connections strengthen, weaken, and reorganize over time.

This large study involved nearly 4,000 people between infancy and age 90 and has now mapped these transitions, offering new insights into why periods of life differ so much in terms of learning, behaviors, and vulnerability to mental health conditions.

Their work shows that the brain remains in an adolescent state far longer than earlier believed and reaches a peak of efficiency only in the early thirties. The findings, published in Nature Communications, highlight striking turning points at the ages of nine, 32, 66 and 83.

The Five Phases Of Brain

Childhood: Birth to Age Nine

The study showed that during childhood, the brain grown rapidly, however, it also begins trimming the vast numbers of synapses formed in early life. This is what helps the brain decide which pathways truly matter. However, this period is not very efficient. It resembles a child wandering without a fixed route, exploring freely rather than moving directly from one point to another. The purpose is exploration, not precision.

Adolescence: Age Nine to 32

A dramatic shift begins around age nine. The brain enters a long stretch of heightened efficiency as it reorganizes its neural networks with remarkable speed and intensity.

This is the phase where mental health vulnerabilities often emerge, since the brain is restructuring at an unusually rapid pace.

This part of the study also breaks the conventional idea that associated adolescence typically with the teenage years. Modern neuroscience suggests it extends into the twenties. This study pushes that boundary even further, indicating that the adolescent phase may last all the way to 32.

During this time, the brain reaches its most efficient point, and many cognitive abilities are thought to peak.

Adulthood: Age 32 to 66

After the long adolescent stretch, adulthood brings stability. The study shows that adulthood actually comes from the age 32, again a shift from what conventionally was believed adulthood to be. This is the brain’s most settled era, lasting more than three decades. Change continues, but at a gentler pace and in a more predictable pattern. The efficiency gained earlier begins to level out. Many people recognize this phase as a period when their cognitive strengths, personality and sense of self feel most consistent. The fireworks of earlier development give way to a steady rhythm.

Early Aging: Age 66 to 83

The period after 66 marks the beginning of early ageing. It does not arrive as a sudden decline. Instead, there are subtle shifts in how different parts of the brain coordinate.

Rather than functioning as one unified network, the brain begins to break into clusters of regions that work more closely within their own groups. It is similar to a band whose members start pursuing individual projects while still occasionally performing together.

Although the study focused on healthy brains, this is also the age when conditions linked to ageing, such as high blood pressure and dementia, begin to appear more frequently.

Late Aging: 83 And Beyond

The final phase begins at around 83. Data for this group was more limited, since it is harder to find older adults with no underlying health issues. Even so, the scans show that the patterns seen in early ageing become more pronounced. The brain’s networks continue to drift apart, and communication between regions becomes less synchronized.

For many long-term cannabis users, the usual jokes about the munchies feel far removed from reality. Over recent years, emergency rooms have reported a steady rise in regular smokers arriving with sudden bouts of severe stomach distress that leave them curled up and unable to function. What makes it more troubling is that these episodes return several times a year, often leaving both patients and clinicians unsure of what is going on.

Scromiting: What is Cannabis Hyperemesis Syndrome (CHS)?

The source of the problem is cannabis hyperemesis syndrome (CHS), a difficult condition marked by unrelenting nausea, strong abdominal cramps and repeated vomiting that can occur four or five times an hour, according to the Cleveland Clinic.

What Is Scromiting?

Symptoms usually appear within a day of cannabis use and can linger for several days. These episodes can be so overwhelming that emergency staff have adopted the term “scromiting,” a blend of screaming and vomiting that captures how distressing it can be.

Although cases have become more common, many healthcare workers are still relatively unfamiliar with CHS because it was only identified in recent years. This makes it easy to confuse with other illnesses such as foodborne infections or stomach bugs.

“A person often will have multiple emergency visits before the condition is correctly identified, which can be very costly,” said Dr. Beatriz Carlini, a research associate professor at the University of Washington School of Medicine who studies the health risks linked to cannabis. Once a diagnosis is made, managing the condition can still be a challenge.

There are no approved treatments at present, and many standard nausea medications fail to bring relief, explained Dr. Chris Buresh, an emergency medicine physician with UW Medicine and Seattle Children’s Hospital.

This often pushes doctors to try less common options, including Haldol, a drug usually used to manage psychosis. Some people experience temporary improvement from applying capsaicin cream to the abdomen, as the warming sensation can help lessen discomfort for short periods.

Hot baths and showers are another frequent source of relief. Many patients report staying in the bathroom for long stretches to calm their symptoms.

“That is often something that helps confirm the diagnosis for me,” Buresh said. “People say a hot shower is the only thing that brings any comfort, and they end up using all the hot water in the home.”

Scromiting Recovery Challenges

Once the worst phase passes, long-term improvement is not always straightforward. Because CHS comes and goes, some cannabis users assume an episode was caused by something else and continue smoking, only to fall ill again, according to UW researchers.

Even for those who accept the diagnosis, quitting cannabis can be difficult due to dependence, which prolongs the cycle of nausea and vomiting, Carlini said. The only known cure is to stop cannabis use entirely.

Researchers still do not know the exact biological cause of CHS. The leading idea is that years of heavy cannabis use overstimulates receptors within the endocannabinoid system, which may disrupt the body’s usual control over nausea and vomiting, as outlined by the Cleveland Clinic.

Why this affects certain users and not others remains unclear. “We do not yet know if it is tied to wider access to cannabis, higher THC levels, or something else entirely,” Buresh said.

“There seems to be a point at which people become vulnerable to this condition, and that point varies from person to person,” he added. “Even small amounts of cannabis can trigger vomiting once someone crosses that threshold.”

A study released earlier this year by George Washington University researchers examined 1,052 people with CHS to learn more about potential risk patterns.

The findings showed that those who began using cannabis at younger ages were more likely to return to the ER with hyperemesis episodes. Many reported daily use and long-term consumption, with 44 percent using cannabis regularly for more than five years before symptoms began.

CHS is not limited to adults. Data shows that emergency visits among American adolescents have increased more than tenfold between 2016 and 2023. While overall rates tend to be higher in states where recreational cannabis is legal, the sharpest year-to-year rise in adolescent CHS cases has been recorded in states where recreational use is still against the law.

Every year on December 1, World AIDS Day reminds us that HIV continues to be a global concern, and in 2025 the focus is on "Overcoming disruption, transforming the AIDS response. Early testing and treatment are key to making that transformation real. The sooner HIV is detected and treated, the better the long-term health outcomes. India has made notable progress.

According to 2023 estimates, adult HIV prevalence is around 0.2%, and prevention and treatment programmes using medication continue to expand. Still, challenges remain: gaps in testing, delayed diagnoses, and interruptions in care persist—issues World AIDS Day 2025 urges us to address.

World AIDS Day 2025: Why HIV Diagnosis Is Important

HIV is still a very real health concern today. It can affect anyone, students, professionals, or those in stable relationships—especially if needles or syringes are shared or protection is not used.

Once HIV enters the body, it gradually weakens the immune system. If left undetected and untreated, it can progress to AIDS, leaving even minor infections dangerous. The good news is that this progression can be prevented. With early testing and proper treatment, people living with HIV can lead full, healthy, and normal lives.

Dr. R K Gattani, Senior Consultant Physician at Kailash Hospital & Heart Institute, Noida, says, "Early testing is an important form of self-care. Choosing to get tested shows you are taking responsibility for your health—it doesn’t mean something is wrong."

Meanwhile, Dr. Vaibhav Gupta, Senior Consultant in Internal Medicine, Critical Care, and Diabetology at Regency Health Kanpur, adds, "Detecting HIV early allows doctors to begin Antiretroviral Therapy (ART) straight away, keeping the immune system strong, preventing AIDS, and reducing transmission risk almost to zero. In a world where millions are diagnosed each year, early recognition is one of the strongest tools young Indians have to protect themselves and their partners."

What Is Modern Antiretroviral Therapy?

Today’s ART enables people diagnosed early to live long, healthy, and productive lives. It keeps the virus under control, safeguards the immune system, and dramatically lowers the chance of passing HIV to others. Early diagnosis also gives young people the knowledge to make safer lifestyle choices.

Dr. Aabid Amin Bhat, Medical Director at Ujala Cygnus Group of Hospitals, explains, "Encouraging open discussions, expanding access to youth-friendly testing, and fighting stigma are essential steps. When HIV is found early, it’s not the end; it’s the start of informed care, timely treatment, and a healthier future."

The challenge is that early HIV symptoms often look like common illnesses like fever, fatigue, sore throat, swollen lymph nodes, and rashes—which can be easily ignored. Without prompt testing, the virus may advance silently, making treatment more complex. Early testing also opens doors to preventive options like post-exposure prophylaxis (PEP), which can prevent infection if taken within 72 hours of potential exposure. Recognizing early signs and seeking confidential, judgment-free testing allows young Indians to stop HIV before it develops into AIDS, turning a potentially life-altering diagnosis into a manageable condition.

HIV prevention is simpler than many think. Basic precautions like using protection during intimate contact, avoiding sharing needles or items that could contact blood, and staying informed about your health—make a huge difference. Anyone who may have been exposed should immediately consult a healthcare professional for guidance. Above all, don’t hesitate to get tested, ask questions, or seek help. Taking care of your health is the most responsible and empowering way to protect your future. People living with HIV, when on proper treatment and taking necessary precautions, should not automatically be seen as a risk to others.

Education and awareness remain key. Safe practices, timely diagnosis, and access to treatment can transform HIV from a feared disease into a manageable condition, giving young Indians control over their health and future.

World AIDS Day is marked across the globe every year on 1 December to draw attention to HIV and AIDS. In India, the day is observed through awareness drives and community-level programmes held nationwide. The National AIDS Control Organization (NACO), which functions under the Ministry of Health and Family Welfare, leads these efforts and brings people together to support the ongoing battle against the illness.

This year, the government reported a strong decline in HIV cases, noting 49 per cent fewer new infections since 2010, an 81 per cent fall in deaths linked to AIDS, and a 75 per cent drop in mother-to-child transmission between 2010 and 2024.

The update, shared on Sunday for World AIDS Day 2025, also underlines how myths continue to harm people living with HIV. Misconceptions remain widespread, including the belief that the virus spreads through simple physical contact.

What is HIV/AIDS?

The Human Immunodeficiency Virus (HIV) harms the body by attacking helper T-cells, which are vital for immunity. Acquired Immunodeficiency Syndrome (AIDS) develops when these cells fall to very low levels, leaving the body exposed to infections and diseases, as described by the Mayo Clinic.

Common HIV Myths That You Should Know About

• It is a myth that HIV spreads through coughing, touching or shaking hands. Routine contact or a cough does not transmit the virus. Transmission can occur only when the skin has open sores or breaks that allow the virus to enter.
• It is a myth that a person diagnosed with HIV will survive only a short time. With proper treatment that keeps the virus suppressed, people with HIV can live for many years.
• It is a myth that every child born to an HIV-positive mother will also have HIV. With antiretroviral therapy, a planned C-section and other precautions, the chance of passing the virus to the baby can be reduced to below 2 per cent.
• It is a myth that HIV, being a viral infection, cannot be linked to the use of antibacterial or antifungal medicines. Since HIV weakens immunity, those living with it may be prone to common bacterial and fungal infections and may need such medicines for long periods.
• It is a myth that there is no risk when two or more HIV-positive partners are intimate. Unprotected sex can still allow tougher or drug-resistant strains of the virus to evolve and spread.
• It is a myth that people who do not show symptoms cannot have HIV. It can take years for signs to appear, and the only way to confirm the infection is through testing.
• It is a myth that taking medicines before intercourse can fully prevent HIV. Pre-exposure prophylaxis lowers the risk but does not remove it entirely.

World AIDS Day, observed each year on December 1, is a time to pause, acknowledge and renew our commitment. It pays respect to those who lost their lives to AIDS-related illnesses, offers support to people living with HIV and reminds the world that prevention, treatment and rights-based care remain essential. The theme for 2025, “Overcoming disruption, transforming the AIDS response”, urges countries to build stronger systems, widen access to services and uphold the dignity of all communities affected by HIV.