Medical Bulletin 15/October/2025

Cognitive decline, which includes memory loss, reduced focus, and slower thinking, naturally occurs with aging. However, researchers from a global collaborative team wanted to understand how smoking habits might accelerate or slow this process. They examined long-term data from adults across 12 countries, tracking changes in brain performance over time, including memory, verbal ability, and mental processing speed.

Participants in the study were categorized into four groups: never smokers, current smokers, those who quit in midlife (40s or 50s), and those who quit later in life. Brain function was measured before and after smoking cessation, offering valuable insights into how timing of quitting influenced cognitive aging.

The results were clear: quitting smoking, even after decades, slowed the rate of cognitive decline. The most substantial brain health improvements were seen in adults who quit in their 40s or 50s. However, individuals who gave up smoking in their 60s or 70s also experienced measurable benefits, proving that it’s never too late to take action. Those who had never smoked showed the slowest cognitive decline overall, reinforcing that prevention is ideal but quitting at any age remained better than continuing.

The study concludes that whether you’ve smoked for years or decades, quitting now can slow brain aging and support better mental function.

Reference: Cognitive decline before and after mid-to-late-life smoking cessation: a longitudinal analysis of prospective cohort studies from 12 countries, Bloomberg, Mikaela et al. The Lancet Healthy Longevity, Volume 0, Issue 0, 100753

Not All Depression Is Alike: Study Reveals Different Types Linked to Different Health Risks

A new study presented at the European College of Neuropsychopharmacology (ECNP) Congress in Amsterdam and based on data from the Netherlands Epidemiology of Obesity (NEO) Study, reveals that not all depression is alike when it comes to health risks. The findings show that specific types of depression are associated with different long-term risks of developing cardiometabolic diseases, a significant advancement in our understanding of the depression-metabolism connection.

It has long been known that depression can increase the risk of metabolic disorders, but researchers have now found that the type of depressive symptoms matters. The research team followed 5,794 adults over a period of seven years, all of whom were free from cardiovascular disease and diabetes at the beginning of the study. Each participant completed detailed questionnaires assessing depressive symptoms, allowing scientists to categorize them into two primary profiles: those with “melancholic” symptoms and those with “atypical/energy-related” symptoms.

Melancholic depression is characterized by classic symptoms such as early morning awakening and loss of appetite. Atypical or energy-related depression, on the other hand, includes fatigue, excessive sleep, and increased appetite. These symptom profiles were not just academic distinctions, they predicted different disease outcomes over time.

According to the findings, individuals with atypical/energy-related depressive symptoms were approximately 2.7 times more likely to develop type 2 diabetes than those without depression, but did not show an increased risk of cardiovascular disease. Conversely, those with melancholic symptoms had a 1.5 times higher risk of developing cardiovascular disease, such as stroke or heart attack, but no increased risk for type 2 diabetes.

Lead researcher Dr Yuri Milaneschi (Amsterdam UNC) said

We already knew that not all depressions are the same, but this means that we may need to consider how the type of depression someone has impacts different areas of their physical health. It very much pushes us towards the idea of precision psychiatry, the idea that we need to look for physical associations with mental health profiles, so that we can better treat mental illness. To treat sufferers individually”.

Reference: https://www.ecnp.eu/congress2025/

Non-Communicable Diseases Now Cause Two-Thirds of All Deaths: Lancet Study Finds

Non-communicable diseases (NCDs) such as ischemic heart disease, stroke, and diabetes now account for nearly two-thirds of the world’s total mortality and morbidity, according to the latest Global Burden of Disease (GBD) study published in The Lancet. The report also finds a significant global rise in life expectancy, from 46.8 years in 1990 to 63.4 years in 2023, highlighting a complex global health transition driven by ageing, lifestyle, and shifting disease patterns.

The GBD 2023 study is one of the most comprehensive demographic analyses, covering 204 countries and territories. Led by Dr Christopher Murray and his team at the Institute for Health Metrics and Evaluation (IHME), the study draws on data from a global network of 16,500 researchers. It offers new estimates of all-cause mortality and life expectancy from 1950 to 2023, using a novel statistical model to account for complex demographic patterns. In total, 60.1 million deaths occurred globally in 2023, with 4.67 million in children under five. Yet, despite population growth and ageing, the age-standardised all-cause mortality rate fell by 66.6% since 1950.

The researchers observed large reductions in age-standardised rates of Years of Life Lost for respiratory infections, tuberculosis, nutritional deficiencies, and enteric infections, with declines between 58.9% and 79.0%. Simultaneously, modifiable risk factors such as high blood sugar, high BMI, and smoking have emerged as major drivers of poor health, contributing to nearly half of global death and disability.

Mental health, too, showed alarming trends: age-standardised rates of anxiety rose by 62.8% and depression by 26.3% since 2010. Alzheimer’s disease entered the top 25 causes of global disability.

“The rapid growth in the world’s ageing population and evolving risk factors have ushered in a new era of global health challenges,” said Dr Murray. The study urges policymakers to adapt to this new reality by prioritising prevention, risk reduction, and long-term chronic disease management.

Reference: Global age-sex-specific all-cause mortality and life expectancy estimates for 204 countries and territories and 660 subnational locations, 1950–2023: a demographic analysis for the Global Burden of Disease Study 2023, Schumacher, Austin E et al. The Lancet, Volume 0, Issue 0