A new large-scale genetic study suggests that different mental health conditions may have far more in common at a biological level than previously thought. Researchers from the University of Colorado Boulder and Mass General Brigham in the United States said the findings of this study could eventually improve how mental health conditions are diagnosed and treated, especially for people who live with more than one diagnosis.

The study analysed DNA from more than six million people, including over one million diagnosed with at least one mental health condition. According to the World Health Organization, more than a billion people worldwide live with mental health challenges.

“Right now, we diagnose psychiatric disorders based on what we see in the room, and many people will be diagnosed with multiple disorders. That can be hard to treat and disheartening for patients,” said Andrew Grotzinger, assistant professor of psychology and neuroscience at the University of Colorado Boulder and corresponding author of the study.

The research examined 14 psychiatric disorders and found that most of the genetic differences between people with and without these conditions could be explained by just five broad genetic patterns. These patterns involved 238 genetic variants that influence brain development and function. Based on these shared features, researchers grouped the conditions into five categories.

One group included disorders with compulsive traits, such as anorexia nervosa, Tourette’s disorder, and obsessive-compulsive disorder. Another encompassed internalising conditions, including depression, anxiety, and post-traumatic stress disorder. A third group focused on substance use disorders, while a fourth covered neurodevelopmental conditions such as autism and attention-deficit hyperactivity disorder. The final group included bipolar disorder and schizophrenia, which were found to share around 70 percent of their genetic signals.

“Genetically, we saw that they are more similar than they are unique,” Grotzinger said, noting that these two conditions are rarely diagnosed together but have overlapping biological roots.

The findings challenge the traditional view that mental health conditions are largely separate illnesses. Instead, the study suggests that many disorders may be driven by common biological processes. While the results are not yet being used to change diagnostic practices, the team hopes they will inform future updates to the Diagnostic and Statistical Manual of Mental Disorders, the handbook used by mental health professionals worldwide.

“This work provides the best evidence yet that there may be things that we are currently giving different names to that are actually driven by the same biological processes,” Grotzinger said. “By identifying what is shared across these disorders, we can hopefully come up with strategies to target them in a different way that doesn’t require four separate pills or four separate psychotherapy interventions.”

The study also identified specific biological pathways linked to different disorder groups. For example, genes affecting excitatory neurons were more active in bipolar disorder and schizophrenia, while variants linked to oligodendrocytes, cells that maintain the brain’s wiring, were more common in depression and anxiety. Some shared genetic factors may influence brain development even before birth, while others act later in life, potentially explaining why multiple conditions often occur in the same person.

Adults who received at least one dose of a COVID-19 vaccine have a lower risk of death, regardless of the cause, according to a new study conducted in France. The research shows that individuals vaccinated with at least one mRNA COVID-19 dose had a reduced risk of mortality compared with those who remained unvaccinated.

The study examined 28 million French adults aged 18 to 59 and tracked outcomes over a median period of 45 months. Researchers found that vaccinated individuals had a 74 percent lower risk of dying from severe COVID-19 and a 25 percent lower risk of death from all causes. The protective effect was attributed not only to the vaccines’ strong defense against severe infection but also to fewer complications related to long COVID, which may contribute to overall mortality reduction.

The research was conducted by Epi-Phare, a scientific interest group overseen by the French National Agency for Medicines and Health Products Safety (ANSM), in collaboration with the French National Health Insurance Fund. The team analysed data from the French National Health Data System, comparing 22.7 million people vaccinated between May and October 2021 with 5.9 million unvaccinated individuals as of November 1, 2021.

During the follow-up period, 98,429 deaths from all causes (0.4 percent) occurred among vaccinated participants, compared with 32,662 deaths (0.6 percent) among the unvaccinated. The study found no evidence of increased mortality from cancer, cardiovascular disease, accidental injury, or any other major cause. In every category, vaccinated individuals had equal or lower death rates than their unvaccinated counterparts.

Researchers concluded that a causal link between mRNA vaccination and excess long-term mortality appears highly unlikely, underscoring the safety and efficacy of the vaccines.

The study is the largest to date assessing the long-term safety of COVID-19 mRNA vaccines in the general adult population. The findings, however, are limited to adults under 60 and do not directly reflect outcomes for older populations, who face the highest risk from COVID-19.

In the European Union, more than 976 million COVID-19 vaccine doses had been administered as of February 2023, according to the European Centre for Disease Prevention and Control (ECDC). Vaccination programs have continued, with tens of millions of additional booster doses given each season.

The research provides robust evidence supporting the long-term benefits of COVID-19 vaccination in reducing deaths from the virus and other causes. Public health experts say the findings may reassure vaccine-hesitant individuals and reinforce the importance of ongoing vaccination efforts, particularly among younger adults who may perceive their risk from COVID-19 as low.

This study adds to a growing body of international research demonstrating that mRNA COVID-19 vaccines are both safe and effective, offering protection not only against severe illness but also against overall mortality in the adult population.

A major scientific review has concluded that children can safely follow vegetarian or vegan diets, provided they receive the right supplements or consume foods fortified with essential nutrients. The findings, published in Critical Reviews in Food Science and Nutrition, assessed how plant-based eating patterns affect growth, health, and nutrient intake among young people.

Researchers examined data from nearly 49,000 children and teenagers across 18 countries, comparing those who followed vegetarian, vegan, and omnivorous diets. The study’s lead author, Monica Dinu of the University of Florence, said the results show that plant-based diets can support healthy development when they are carefully planned. She stressed that key nutrients must be monitored to avoid deficiencies.

The review found that vegetarian children typically consumed more fibre, iron, folate, vitamin C, and magnesium than their meat-eating peers. However, their intake of energy, protein, fat, vitamin B12, vitamin D, and zinc was lower. Similar patterns were observed among vegan children, whose calcium intake was notably low. According to the researchers, vitamin B12 was consistently inadequate without fortified foods or supplements.

Study co-author Jeannette Beasley of New York University noted that children on vegetarian and vegan diets may require supplementation for nutrients such as vitamin B12, calcium, iodine, and zinc. These gaps were most evident among vegans, who avoid all animal products, including dairy and eggs.

Despite these shortcomings, the review identified several health advantages linked to plant-based diets. Both vegetarian and vegan children showed signs of stronger cardiovascular health compared with omnivores. The study reported lower cholesterol levels, including reduced low-density lipoprotein (LDL) cholesterol, which is associated with a higher risk of heart disease. Vegetarian children were generally slightly shorter and leaner, with lower body mass index and fat mass, though these differences remained within healthy ranges.

The authors cautioned that interpreting the results has limitations. It remains difficult to determine whether the diets themselves caused the observed health outcomes. Families adopting plant-based eating patterns may also differ in lifestyle or socioeconomic factors that influence children’s health.

Given the increasing number of households adopting plant-based diets for ethical, environmental, or health reasons, researchers urged parents to seek guidance from paediatricians or dieticians when planning meals for children. They also called for more official recommendations to help families ensure adequate nutrient intake during key stages of growth.

Dinu said the team hopes the findings will help families better understand the potential benefits and risks associated with plant-based diets, enabling them to make informed decisions that support children’s long-term wellbeing.