When the day has been long, worries pile up and morale is flagging a little, sometimes all it takes is an enthusiastic welcome behind the door to put a smile back on your face. For millions of owners, this scene is part of everyday life. Long considered a simple impression, this sensation of well-being is now of serious interest to researchers.
A scientific review published in 2025 analyzed 116 studies devoted to the links between dogs and mental health. His observation is clear: living with a dog is often associated with better psychological balance. The benefits appear in adults, adolescents and the elderly, even if scientists advise us not to transform these results into a miracle recipe.
Why the presence of a dog seems to calm the mind
The relationship between a human and his dog is not limited to a few caresses or daily walks. In the brain, something is actually happening.
In 2019, Sarah Marshall-Pescini’s team observed that affectionate exchanges between an owner and their dog increased oxytocin levels in both. This hormone, often associated with attachment and trust, also plays a role in the bonds between parents and their children.
A few years later, another study completed the picture. Researchers found that interactions with a dog could lower the stress hormone cortisol. Result: the participants felt better after these moments spent with their animal.
But the effects don’t stop there. Having a dog also forces you to change certain habits. You have to go out, walk, meet other people at the park or in the neighborhood. This routine sometimes creates opportunities for social contact that would not otherwise exist.
This is what a research team found. Among the elderly in particular, pet owners report feeling less alone. A meta-analysis published in 2022, covering 24 studies, reached the same conclusion.
Among adolescents, particularly surprising results
The researchers were particularly intrigued by what was happening among the youngest.
In children with autism spectrum disorder, several studies show that the presence of a dog can facilitate social interactions and help ease certain everyday tensions. Other studies have also observed better mood regulation in young people facing psychological disorders.
One of the most notable studies was conducted in Japan as part of the Tokyo Teenager Cohort Study. The scientists followed 343 adolescents aged 13, 96 of whom lived with a dog.
A year later, the differences were visible. Young dog owners showed less social withdrawal, less aggression and less delinquent behavior than other participants.
The researchers even discovered something unexpected. Adolescents living with a dog had a slightly different salivary microbiota. Certain groups of bacteria, such as Streptococcus and Prevotella, were more represented.
This avenue still remains exploratory, but it opens up new questions about the links between pets, the bacteria that live in our body and our behavior.
A valuable companion, but not a miracle solution
Faced with these results, there is a great temptation to see dogs as a universal remedy for ill-being. However, researchers are much more cautious.
In the columns of The GuardianProfessor Stefan Reber, from the University of Ulm, points out that the studies mainly show associations. Clearly, people living with a dog often have better mental health, but this does not automatically mean that the dog is the sole cause of this difference.
The reality is sometimes less idyllic than the images shared on social networks. A dog who constantly pulls on his leash, destroys living room cushions or makes daily outings difficult can also become a source of additional stress.
The major review published in 2025 also highlights an essential point: it is not only the presence of the animal that counts, but the quality of the relationship built with it. The stronger the emotional bond between the owner and his dog, the greater the psychological benefits observed.
In other words, what seems to make the difference is not simply having a dog at home, but sharing a real relationship with him on a daily basis.