woman smiling at a collie dog

Human Animal Interaction

4 ways pets can help our mental health, according to science

Around 1 in 10 people worldwide are living with a mental health disorder, according to Our World in Data estimatesMental health problems have also been linked to an increased risk of developing physical health problems, and vice versa.

For this reason, an increased focus has been placed on the importance of protecting our mental wellbeing. One area of particular interest is the role that pets can play in helping us do this.

Dr. Carla J. Eatherington, Senior Research Scientist at Waltham Petcare Science Institute, shares some of the research indicating how pets may benefit our mental health:

1. Pets can help reduce depression

A growing body of research has found that pet ownership and human-animal interactions are associated with decreased levels of depression. Spending time with animals has been found to increase our levels of oxytocin, dopamine, and serotonin, collectively known as the ‘happy hormones’ because they promote a sense of wellbeing and contentment.

A study conducted at the University of Padua found that older adults in care homes had reduced levels of depression and increased quality of life after caring for a canary for three months. Another study found that after a ten week animal-assisted therapy program with a dog, patients with schizophrenia reported improvements in hedonic tone, which is linked to a person’s ability to feel pleasure.

One way that owning a pet might reduce a person’s feelings of low mood and depression is by providing them with a sense of purpose and helping maintain a routine. Pet ownership also promotes increased activity, which is recommended by medical professionals to reduce depression, whether this means walking the dog or playing with the cat.

In addition to increasing activity levels, activities such as walking the dog can also increase the number of interactions with other people in our neighbourhood we have because pets are “social lubricants” that can break down social barriers. According to some theories of psychology, this is important because it allows people to test beliefs that they hold, such as ‘nobody will talk to me’ or ‘if I speak to someone else, they will ignore me’.

2. Pets can help us feel less lonely and socially isolated

Social interactions are thought to be even more important for older adults. COVID-19 has taken a toll on our mental health over the past years, and social distancing may have disproportionately impacted aging adults already suffering from loneliness. Loneliness currently affects 3 in 5 Americans and 9 million people in the United Kingdom, and it can be as deadly as smoking 15 cigarettes per day, making it a serious threat to public health.

According to recent US market research run by HABRI in collaboration with Mars Petcare, 80% of pet owners say their pet makes them feel less lonely. This finding was also supported by controlled studies which showed that animal-assisted therapy reduced loneliness in older adults in care homes.

Over the past three decades, human-animal interaction researchers have been looking into animal-assisted therapy as a possible way of addressing older adults’ mental health illnesses. In 2019, Mars Petcare and the Human Animal Bond Research Institute (HABRI) held the first summit on social isolation and companion animals, where experts in public health, research, psychology, gerontology, and veterinary medicine highlighted the need to advance human-animal interaction research to better understand for whom and how interactions with pets may be effective for alleviating social isolation and loneliness.

3. Pets can help reduce our stress

Loneliness is also associated with an increased risk of stress. Stress is our bodies’ alarm response, which is triggered if we feel under pressure or threatened. For this reason, we all expect to feel stressed from time-to-time – but if stress becomes chronic then this is problematic, as we are over-exposed to stress hormones, such as cortisol, which have a negative impact on our physical health.

Research has found that interacting with animals can reduce the level of cortisol in our bodies. Researchers at Washington State University showed that students who interacted with a dog had lower salivary cortisol levels than students who only saw the interaction or watched videos.

Dogs have also been shown to help people suffering from post-traumatic stress disorder (PTSD). Service dogs for people with PTSD are trained to perform a range of behaviours, such as waking their owner when they are experiencing night terrors and providing tactile stimulation during anxiety attacks. In another study, military veterans who walked with shelter dogs had lower perceived stress than veterans who walked with people.


4. Pets can help reduce anxiety

A common comorbidity with stress is anxiety, which is the most frequently diagnosed mental illness. Anxiety is characterised by feelings of worry or fear, but research has shown that interacting with animals can reduce both trait and state anxiety.

For example, in a study with children it was found that their level of anxiety was reduced after interacting with a dog.

Interacting with animals has been found to be especially useful for people with autistic spectrum disorder (ASD), who find social interactions difficult and often uncomfortable. Therapeutic horseback riding has also been associated with positive, long-lasting effects in children with autism spectrum disorder. The study found children participating in the program had better social skills, were less irritable and less hyperactive than children who didn’t interact with the horses.  

In recent years, service dogs for children with autism have become increasingly popular, as they can accompany the child and reduce anxiety during things like medical visits or school activities.

More research needed to better understand the possible benefits of pet interaction

Overall, the body of evidence promoting human-animal interactions as a practical way to help support mental wellbeing is steadily increasing. However, more research is needed to understand the mechanism of action for different populations of people in specific situations: who can benefit from animal-assisted interactions and under what circumstances.

Through the decade-long National Institutes of Health/Mars–WALTHAM™ Public-Private Partnership, researchers have been exploring the impact pet ownership and animal-assisted interventions can have on both people and pets. This work has helped this field to develop and has led to new research questions, which can help improve our understanding of the human-animal bond.

Read Dr. Eatherington’s full blog here.