Using talking therapies to help deal with depression may cut the risk of suffering a heart attack or stroke in later life, a new University College London study suggests.
Previous research has advocated that those affected by depression and anxiety are more likely to suffer from cardiovascular problems.
Now this latest study published in the European Health Journal, has found that using psychological or talking therapy to treat depression in adults over the age of 45 may be linked to reduced rates of cardiovascular disease – including stroke and heart disorders – as well as help the brain.
The research included 636,955 adults over the age of 45 with depression who had completed a course of psychological therapy and didn’t have cardiovascular disease or dementia.
It found that depression improvement was linked with a 15% fall in the risk of cardiovascular disease in the 45-60 age group compared to no improvement.
The equivalent figure for those 60 years and over was 6%.
In addition, 45 to 60-year-olds with improved depression had a 22% decreased likelihood of death during follow-up compared to not improving. Those 60-plus had a 15% reduction.
Study author, Céline El Baou, a PhD student at University College London, said: “This study is the first to establish a link between psychological therapy outcomes and future risk of cardiovascular disease.
“The findings are important as they suggest that the benefits of psychological therapy may extend beyond mental health outcomes and to long-term physical health.”
She added that the study emphasises the need to ensure that psychological treatments are more widely available and accessible as a means of tackling mental and physical health problems.
“This is especially relevant for certain groups who face barriers to accessing psychological therapies and are at greater risk of cardiovascular disease. Collaborative care systems where specialists from both disciplines work together could be one way to make treatment more accessible and obtain better outcomes overall.”
There are a number of different talking therapies available to help people deal with stress, anxiety and depression. They include cognitive behavioural therapy (CBT), the aim of which is to help patients explore and change how they think about their life, and free them from unhelpful patterns of behaviour.
Guided self help is another form of treatment where a person works through a CBT-based workbook or online course with the help of a therapist. Other types of talking therapy include counselling, and behavioural activation that aims to help people to take simple and practical steps to deal with depression and enjoy life again.
Cardiovascular diseases are the leading cause of death worldwide. An estimated 18.6 million people died from this cause globally in 2019.
Previous studies have shown that the risk of cardiovascular disease is approximately 72% higher among people with major depressive disorders compared to their healthy peers.
The University College London study is the first to look at whether reducing depression symptoms with psychological therapy is associated with a lower likelihood of future cardiovascular disease.
The average age of those who took part was 55 years, and 66% were women.
Information on psychological treatment, incidence of cardiovascular disease and death was obtained from national electronic health record databases in England and linked at the individual level. 
Depression level was assessed before and after therapy using the Patient Health Questionnaire-9, which gives a score of 0 (not at all) to 3 (nearly every day) for nine items.
These included:
- Little interest or pleasure in doing things
- Feeling down, depressed, or hopeless
- Trouble falling or staying asleep, or sleeping too much
- Feeling tired or having little energy
- Poor appetite or overeating
- Feeling you are a failure or have let yourself or your family down
- Trouble concentrating on things
- Moving or speaking slowly or being fidgety or restless
- Thoughts that you would be better off dead, or of hurting yourself in some way.
Depression was defined as a score of 10 or more.
Improvement in depression was defined as a reduction of six points or more in the PHQ-9 score and no worsening of anxiety between the start and end of treatment.
Anxiety was included in the definition so that the outcome of therapy was not considered good if depression improved but anxiety worsened.
Patients were followed for new onset all-cause cardiovascular disease, coronary heart disease, stroke and all-cause mortality.
The follow-up began 365 days after the last therapy session. Those with a cardiovascular event during this period were excluded to reduce the likelihood that previously undiagnosed disease was the cause of depression.
During a median follow up of 3.1 years, depression symptoms improved in 373,623 (59%) participants and didn’t in 263,332 (41%).
There were 49,803 cardiovascular events and 14,125 participants died.
Improvement of depression was associated with 12%, 11%, 12% and 19% lower risks of any cardiovascular disease, coronary heart disease, stroke and all-cause mortality, respectively, compared to no improvement.
The analyses were adjusted for characteristics that could influence the relationships such as age, ethnicity, gender, socioeconomic deprivation and other health conditions.
Ms El Baou said: “The findings are consistent with previous research suggesting that interventions to modify risk factors for cardiovascular disease are more effective at a younger age. This highlights the value of receiving help early to gain the most benefit.” 
The study’s authors noted that the results do not definitively prove that reductions in cardiovascular disease were caused by relief of depression.
In addition, data was missing on lifestyle behaviours such as smoking and inactivity which could raise susceptibility to cardiovascular disease and limit the effect of psychological treatment.
Despite this, the study has been welcomed by cardiology experts. Professor Sir Nilesh Samani, Medical Director of the British Heart Foundation, commented: “This study shows that successful treatment of depression using psychological therapies is associated with lower subsequent risk of heart and circulatory diseases, including heart attacks and strokes.
“While observational, it provides further evidence that brain and heart health are connected, and that treating depression may have other significant benefits beyond improving mental health.”
He added a word of caution, however. “More research is needed to demonstrate whether the therapy is actually causing the reduction in heart and circulatory conditions, and if so, how,” he said.
Dr Camilla Nord, Group Leader at the University of Cambridge’s MRC Cognition and Brain Sciences Unit, said the study provided “robust support” for a link between improved mental health following psychological therapy and a reduction in the future risk of cardiovascular disease.
“The sample is large and very comprehensive, including all the IAPT services in England. This study provides an important piece of the puzzle in understanding the well-established comorbidity between cardiovascular disease and depression, which could help reduce the risk of morbidity and mortality in mental health conditions.”
Bur she also commented: “There are two notable limitations. At present, we do not know the causality of the association: other factors could have driven the finding, for example, psychological therapy might be less effective for depression in patients who already have a high risk of cardiovascular disease.
“We also do not know what could be driving this effect—for example, could a reduction in depression following therapy cause lifestyle changes (such as increased exercise) that reduce cardiovascular risk?
“If other types of research, such as randomised controlled trials, discover this relationship is causal, psychological therapies could one day be recommended for patients with depression to improve long-term physical health, not just mental health.”
