However, our new research suggests rather than cause heart disease, depression in people aged 45 or older can signal the early signs of the disease and the need for a heart check.
How are depression and heart disease linked?
To say one thing causes another, we first need to understand how the two things are linked, including which comes first.
Does depression lead to an event like a heart attack? Or are there early signs of heart disease – which make people much more likely to have a heart event – that lead to depression?
We know depression has physical effects on the body, some of which may harm the heart. Depression can increase inflammation, heart rate and blood pressure, all of which are involved in developing heart disease.
However, it’s also true people with early heart disease can feel physically lousy long before a life threatening heart event.
Half of people who survive a heart attack say they had heart disease symptoms leading up to it. The most common early signs were fatigue, shortness of breath and pains in the chest, arm, neck or back. If experienced for long periods of time these symptoms can leave a person feeling depressed.
Depression can also be linked to heart disease through behaviours and other chronic diseases. Smoking, not exercising enough, heavy drinking and poor diet, and chronic conditions like diabetes, are all more common in people with depression. These are all also factors involved in developing heart disease.
So before we can claim depression breaks your heart, we must account for the fact some behaviours and chronic diseases are more common in this group, and some people may have depression because of the early signs of heart disease.
We used data from more than 150,000 people 45 years or older who had not already had a heart attack or stroke.
At the start of the study people reported their level of psychological distress, a commonly used measure of symptoms of depression and anxiety. We then followed them over five years to see how many developed heart disease.
People with the highest levels of psychological distress were 70% more likely to go on to have a heart event (like a heart attack) within the next few years than people with the lowest levels of psychological distress.
After taking smoking, exercise, alcohol, weight and diabetes into account, this dropped to just 40%.
When we excluded people with early signs of heart disease, there was little evidence psychological distress increased the risk of developing heart disease at all.
This suggests it’s more helpful to view depression as something that signals a higher risk of heart disease, rather than as a direct cause of the disease.
This is in line with findings from other large-scale studies and robust trials. These have found treating depression does not reduce the risk of developing heart disease. If depression caused heart disease, we would have expected treating depression to have reduced the chance of developing heart disease.
If you have depression, get a heart check
The finding that depression is unlikely to cause heart disease suggests depression in people aged 45 or older might be an important sign of other things going on.
If you’re 45 or older, while you’re with your doctor, ask for a heart check. This is the first step to assessing your future risk of heart disease. It also helps your doctor find the best way to lower your risk.
If you think you may be experiencing depression or another mental health problem, contact your general practitioner or in Australia, contact Lifeline 13 11 14, beyondblue 1300 22 4636 or SANE Australia 1800 18 7263.
The term and even diagnosis of “depression” can have different meanings and consequences. Depression can be a normal mood state, a clinical disorder, and even a disease.
If your favourite soccer team loses, you might feel emotionally depressed for a few minutes. If you were a player on the team and you brought about the loss, your state of depression and self-criticism might last much longer. Both can be viewed as normal “depressed mood” states.
Such states are common, with a study of university students finding that 95% of individuals had periods of feeling depressed, being self-critical and feeling hopeless every 6-8 weeks. So we should accept that a “depressed mood” is a universal and common experience. For most, the depressed mood is transient because the person will come to terms with the cause, or its cause will cease to exist over time, or be neutralised in some way.
There’s no precise boundary between “depressed mood” states and “clinical depression”, but differences lie in impairment, symptoms and duration. Clinical depression is associated with distinct impairment (such as “absenteeism” with the individual unable to get to work, or “presenteeism” where the individual gets to work but the depression compromises their performance). Symptoms common in clinical depression include loss of appetite, sleep and libido changes, an inability to be cheered up, an inability to experience pleasure in life and a lack of energy. Clinical depression generally lasts months or years if untreated.
Current formal classification manuals tend to view clinical depression as a single condition simply varying by severity (major depression versus a set of minor depressions, regrettably including normal depressive moods). For the sake of discussing the causes of depression, I’ll look at two distinct types of depression: melancholia and the situational depressions.
Biological and disease-like depression
The key “biological” depressive disorder is melancholia. For some 2000 years, this was more viewed as a movement disorder rather than a mood disorder due to it showing “psychomotor disturbance”. This means the individual is slow to move or speak, lacking energy and unable to be cheered up, or agitated – wringing their hands, pacing up and down and repetitively uttering phrases. In addition, those with melancholia lose the capacity to find pleasure in life or be cheered up. They also lack energy and experience appetite and sleep changes.
A small percentage of those with melancholic depression develop “psychotic depression”. This is where an individual experiences delusions or hallucinations, often of derogatory voices telling them they’re worthless and better off dead, or of pathological guilt. For those with a bipolar disorder, most depressed episodes are melancholic or psychotic depression in type.
Melancholia has a strong genetic contribution, with a study quantifying a three times greater history of depression in family members of those with melancholia. If one parent has melancholia, their child has a 10% chance of developing the same; if both parents have melancholia, the chance is approximately 40%.
Once termed “endogenous depression” as it seemed to come from “within” rather than being caused by external stressors, episodes are generally more severe and persistent than would be expected from depression caused by environmental stressors. It doesn’t respond to counselling or psychotherapy and requires medication (most commonly an antidepressant drug but also perhaps other drug types). The psychotic form requires an antipsychotic drug in addition to an antidepressant.
There are a number of differing classes of antidepressants. The SSRIs (selective serotonin reuptake inhibitors) are viewed as increasing levels of the neurotransmitter serotonin in the brain and so correct the “chemical” disturbance underlying many depressive conditions. However, in melancholia it’s thought that there are also disturbances in other neurotransmitters such as noradrenaline and dopamine. Melancholia is therefore more likely to respond to the broader action antidepressant drugs such as the serotonergic and noradrenergic reuptake inhibitors (SNRIs) and tricyclics (TCAs), with the latter targeting all three implicated neurotransmitters.
In recent years, studies have not only implicated dysregulation in brain chemicals (“neurotransmitters”), but also in brain network circuits in those with melancholia. Disruptions in the circuits linking the basal ganglia (situated at the base of the forebrain and associated with emotion) and the pre-frontal cortex (the brain region implicated in personality expression and social behaviour) result in depressed mood, impaired cognition and psychomotor disturbance. These are, in essence, the key features of melancholia.
Brain imaging studies have also identified disrupted function in circuits and networks linking the insula (a brain region associated with awareness of our emotions) to other regions in the frontal cortex. These indicative findings are being progressively advanced by highly technical brain imaging strategies, and so in future years should clarify the multiple functional and structural changes that occur in the brain for those with melancholia.
There’s no “test” to diagnose biological depression, with former methods falling out of fashion due to inaccuracy, so diagnosis relies on the doctor identifying its characteristic features, excluding environmental factors and weighting a family history of depression.
Psychological and social depression
Non-melancholic depression is generally induced by a social stressor. A diagnosis of “reactive depression” captures a clinical, non-melancholic disorder caused by the individual experiencing a social stressor that impacts and compromises self-esteem. This could be a boyfriend or employer berating a young woman to the point where she feels worthless.
In many ways, such scenarios are similar to a “normal” depressed mood state, but more severe. Here we would expect the individual to come to terms with or neutralise the stressor, or even spontaneously improve across all clinical parameters after weeks. A chronic environmentally or socially driven non-melancholic depression generally reflects an ongoing stressor that the individual cannot escape. An example would be a wife who lives with a constantly abusive husband, but is unable to leave him due to having a number of young children and no money of her own.
Other non-melancholic disorders are principally driven by psychological or personality-based factors – with actual episodes generally triggered by social stressors. Research has identified a number of personality styles that put people at risk:
those with high levels of general anxiety who are at risk of depression because of their worrying, catastrophising propensities, and their tendency to take things too personally
“shy” people who are often this way due to having been bullied or humiliated in their early years. They often view social interactions with others as threatening in comparison to the safety of their own company
those who are “hypersensitive” to judgement by others. This could be praise or
feeling (perhaps inappropriately) they are being rejected or abandoned. These people often respond by sleeping more and craving certain foods that may settle their emotional dysfunction
“self-focused” individuals who are hostile and volatile with others, blame others when things go wrong and prioritise their own needs. When depressed, they tend to show a “short fuse” and create collateral damage for those around them
those who were neglected or abused in their early years and who therefore have low basic self-worth. They often repeat such cycles of deprivation and abuse in their adult relationships, and so readily become depressed
perfectionists who are prone to self-criticism and a loss of pride. They may also have a limited range of adaptive strategies to stress.
There are several brain regions implicated in these non-melancholic mood states and disorders. A key site is the amygdala (an almond-shaped region in the brain that processes emotional reactions) which shows a heightened response when an individual is depressed.
So, we should reject a “one size fits all” model for considering “depression” and instead favour a “horses for courses” model. There are multiple types of depression (normal and clinical), with the latter reflecting differing biological, psychological and social causes and therefore requiring treatments that address the primary causal factor.
Been a while. It’s been a while for many things, but I especially mean this Blog – at the moment anyway. The truth – I couldn’t be bothered. That is, I couldn’t be bothered to post here in recent times. Why? I have struggled with many things other recent years – it’s called undiagnosed depression. It’s the depression you have that you haven’t seen anyone about, yet you know what it is and still try to live in denial. But that has changed a little – I’m no longer in denial, I just couldn’t be bothered seeing anyone about it. You know, it will work out in the end – whenever that might be.
Having said that, things are a lot brighter at the moment. Have I turned a corner – I hope so. It feels like I have, with a measure of joy returning to what had become a rather miserable existence. I guess the fact that I’m writing anything (well typing) here is a sign that perhaps I have – turned a corner I mean. I’m sure there will be some setbacks ahead, but at the moment, I’m just taking in the sunshine and enjoying the rays as they fall on my face, with that gentle breeze refreshingly drifting across the surface of my face. It is time to once again step out into the wide world and enjoy the life I have been given.
Over the Christmas ‘silly season’ I hope to pitch my tent beside a river in the mountains and just take some time out and read, sleep and relax. I’m going to try and catch my breath and think about the year ahead – all with positive intent. I want to think about some of the good things that may lay ahead – especially think about and plan some wilderness excursions, where I can really enjoy the solitude of the Australian wilderness in a wonderful, soul recharging way – alone with my Creator in His creation. I have really enjoyed that in the past and look forward to doing so once again. Anyway, my first opportunity to do so is only days away – should be good.
For those of you who may not know it yet – I think I may be going mad (slightly so anyway). So in an effort to head off said madness I decided to go out for the day and went to Gloucester, visiting my mother while there and also maintaining a couple of geocaches along the way and hiding a few others.
So I have a couple of new geocaches currently awaiting review and another couple that I am yet to place on the geocaching website (I’ll do so in the next couple of days).
Did it take away my madness – probably not, but neither was there any mad, evil cackling while hiding them. So it was a start I guess.
Putting up a post on this Blog is hopefully an indication that I’m beginning to get back on track. This has been a particularly difficult period for me and I’m sure I’m not out of the woods just yet. I do feel I have turned a corner though and that is a very good think – I think.
To help me get back on track I’m actually taking a week off work from Christmas Eve until New Year’s Day, returning the following day. I’m really looking forward to a week of sleep, rest and relaxation.
The last several months (and indeed the majority of the year – if not longer) has been marked by the haphazard and irregular nature of my posting to my Blogs and the updating of my websites. This is likely to continue for some time and for an indefinite period of time. Why? I have been battling depression (essentially), though I have no real understanding of why/how it has come about. A number of years ago I was involved in a car accident that nearly killed me and I suffered a brain injury as a result of the accident. I am as fully recovered as I am likely to be and it has not really left a great permanent impact on my life – though this depression may prove to have been its lasting legacy.
I have thought of closing down the Bogs and websites on a number of occasions – but have not really wanted to do so. I would like to return to them with the same enthusiasm that I once had, though I am obviously unsure when that will be. Also, closing down the sites would be like yielding to the mental illness and sliding further down the slippery slope, which is not something I want to do. So it’s six of one and half-dozen of the other as regards what to do.
So if you have been a regular reader/user of my sites I ask for your continuing patience and understanding – normal service is something I am aiming at returning to. I just don’t know when that can/will be.
It has been such a long time since I sat down and read a book – even a chapter. I have found that when I get down/depressed I just don’t want to read – even though it would probably lift my spirits. It just seems too hard to do. This is something I hope to correct starting tomorrow – I probably should start this right now as tomorrow I will probably decide against it. The only reason I won’t start today is I am simply too tired and I need to get to bed soon. This post will remind me to do so
tomorrow – I hope.
It has been such a long time since I’ve posted to this Blog and a lot has been going on – maybe not so much in the physical realm, as life in that sphere has been pretty boring really. There have been many mental and spiritual battles, and who really knows if any useful progress has been made at all. I think I may be coming to terms with depression, not that I have seen anyone about that. It has just been something I have been in denial about for so long and I am finally beginning to accept it as a reality in my life. I’m not likely to see anyone about it either – that’s just the way I am. But accepting it as a reality is really a major step and a step that will help me to move on from it as well. That is how I see it and it seems to be the way that life is progressing. I think even writing about it in a post such as this is also something that will assist me to move on and ‘recover’ as well.
I also know what the issues are – or at least a good number of them and I am seeking to address those as well. So hopefully there is some useful progress being made in all of this. Time of course is something that is required and it has been and will undoubtedly continue to be what is required as I move forward with my life. I certainly don’t intend to spill the beans on everything in this post (or any future post for that matter), as I am an intensely private person – and yeah, I accept that that probably doesn’t help me a great lot (being an intensely private person) and will probably mean a slower journey going forward.
I have issues with trusting people, so opening up to others is not something that I do easily. Having been hurt in the past it is difficult to trust people quickly and to share with them those things that are of heart concern to me. I have done so in the past with special people, that I regarded as being people I thought highly about (and still do – even though those relationships probably no longer exist) and viewed as quality people. I am also sure that given the right circumstances I will come across these highly valued types of people again and will be able to share my life experiences with them – but not just at the moment, as they simply don’t exist in my life for the time being.
I miss one person in particular and there is no way that I will have those precious moments again. She has been gone for some years now and I miss her like none other. I visit here from time to time in her final earthly resting place, but it has also been a long time since I have done that. I think I need to go again soon. I haven’t been for so long because it is a difficult place to go and my heart breaks when I do. I miss her so much and it was perhaps her passing that started me on my downward spiral – or at the very least accelerated it, not that I have reached a terrible dark place with little light – it is not that bad. No, it began before she died – but missing her has made this time all the more difficult.
It has been a long time – but it is now well beyond time to move forward from this place of sadness, darkness and difficulty, and to leave the black dog behind. May it be so.