The title of this post is, of course, stolen from the 1992 track of the same name by The Disposable Heroes of Hiphoprisy. Yes, that’s right, they did have a startlingly naff name, but they were a good act, and also released what’s still, 17 years later, one of the very few rap tracks that directly tackles homophobia within US black culture, ‘Language of Violence‘. Anyway, that’s not what this post is about – an opportunity for me to wax nostalgic for the days when rap was still a predominantly political genre, and not a cartoonish freak-show obsessed with money, material possessions, and misogyny.*
No, what this post is actually about is this piece of research, which I found out about via the Mad World blog. Some medical researchers with quite a lot of time on their hands carried out a longitudinal study (one in which the same group of participants are followed over a lengthy period of time) in order to investigate a possible link between adolescent watching of television, and the risk of subsequently developing depression. Although the research seems to have been well designed, I do still have a few problems with it. Let’s face it, I wouldn’t be me if I didn’t…
First of all, it seems to be a very outdated concern. As I understand it, today’s adolescents watch a lot less TV than my generation did, and are much more likely to spend their time online or playing games. The researchers specifically state that
We did not find a consistent relationship between development of depressive symptoms and exposure to videocassettes, computer games, or radio
so it would seem there’s comparatively little of contemporary concern here.
One of the very impressive things about the research is that the researchers didn’t simply impose an arbitrary limit which they considered to mark the threshold between ‘normal’ and ‘excessive’ TV watching, and analyse the prevalence of depression in each group. Such an approach would have led to questions about whether there was some other difference besides TV habits between the two groups that had not been taken into account by the researchers. Instead, the researchers have analysed their data in such a way that they have been able to demonstrate that, across the group of participants as a whole, the likelihood of developing depression increases for each additional hour of television watched per day during adolescence. The clarity provided by this method of analysing the results, together with the large size of the study sample (results from 4142 participants were included in the analysis), are the main reasons that I describe this study as well designed.
Other aspects of the study were of greater concern for me. Judging by the information contained in the abstract (unfortunately I don’t have access to the whole paper), it would appear as though the participants were only tested for the symptoms of depression twice – once at the very beginning of the study, and again 7 years later. Participants who tested positive for depression at the first test were apparently excluded from the analysis of the results. There are really two concerns here.
Firstly, the researchers were clearly concerned that pre-existing depression would complicate the results from their study, since they excluded those who tested positive at the start. However, some of the participants who appeared free from depression when the study began may have simply been having a good day when they were tested. With no background information on how depressed they were in general before the study began, it is impossible to know for certain whether an individual participant has developed depression over the course of the study, or if they were pre-existing sufferers. This in turn makes it difficult to be sure whether watching more TV in adolescence was a symptom of pre-existing depression, or if it was the cause of an emerging depression. (Many of us who sufferer from depression would say that we are more likely to pursue ‘passive’ activities like watching TV when we are depressed.)
Secondly, and more significantly, with no intermediate testing of depression over the course of the 7 year period, the researchers have missed an opportunity to establish if there is an association between the presence of depressive symptoms and watching more TV. This is significant, because it means that the researchers are unable to exclude the possibility that adolescents who began by watching very little TV later developed depression, and that this caused them to watch more TV. If the researchers had tested the participants for depression at more frequent intervals (and I realise that logistical problems would have been encountered in arranging this, especially given the numbers of people participating in the study), it might have been possible to establish whether the change in behaviour preceded or followed the onset of depression. This would have enabled the researchers to take a more definite view as to whether increased TV watching was a symptom or cause of depression. Opportunities to shed light on the symptom/ cause debate regarding factors in mental illness are very rare, and as such it’s a shame that this study didn’t do that.
Instead, in their conclusion the researchers fall back on the old cliche of asserting that there is ‘an association’ between watching more TV in adolescence and developing depression in young adulthood. Such ‘associations’ may be very clear, but they don’t necessarily tell us anything useful – as I’ve mentioned before, there’s a clear ‘association’ between broken legs and plaster casts, but that doesn’t mean that plaster casts cause broken legs. The scientifically precise use of the word ‘association’ also leads to frustration because it’s often wrongly described as a ‘link’, and this is in turn misinterpreted as meaning that a ’cause’ has been discovered. In fact, the first stage of this process is in evidence when the study is reported on Mad World – the article is headed ‘Link between watching TV in adolescence and depression‘, where the original research is entitled ‘Association Between Media Use in Adolescence and Depression in Young Adulthood‘.
I’m certain that the author of the blog had no intention to mislead, and just used the word ‘link’ because it was shorter, and is so often used in media reports about scientific studies which show an association that most people now assume the terms are synonymous anyway. Certainly he doesn’t unthinkingly endorse the conclusions made by the researchers. Instead, he points out that someone who is watching a lot of TV is likely to be socialising and exercising less than their counterparts who don’t watch as much TV, and that the researchers may have simply ‘rediscovered’ by other means the already acknowledged association between social isolation and/or lack of exercise and depression.
I certainly agree with that take on things, but would also want to take it one stage further. The ‘associations’ between social isolation and lack of exercise and poor mental health are just that – associations. Some lonely and unfit people will just be lonely and unfit, and won’t go on to develop depression. Conversely, some people who take regular exercise and have positive social connections will nonetheless develop depression. One usual way round this difficulty is to speak in terms of ‘risk factors’, and to say lack of exercise increases the risk of developing depression, in the same way that smoking increases the risk of developing heart disease. Unfortunately, the association between depression and lack of exercise (or social contact) isn’t as clear and straightforward as the association between smoking and heart disease, because, unlike the latter, the former argument can be reversed.
When looking at the association between smoking and heart disease, it isn’t reasonable to speculate as to whether smoking causes heart disease, or heart disease causes smoking. That’s partly because the decision to smoke is a conscious one – people who have never smoked before will not find themselves spontaneously puffing their way through a packet of 20 in the aftermath of their first angina attack. But it’s also because of an accumulation of data which shows that people without pre-existing heart problems who smoke are significantly more likely to develop heart disease than people who don’t. In other words, we can say with confidence that, for many individuals, a smoking habit comes before heart disease. That is, of course, not the same as categorically proving that smoking causes heart disease – but it is a stage closer to that than merely being able to say that smoking and heart disease co-exist within many individuals.
By contrast, this is all that can be said with regard to depression and its associated ‘risk factors’ – that they co-exist within many individuals. As I’ve already mentioned, this study, because it failed to measure depression and behavioural changes more frequently, represents a wasted opportunity to have looked at whether or not an increased TV habit preceded or followed the onset of depression. However, even if the researchers had undertaken to do this, and had demonstrated that in most cases increased watching of TV preceded the onset of depression, they would not have been able to conclusively prove that watching TV causes depression.
It is possible, for example, that symptoms such as lack of energy and listlessness, before they became clinically significant enough to be classed as depression, may cause an increased desire for passive and undemanding leisure activities. In this case, it would be more accurate to describe increased TV watching as an ‘early warning sign’ for depression, rather than its cause. Certainly – and this is of course purely anecdotal evidence which taken on its own has absolutely no scientific significance – my own sensation of ‘falling into’ depression is that it begins with a gradual loss of energy, and that this eventually (or sometimes rapidly) becomes pronounced enough to justify calling it depression.
What all of this means is that, for the foreseeable future, it’s going to be very difficult to prove whether or not lifestyle factors like watching TV are the cause of mental illnesses like depression. The main reason for this difficulty is that there’s no objective test for depression – just a subjective judgement of mood and behaviour made (usually) by a doctor. Until it’s possible for science or medicine to come up with a physiological test for depression – a characteristic pattern of brain activity, perhaps, or a particular balance of substances in the bloodstream – it will never be possible to say whether a particular form of behaviour is an early symptom of underlying problems, or whether it is the cause of problems which will emerge later.
And what that means is that, while it’s very interesting to look at these questions, and we should never exclude the possibility that something truly significant will emerge from one of these studies, they are really nothing but distractions. From the perspective of people with mental illnesses, and the people who treat them, it would be far more beneficial to concentrate on symptoms, and how to relieve them, than it is causes, and how to avoid them. I’m a big supporter of scientific research for its own sake – it is always better to try and understand than it is to flounder along in ignorance – but I do think that, until science has learned a lot more about the brain and the mind than it currently knows, it’s a mistake for clinicians and patients to focus on causes and cures at the expense of symptoms and symptom management.
* – I am aware this is only a fair criticism if we’re talking about mainstream rap.