Is Depression Really on The Rise?
It’s an idea repeated so often that it’s now taken for fact – depression is on the rise.
If true, modern society has messed up.
In 1985, 10% of people had no one to discuss important matters with. By 2004, that number had grown to 25% – one out of every four people! (1)
We’re spending less time with other people, eating worse food, and getting less exercise, sunlight, and sleep.
Surely the rate of depression has gone up.
My father disagrees.
Normally that wouldn’t mean anything to me – he believes lots of crazy things. But he’s a psychiatrist.
Psychiatrists are the ones who invented the scientific study of mental dysfunction.
Psychiatry has insights to offer.
Is the idea that the rise of depression is more media sensationalization than hard journalism one of them?
The first is its squeamishness. For example, for most people an antidepressant is not that much more effective than a placebo. But electroconvulsive therapy (ECT) is faster, safer, and more effective than antidepressents. And yet ECT is recommended only to those patients who’ve tried everything else first. Why? Squeamishness. Yes, memory loss is a serious concern. But for many who’ve lost their will to live and spend hours a day crying, that’s a risk they’re willing to take.
The second is its focus on dysfunction, although this is a wider cultural problem. Most of healthcare is focused on treatment rather than prevention – on prescribing medication rather than encouraging healthy eating. But let’s go beyond prevention.
Insurance covers psychotherapy but not Happier Human coaching; it covers physical therapy but not gym membership. We’ve set the bar too low. Positive psychology is a step in the right direction, but psychiatry could help.
Most people think anti-depressants are okay to move someone from sad to slightly happy, but immoral to move someone from slightly happy to happier. I have no such objection. My only concern is side-effects. Almost no research is done into using drugs to safely making people happier. I’m not talking about snorting cocaine or becoming a pothead – even a drug as safe as marijuana has the side-effect of making some people less productive (and maybe increasing the risk of schizophrenia, although that’s not clear).
There exist some drugs which evidence suggests may be safe for most people and which even after just a few doses can have long lasting beneficial effects. But no research gets done because doing drugs if you’re not sick makes you a lazy hippie. Which is a crazy thing to believe, considering most people consume caffeine every day.
Millions Diagnosed With Depression Every Year
If we count and compare the number of people being diagnosed with depression, we should have the answer.
Number of People Diagnosed With Depression Each Year
For every person who took an anti-depressant in 1987, there are now more than five.
Depression is not merely ‘on the rise’ – it’s an epidemic, with an estimated cost of nearly $100 billion a year. (5)
But that increase is deceptive. Yes, there are more people getting diagnosed with depression, but there are three explanations for that.
1) Depression has become more common.
2) Anti-depressants have gotten better. Anti-depressants sometimes cause fatigue, heart arrhythmias or cognitive impairment, but these side-effects are rare. In the 1980s they were common. (6)
3) Seeing a shrink is no longer taboo. I’m not going to tell someone on a first date, but I don’t hide the fact that I had trouble with depression growing up. According to the NAMCS survey, less than 20% of people with depression in 1987 sought treatment.
It’s obvious that there’s an obesity epidemic. You can’t pretend to be fit if you’re actually 750 pounds.
The same can’t said of depression – it’s possible to cover up sadness with a fake smile.
What portion of the increase is due to an increased incidence of depression? We need more data to answer that question.
We need to know how many people were depressed, not how many people were diagnosed with depression.
Have You Ever Been Depressed?
Ask a large number of folks who are 25 if they’ve ever had any symptoms of depression. Then ask the same of a large number of folks who are 50. Compare.
But the folks who are 50 have had twice as many opportunities to develop depression. Not a problem.
One study which came out in 2005 adjusted for that.
Lifetime Risk of Depression
According to them, 7.3% of those in their 20s will experience clinical depression at least once during their life, if they haven’t already.(7)
That’s a large number – almost three times as large as the number for folks in their 50s.
Not as large as the 450% increase suggested by the first set of data, but still alarming.
And yet, we still need more data.
A number of scientists claim that these results are getting skewed by something called recall bias.
It isn’t that folks in their 50s lived a happier, healthier life. They’ve just forgotten those times that they were depressed.
I’m not talking about dementia, although it does annoy me when my grandfather thinks I’m a girl.
Most people come down with depression when they’re young.
So yes, that 50 year old will be less likely to report having experienced any symptoms of depression. Those two months of lethargy and loss of appetite he experienced after his first girlfriend left him for an older man have been forgotten. That was 41 years ago! Now he’s that older man.
In one study kids were interviewed at ages 15, 16, 18, and 21 and asked about their mental health. Then at age 25 they were asked,
Looking back over your whole life before you were 21, did you ever have a period of at least two weeks when you (a) felt sad, blue or depressed nearly every day? (b) lost interest in most things like work, hobbies or things you usually enjoy?
56% of those who had met the criteria for depression prior to age 21 answered no to that question. (8)
Within just five to ten years, the majority of kids had forgotten about or become too ashamed to admit to their prior experience with depression. Now imagine the same experiment being done again, but from age 15 to 50. What percent of those 50 year olds would remember?
This is great from a mental health perspective – dwelling on unhappiness in the past is no good. But from a science trying to understand what’s going on perspective… it seems like we’ll once again need more data.
Don’t We Have Historical Records?
An accurate analysis wouldn’t rely on a person’s memory – it would rely on historical records.
It would ask a random sample of people in 1990 if they had any symptoms of depression, and then ask the same of a random sample of people ten years later. If more people report having symptoms of depression, we can infer that the rate of depression has gone up.
One study did exactly that, and found no difference. Folks in 1990 were as likely to report depression as folks in 2000. (9)
But a half dozen other studies found the opposite thing, with folks two to three times more likely to report symptoms than a few decades ago. (10)
I asked my dad and he said,
Amit, there’s something methodologically flawed with those six studies, ignore them.
At first I thought he was being ridiculous – simply wishing away evidence which contradicts his opinion. But after doing some more research I realized he might be right. Each of those half-dozen studies had either one or both of the following problems.
1) Response bias – in the 1960s folks were more likely to lie. They were more embarrassed to admit, “yes, after my wife died there was a period where I lost all motivation to live.”
2) Different surveys taken at almost the same time in the same place see different results. In one survey taken in Canada in 2001, the prevalence of depression came out to be 4.8%. In another taken in 2002 also in Canada, the rate came out to 7.4%. (11)
The incidence of depression didn’t increase by 60% in one year. Well, 2002 is the same year that survey came out showing most American teenagers think Canada is an American state. That could be kind of depressing.
But the more likely explanation is that it’s the change in survey which caused the increase, not an actual rise in the rate of depression.
So, one more time… we need more data.
Stalk Me, Please!
To avoid the problem that different surveys give different results, ask the same questions every time.
To avoid the problem that different sub-groups report different rates of depression, follow the same group of people for a few years or ask questions to a large number of people representative of the entire population.
To avoid recall bias, ask folks questions which gauge their current mental state, not their mental state 20 years ago.
Then repeat, year after year after year.
To ensure participants respond honestly there’s little that can be done. But willingness to admit to symptoms of depression is something that changes slowly.
What do we get once we take this all into account?
In one study respondents in 2007 were six times more likely to be depressed or anxious than those in 1938. But how can those results be trusted? Folks in 1938 were more likely to hide symptoms of depression.
The survey used asked over 500 questions, many of which were used to innocuously gauge how likely the person was to lie in order to give more desirable answers. After controlling for the increasing tendency to be honest about one’s problems, the increase fell to 300% – not so great as 500%, but still large. (14)
In another study of 42,000 Americans, the prevalence of depression increased from 3.3% in 1991 to 7% in 2002. (13)
In one longitudinal study of 4,750 Danes, 2% of the sample reported symptoms matching clinical depression in 2,000. Six years later that number had increased to 4.9%. (12)
The exact number varies from study to study, so it’s unclear by how much the rate of depression has increased. But that depression has become more common? That seems certain.
Not once but three times did I discard data because it might not be reliable.
The situation is insane. Not that I had to discard so much data. That regardless of what data we look at, the picture seems to be the same – depression has become more common.
The whole point of economic growth is to improve one’s quality of life. It seems that for many, mental health was left behind.