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Thomas Insel: Toward a new understanding of mental illness

トーマス・インセル: 精神疾患の新たな理解に向けて

January 18, 2013

今日、早期発見や早期加療のおかげで、数十年前と比べ心臓病による死亡は63%も減少している。「うつ病や統合失調症患者にも、同じ事ができないだろうか?」アメリカ国立精神衛生研究所の所長を務める、トーマス・インセルはそう考えた。この新たな研究への第一歩は、「『精神病』と考えるのを止め、『脳の障害』だと認識する」という重要な見直しだった。

Thomas Insel - Neuroscientist and psychiatrist
The Director of the National Institute of Mental Health, Thomas Insel supports research that will help us understand, treat and even prevent mental disorders. Full bio

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Double-click the English subtitles below to play the video.
So let's start with some good news,
まず良いニュースから始めましょう
00:12
and the good news has to do with what do we know
良いニュースと言うのは
00:15
based on biomedical research
生物医学研究によって
00:17
that actually has changed the outcomes
多くの重症疾患の治療成果に
変化が表れている事を ご存知でしょうか
00:19
for many very serious diseases?
多くの重症疾患の治療成果に
変化が表れている事を ご存知でしょうか
00:23
Let's start with leukemia,
白血病から見ていきましょう
00:26
acute lymphoblastic leukemia, ALL,
急性リンパ性白血病(ALL)は
00:28
the most common cancer of children.
小児がんで最も多く
00:31
When I was a student,
私が学生の頃の死亡率は
約95%でした
00:33
the mortality rate was about 95 percent.
私が学生の頃の死亡率は
約95%でした
00:35
Today, some 25, 30 years later, we're talking about
25年 30年が経った今日
00:39
a mortality rate that's reduced by 85 percent.
死亡率は85%も下がりました
00:42
Six thousand children each year
以前なら助からなかった
6000人もの子ども達が
00:46
who would have previously died of this disease are cured.
毎年 助かっています
00:48
If you want the really big numbers,
より大きな数値は
00:53
look at these numbers for heart disease.
心臓病に見られます
00:54
Heart disease used to be the biggest killer,
心臓病はかつて最大の死因でした
00:57
particularly for men in their 40s.
特に40代の男性です
00:59
Today, we've seen a 63-percent reduction in mortality
今日 心臓病による死亡率は
63%も低下しています
01:00
from heart disease --
今日 心臓病による死亡率は
63%も低下しています
01:04
remarkably, 1.1 million deaths averted every year.
実に 年間110万人もが
死なずに済んでいるのです
01:06
AIDS, incredibly, has just been named,
エイズは なんとこの数カ月で
01:11
in the past month, a chronic disease,
慢性疾患と呼ばれるようになりました
01:14
meaning that a 20-year-old who becomes infected with HIV
というのも
HIVに感染した20歳の人は
01:16
is expected not to live weeks, months, or a couple of years,
数週間 数か月
数年も生きられない
01:19
as we said only a decade ago,
わずか10年前までは
そう言われていたのです
01:23
but is thought to live decades,
しかし今は
何十年も生きられると考えられています
01:25
probably to die in his '60s or '70s from other causes altogether.
恐らく60代 70代が寿命で
死因は合併症によるものでしょう
01:28
These are just remarkable, remarkable changes
いくつかの主な死因の見通しにおいて
01:32
in the outlook for some of the biggest killers.
これらの変化は本当に驚くべきものです
01:35
And one in particular
とりわけ
01:38
that you probably wouldn't know about, stroke,
皆さんはあまり
ご存じないかもしれませんが
01:40
which has been, along with heart disease,
脳卒中は 心臓病と並び
01:42
one of the biggest killers in this country,
長い間 国内最大の死因のひとつでした
01:43
is a disease in which now we know
今では
01:46
that if you can get people into the emergency room
発症から3時間以内に
緊急治療室で処置を受ければ
01:47
within three hours of the onset,
発症から3時間以内に
緊急治療室で処置を受ければ
01:50
some 30 percent of them will be able to leave the hospital
患者の30%ほどが 何の後遺症もなく
01:52
without any disability whatsoever.
退院できます
01:55
Remarkable stories,
驚くべきストーリー
01:58
good-news stories,
明るいニュースです
02:00
all of which boil down to understanding
つまるところ それらは全て
02:02
something about the diseases that has allowed us
ある病気を早期発見
02:06
to detect early and intervene early.
早期治療ができたという話なのです
02:09
Early detection, early intervention,
早期発見 早期加療
02:12
that's the story for these successes.
それこそが これらの成功の種なのです
02:14
Unfortunately, the news is not all good.
残念ながら
良いニュースばかりではありません
02:17
Let's talk about one other story
もうひとつ お話しましょう
02:20
which has to do with suicide.
自殺についてです
02:23
Now this is, of course, not a disease, per se.
もちろん 自殺自体は
病気とは言えませんね
02:24
It's a condition, or it's a situation
死に至ってしまう
状態や状況の事です
02:27
that leads to mortality.
死に至ってしまう
状態や状況の事です
02:30
What you may not realize is just how prevalent it is.
どれほど蔓延しているか
ご存じでない方が多いかもしれません
02:32
There are 38,000 suicides each year in the United States.
毎年 アメリカでは
3万8000人の自殺者が出ています
02:35
That means one about every 15 minutes.
約15分に1人の割合です
02:39
Third most common cause of death amongst people
15歳~25歳の若者の間で
02:42
between the ages of 15 and 25.
3番目に最も多い死因です
02:45
It's kind of an extraordinary story when you realize
考えてみれば 衝撃的な事実です
02:47
that this is twice as common as homicide
殺人事件の2倍も多く
02:50
and actually more common as a source of death
さらに この国の主な死亡原因である
02:52
than traffic fatalities in this country.
交通事故死よりも多いのです
02:55
Now, when we talk about suicide,
さて 自殺には
02:58
there is also a medical contribution here,
医学的要因があります
03:01
because 90 percent of suicides
自殺の90%が
03:04
are related to a mental illness:
精神疾患と関連があるからです
03:06
depression, bipolar disorder, schizophrenia,
うつ病 双極性障害 統合失調症
03:08
anorexia, borderline personality. There's a long list
拒食症 境界性人格障害
03:11
of disorders that contribute,
要因は沢山あります
03:14
and as I mentioned before, often early in life.
しかも多くは人生の早い段階でのことです
03:16
But it's not just the mortality from these disorders.
しかし問題は
障害による死亡率だけではなく
03:20
It's also morbidity.
疾病率です
03:23
If you look at disability,
障害について見てみると
03:25
as measured by the World Health Organization
これらの数値は
世界保健機関(WHO)が
03:27
with something they call the Disability Adjusted Life Years,
障害調整生命年(DALYs) という
03:30
it's kind of a metric that nobody would think of
専門的な測定法を使用して
算出されています
03:33
except an economist,
経済学者 または―
03:35
except it's one way of trying to capture what is lost
医学的原因による障害により
03:36
in terms of disability from medical causes,
失われた年数を導く目的以外では
使われない指標です
03:40
and as you can see, virtually 30 percent
ご覧の通り 実に 30%もの
身体障害の医学的要因は
03:43
of all disability from all medical causes
ご覧の通り 実に 30%もの
身体障害の医学的要因は
03:46
can be attributed to mental disorders,
精神障害や
03:48
neuropsychiatric syndromes.
精神医学的症候群なのです
03:51
You're probably thinking that doesn't make any sense.
「何を言っているんだ?」
そう思うでしょう
03:53
I mean, cancer seems far more serious.
がんや心臓病の方が
03:55
Heart disease seems far more serious.
遥かに深刻そうですが
03:58
But you can see actually they are further down this list,
しかしこれらはリストのずっと下位にあり
04:01
and that's because we're talking here about disability.
なぜなら これは身体障害について
ついてだからです
04:04
What drives the disability for these disorders
何が 統合失失調症や
双極性障害や うつ病などの
04:06
like schizophrenia and bipolar and depression?
精神病を引き起こすのでしょうか
04:09
Why are they number one here?
なぜそれらが最も多いのでしょう
04:13
Well, there are probably three reasons.
恐らく 理由は3つ
04:16
One is that they're highly prevalent.
第1に 非常に蔓延していると言う事
04:18
About one in five people will suffer from one of these disorders
約5人に1人が 人生のどこかで
04:20
in the course of their lifetime.
いずれかの病気に苦しむでしょう
04:23
A second, of course, is that, for some people,
第2に そのうちの何人かは
04:25
these become truly disabling,
本当に何もできなくなってしまう人もいます
04:28
and it's about four to five percent, perhaps one in 20.
約4~5%
恐らく 20人に1人の割合です
04:29
But what really drives these numbers, this high morbidity,
しかし 何が1番
これほどの高い疾病率や
04:32
and to some extent the high mortality,
更には 高い死亡率を
引き起こしているのかというと
04:37
is the fact that these start very early in life.
それはこれらが
人生の早い段階で始まるからなのです
04:39
Fifty percent will have onset by age 14,
50%が 14歳までに
04:43
75 percent by age 24,
75%が 24歳までに発症します
04:46
a picture that is very different than what one would see
全く事情が別だ と考えてください
04:49
if you're talking about cancer or heart disease,
例えば がんや心臓病
04:53
diabetes, hypertension -- most of the major illnesses
糖尿病 高血圧等の重篤な病気は
04:55
that we think about as being sources of morbidity and mortality.
疾病や 死因となりうる
多くの疾患とは 全く違います
04:58
These are, indeed, the chronic disorders of young people.
まさに若い世代の慢性疾患なんです
05:03
Now, I started by telling you that there were some good-news stories.
さて 私は初めに
良いニュースをお伝えしました
05:09
This is obviously not one of them.
今の話は全く逆です
05:12
This is the part of it that is perhaps most difficult,
恐らくは最も難しい部分であり
05:13
and in a sense this is a kind of confession for me.
ある意味
わたしの懺悔でもあります
05:16
My job is to actually make sure that we make progress
私の仕事は
それら障害の理解や対処法に
05:19
on all of these disorders.
進展をもたらす事です
05:24
I work for the federal government.
私は政府に仕えていますが
05:26
Actually, I work for you. You pay my salary.
正確には あなた方に です
05:28
And maybe at this point, when you know what I do,
この時点で あなた達は
私がしている事
05:30
or maybe what I've failed to do,
私が成し得なかった事を知り
05:32
you'll think that I probably ought to be fired,
クビにすべきだと 思うかもしれません
05:35
and I could certainly understand that.
そう思われても仕方ないんです
05:37
But what I want to suggest, and the reason I'm here
しかし 今から言う提案を聞いてください
05:39
is to tell you that I think we're about to be
今日ここに来たのは
そのためです
05:41
in a very different world as we think about these illnesses.
私達は これらの病気において
全く違う概念を持つようになります
05:44
What I've been talking to you about so far is mental disorders,
ここまで私は
精神障害について話しました
05:49
diseases of the mind.
「心の病」についてです
05:52
That's actually becoming a rather unpopular term these days,
実際にはこの言い方は
最近あまり使われなくなっています
05:54
and people feel that, for whatever reason,
理由は様々ですが
05:57
it's politically better to use the term behavioral disorders
「行動障害」の方が公正な表現であり
06:00
and to talk about these as disorders of behavior.
行動の障害を
「心の病」を としています
06:03
Fair enough. They are disorders of behavior,
いいでしょう
それらは「行動障害」であり
06:07
and they are disorders of the mind.
「心の病」でもあります
06:09
But what I want to suggest to you
しかし ここで私が伝えたいのは
06:11
is that both of those terms,
そのどちらの用語も
06:14
which have been in play for a century or more,
1世紀以上も前から存在し
06:15
are actually now impediments to progress,
それが進展の妨げとなっています
06:18
that what we need conceptually to make progress here
ここで私達がやるべき事は
06:21
is to rethink these disorders as brain disorders.
これらを
「脳の障害」だと見直す事です
06:25
Now, for some of you, you're going to say,
さて 中にはこう言う人がいるでしょう
06:31
"Oh my goodness, here we go again.
「あぁ またか!」
06:33
We're going to hear about a biochemical imbalance
「生化学の不均衡だの
06:35
or we're going to hear about drugs
薬物だの
06:37
or we're going to hear about some very simplistic notion
主観的な体験を例にした
06:39
that will take our subjective experience
単純な見解が また始まった」
06:44
and turn it into molecules, or maybe into some sort of
「次に分子の話になって
06:47
very flat, unidimensional understanding
うつ病や統合失調症がどんなものか
06:53
of what it is to have depression or schizophrenia.
漠然とした話を始めるだろう」 と
06:56
When we talk about the brain, it is anything but
脳の話は
決して表面的でもなければ
07:00
unidimensional or simplistic or reductionistic.
単純な 還元主義的な話でもありません
07:05
It depends, of course, on what scale
もちろん 話の規模や
07:08
or what scope you want to think about,
その範囲によっても違ってきますが
07:11
but this is an organ of surreal complexity,
しかし脳は
実に複雑な臓器で
07:13
and we are just beginning to understand
その研究方法でさえ
07:20
how to even study it, whether you're thinking about
やっと 分かり始めてきたのです
07:23
the 100 billion neurons that are in the cortex
大脳皮質には1000億の神経細胞があり
07:25
or the 100 trillion synapses
また100兆のシナプスで
07:28
that make up all the connections.
脳の機能を結合させています
07:30
We have just begun to try to figure out
我々は 探り始めたばかりです
07:32
how do we take this very complex machine
どうやって
この複雑な情報処理器官を
07:36
that does extraordinary kinds of information processing
解明すればいいのか
そして―
07:39
and use our own minds to understand
我々の「心」を支えている
この複雑な脳を
07:42
this very complex brain that supports our own minds.
どう「心」で理解できるのか
07:45
It's actually a kind of cruel trick of evolution
これはある種の
進化における残酷ないたずらです
07:48
that we simply don't have a brain
自分たちの脳を解明する頭脳を
07:51
that seems to be wired well enough to understand itself.
我々は持っていないんです
07:55
In a sense, it actually makes you feel that
ある意味
こう感じる事があるでしょう
07:58
when you're in the safe zone of studying behavior or cognition,
実際に観察のできる 行動や認知など
08:00
something you can observe,
安全な領域の研究をしている
08:03
that in a way feels more simplistic and reductionistic
それは
今我々が探り始めた
08:04
than trying to engage this very complex, mysterious organ
この非常に複雑で
不可解な器官と比べると
08:07
that we're beginning to try to understand.
もっと単純で
還元主義的だと感じるでしょう
08:12
Now, already in the case of the brain disorders
さて 先程から話している
「脳の障害」ですが
08:15
that I've been talking to you about,
うつ病や 強迫性障害
08:18
depression, obsessive compulsive disorder,
PTSD 等に関して言えば
私達は―
08:20
post-traumatic stress disorder,
PTSD 等に関して言えば
私達は―
08:22
while we don't have an in-depth understanding
脳内でどんな異常な処理が
行われているのか
08:24
of how they are abnormally processed
病気にかかっている間
脳がどう機能しているのか
08:27
or what the brain is doing in these illnesses,
深く理解していない一方で
08:31
we have been able to already identify
私達はすでに
これらの障害のある人の脳の中で
08:33
some of the connectional differences, or some of the ways
何らかの異なる結合が起きていたり
08:36
in which the circuitry is different
あるいは異なる回路を持っている
という事が
08:39
for people who have these disorders.
分かっています
08:41
We call this the human connectome,
これを
ヒト・コネクト-ムと呼んでいます
08:43
and you can think about the connectome
コネクト-ムとは
脳の神経回路図だと思ってください
08:45
sort of as the wiring diagram of the brain.
コネクト-ムとは
脳の神経回路図だと思ってください
08:47
You'll hear more about this in a few minutes.
これについては また説明します
08:49
The important piece here is that as you begin to look
重要なのは
これら「障害」がある人を見た時に
08:51
at people who have these disorders, the one in five of us
私達の5人に1人が
08:54
who struggle in some way,
何らかの症状に悩んでいるのです
08:58
you find that there's a lot of variation
脳にたくさんの種類の回路があるように
09:00
in the way that the brain is wired,
その症状は様々です
09:02
but there are some predictable patterns, and those patterns
しかし予測できる特徴があり
09:05
are risk factors for developing one of these disorders.
それがいずれかの「障害」の
危険因子です
09:08
It's a little different than the way we think about brain disorders
大脳皮質の一部がダメになる
09:12
like Huntington's or Parkinson's or Alzheimer's disease
ハンチントン病やパーキンソン病
アルツハイマーとは
09:15
where you have a bombed-out part of your cortex.
少し考え方が違います
09:18
Here we're talking about traffic jams, or sometimes detours,
まるで 交通渋滞のような物です
あるいは遠回りだったり
09:20
or sometimes problems with just the way that things are connected
脳の回路に問題がある場合や
機能の仕方の問題
09:23
and the way that the brain functions.
脳の回路に問題がある場合や
機能の仕方の問題
09:26
You could, if you want, compare this to,
こう比較しても良いです
09:27
on the one hand, a myocardial infarction, a heart attack,
心筋梗塞 あるいは心臓発作の様に
細胞が死ぬ病気に対し
09:30
where you have dead tissue in the heart,
心筋梗塞 あるいは心臓発作の様に
細胞が死ぬ病気に対し
09:33
versus an arrhythmia, where the organ simply isn't functioning
臓器内で伝達障害が起きていて
単に―
09:35
because of the communication problems within it.
機能していないが為に起こる不整脈
09:39
Either one would kill you; in only one of them
どちらが致命的で
09:41
will you find a major lesion.
重い障害だと考えるでしょうか
09:43
As we think about this, probably it's better to actually go
もう少し深く 掘り下げてみましょう
09:46
a little deeper into one particular disorder, and that would be schizophrenia,
統合失調症という「障害」を例にとってみます
09:49
because I think that's a good case
統合失調症は
09:52
for helping to understand why thinking of this as a brain disorder matters.
「脳の障害」だと考える重要性を
示しやすいのです
09:54
These are scans from Judy Rapoport and her colleagues
これらのスキャンは
ジュディ・ラパポートとそのチームが
09:57
at the National Institute of Mental Health
米国国立精神衛生研究所で撮ったものです
10:01
in which they studied children with very early onset schizophrenia,
早期発症型の統合失調症を患った
子どもを研究しました
10:03
and you can see already in the top
上の脳のスキャンを見ると
10:07
there's areas that are red or orange, yellow,
赤 オレンジ 黄色で示された部分がありますね
10:09
are places where there's less gray matter,
これは灰白質の不足を示しています
10:11
and as they followed them over five years,
彼らを5年にわたって研究し
10:13
comparing them to age match controls,
同年代の対照群と比較し続けました
10:15
you can see that, particularly in areas like
ご覧の通り 特に―
10:17
the dorsolateral prefrontal cortex
背外側前頭前皮質や
10:19
or the superior temporal gyrus, there's a profound loss of gray matter.
上側頭回等の部分の
灰白質が大幅に減少しています
10:21
And it's important, if you try to model this,
ここからが大事です
10:26
you can think about normal development
通常の成長過程では
10:27
as a loss of cortical mass, loss of cortical gray matter,
皮質量や皮質灰白質が
減少する事が分かるでしょう
10:29
and what's happening in schizophrenia is that you overshoot that mark,
統合失調症ではどうかというと
過剰に減少しています
10:32
and at some point, when you overshoot,
そしてある時点で
10:36
you cross a threshold, and it's that threshold
閾値を越えてしまうんです
10:38
where we say, this is a person who has this disease,
病気である事に気付くのは
その時です
10:41
because they have the behavioral symptoms
症状が行動に表れるからです
10:44
of hallucinations and delusions.
幻覚や妄想と言った物です
10:46
That's something we can observe.
目で見て分かる症状です
10:49
But look at this closely and you can see that actually they've crossed a different threshold.
しかし よく見ると
彼らはもう1つの閾値を超えていますね
10:50
They've crossed a brain threshold much earlier,
もっと早い段階で
脳の閾値に 踏み込んでいます
10:56
that perhaps not at age 22 or 20,
恐らく 22歳 20歳にも満たない
10:59
but even by age 15 or 16 you can begin to see
15歳 16歳頃までに
11:02
the trajectory for development is quite different
発達の課程が全く違う事に
気付き始めます
11:05
at the level of the brain, not at the level of behavior.
それは脳に見られる事で
行動には表れません
11:07
Why does this matter? Well first because,
なぜこれが重要か
まず―
11:10
for brain disorders, behavior is the last thing to change.
脳の障害において
行動に変化が表れるのは最終段階なのです
11:13
We know that for Alzheimer's, for Parkinson's, for Huntington's.
アルツハイマーやパーキンソン病
ハンチントン病は
11:16
There are changes in the brain a decade or more
症状が行動に表れる 10年以上前に
脳に変化が表れるんです
11:19
before you see the first signs of a behavioral change.
症状が行動に表れる 10年以上前に
脳に変化が表れるんです
11:21
The tools that we have now allow us to detect
現在 技術によって私達は
11:26
these brain changes much earlier, long before the symptoms emerge.
より早く 症状が表れる前に
脳の変化を突き止める事ができます
11:29
But most important, go back to where we started.
しかしもっと大事な事があります
最初の話に戻りましょう
11:33
The good-news stories in medicine
医療における良いニュースは
11:37
are early detection, early intervention.
早期発見や早期治療です
11:40
If we waited until the heart attack,
心臓発作が起きるまで何もしなければ
11:43
we would be sacrificing 1.1 million lives
私達は
毎年この国の110万人の命を
11:47
every year in this country to heart disease.
犠牲にしてしまうのです
11:51
That is precisely what we do today
それが今日の現状です
11:53
when we decide that everybody with one of these brain disorders,
脳の障害や 回路の異常がある人は
11:55
brain circuit disorders, has a behavioral disorder.
行動障害があるのだと
決めつけています
12:00
We wait until the behavior becomes manifest.
症状が表れるまで
待っていては遅いのです
12:03
That's not early detection. That's not early intervention.
それでは早期発見にも
早期治療にもなりません
12:06
Now to be clear, we're not quite ready to do this.
確かに 準備は整っていません
12:11
We don't have all the facts. We don't actually even know
全てが解明できたのではなく
12:13
what the tools will be,
どんな手段を用いるかも
12:16
nor what to precisely look for in every case to be able
全ての病気に対して
行動障害が現れる前に
12:18
to get there before the behavior emerges as different.
厳密に何を診れば良いのかも
分かっていません
12:23
But this tells us how we need to think about it,
しかし この事は
病気についてどう考えるか
12:27
and where we need to go.
どこに向かえばいいのか
示してくれています
12:30
Are we going to be there soon?
ゴールは目前でしょうか
12:31
I think that this is something that will happen
恐らく そこに到達するには
12:32
over the course of the next few years, but I'd like to finish
まだ数年かかるでしょうが
12:35
with a quote about trying to predict how this will happen
この行く末を予測する
ある言葉を引用して終わります
12:38
by somebody who's thought a lot about changes
考え方や
テクノロジーの分野における
12:40
in concepts and changes in technology.
変革について
熟考を重ねた人物です
12:43
"We always overestimate the change that will occur
「我々はいつも
この2年間に起きるであろう変化を
12:45
in the next two years and underestimate
過大評価する
そして
12:47
the change that will occur in the next 10." -- Bill Gates.
この先10年間に起きるであろう変化を
過小評価する」 ―ビル・ゲイツ
12:50
Thanks very much.
ありがとうございました
12:54
(Applause)
(拍手)
12:55
Translator:Yukiho Nishibayashi
Reviewer:Misaki Sato

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Thomas Insel - Neuroscientist and psychiatrist
The Director of the National Institute of Mental Health, Thomas Insel supports research that will help us understand, treat and even prevent mental disorders.

Why you should listen

Thomas Insel has seen many advances in the understanding of mental disorders since becoming the Director of the National Institute of Mental Health (NIMH) in 2002. During his tenure, major breakthroughs have been made in the areas of practical clinical trials, autism research and the role of genetics in mental illnesses.

Prior to his appointment at the NIMH, Insel was a professor of psychiatry at Emory University, studying the neurobiology of complex social behaviors. While there, he was the founding director of the NSF Center for Behavioral Neuroscience and director of the NIH-funded Center for Autism Research. He has published over 250 scientific articles and four books and has served on numerous academic, scientific, and professional committees and boards. He is a member of the Institute of Medicine, a fellow of the American College of Neuropsychopharmacology, and a recipient of the Outstanding Service Award from the U.S. Public Health Service and the 2010 La Fondation IPSEN Neuronal Plasticity Prize. 

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