1
00:00:07,668 --> 00:00:11,309
Depression is the leading cause
of disability in the world.

2
00:00:11,308 --> 00:00:12,381
In the United States,

3
00:00:12,381 --> 00:00:15,682
close to 10% of adults 
struggle with depression.

4
00:00:15,682 --> 00:00:17,358
But because it's a mental illness,

5
00:00:17,358 --> 00:00:21,597
it can be a lot harder to understand
than, say, high cholesterol.

6
00:00:21,597 --> 00:00:25,390
One major source of confusion is
the difference between having depression

7
00:00:25,390 --> 00:00:27,963
and just feeling depressed.

8
00:00:27,963 --> 00:00:31,492
Almost everyone feels down
from time to time.

9
00:00:31,492 --> 00:00:32,710
Getting a bad grade,

10
00:00:32,710 --> 00:00:33,807
losing a job,

11
00:00:33,807 --> 00:00:34,831
having an argument,

12
00:00:34,831 --> 00:00:38,064
even a rainy day can bring on
feelings of sadness.

13
00:00:38,064 --> 00:00:39,890
Sometimes there's no trigger at all.

14
00:00:39,890 --> 00:00:42,006
It just pops up out of the blue.

15
00:00:42,006 --> 00:00:43,548
Then circumstances change,

16
00:00:43,548 --> 00:00:46,206
and those sad feelings disappear.

17
00:00:46,206 --> 00:00:48,419
Clinical depression is different.

18
00:00:48,418 --> 00:00:49,895
It's a medical disorder,

19
00:00:49,896 --> 00:00:52,777
and it won't go away 
just because you want it to.

20
00:00:52,777 --> 00:00:55,179
It lingers for at least 
two consecutive weeks,

21
00:00:55,179 --> 00:00:58,783
and significantly interferes 
with one's ability to work,

22
00:00:58,783 --> 00:00:59,590
play,

23
00:00:59,590 --> 00:01:00,996
or love.

24
00:01:00,996 --> 00:01:03,277
Depression can have a lot
of different symptoms:

25
00:01:03,277 --> 00:01:04,281
a low mood,

26
00:01:04,281 --> 00:01:06,912
loss of interest in things
you'd normally enjoy,

27
00:01:06,912 --> 00:01:08,484
changes in appetite,

28
00:01:08,484 --> 00:01:10,834
feeling worthless or excessively guilty,

29
00:01:10,834 --> 00:01:13,530
sleeping either too much or too little,

30
00:01:13,531 --> 00:01:15,362
poor concentration,

31
00:01:15,362 --> 00:01:17,197
restlessness or slowness,

32
00:01:17,197 --> 00:01:18,680
loss of energy,

33
00:01:18,680 --> 00:01:21,215
or recurrent thoughts of suicide.

34
00:01:21,215 --> 00:01:23,460
If you have at least five
of those symptoms,

35
00:01:23,460 --> 00:01:25,444
according to psychiatric guidelines,

36
00:01:25,444 --> 00:01:28,923
you qualify for a diagnosis of depression.

37
00:01:28,924 --> 00:01:31,292
And it's not just behavioral symptoms.

38
00:01:31,292 --> 00:01:35,406
Depression has physical manifestations
inside the brain.

39
00:01:35,406 --> 00:01:36,511
First of all,

40
00:01:36,510 --> 00:01:39,091
there are changes that could be seen
with the naked eye

41
00:01:39,091 --> 00:01:40,510
and X-ray vision.

42
00:01:40,510 --> 00:01:44,783
These include smaller frontal lobes
and hippocampal volumes.

43
00:01:44,783 --> 00:01:46,870
On a more microscale,

44
00:01:46,870 --> 00:01:49,350
depression is associated 
with a few things:

45
00:01:49,350 --> 00:01:53,240
the abnormal transmission or depletion
of certain neurotransmitters,

46
00:01:53,240 --> 00:01:56,870
especially serotonin, norepinephrine,
and dopamine,

47
00:01:56,870 --> 00:01:58,628
blunted circadian rhythms,

48
00:01:58,628 --> 00:02:03,337
or specific changes in the REM
and slow-wave parts of your sleep cycle,

49
00:02:03,337 --> 00:02:05,302
and hormone abnormalities,

50
00:02:05,302 --> 00:02:10,187
such as high cortisol and deregulation
of thyroid hormones.

51
00:02:10,187 --> 00:02:12,950
But neuroscientists still don't have
a complete picture

52
00:02:12,949 --> 00:02:15,100
of what causes depression.

53
00:02:15,100 --> 00:02:20,074
It seems to have to do with a complex
interaction between genes and environment,

54
00:02:20,074 --> 00:02:21,838
but we don't have a diagnostic tool

55
00:02:21,838 --> 00:02:26,111
that can accurately predict where
or when it will show up.

56
00:02:26,111 --> 00:02:28,618
And because depression symptoms
are intangible,

57
00:02:28,618 --> 00:02:32,467
it's hard to know who might look fine
but is actually struggling.

58
00:02:32,467 --> 00:02:34,954
According to the National Institute
of Mental Health,

59
00:02:34,954 --> 00:02:37,847
it takes the average person
suffering with a mental illness

60
00:02:37,847 --> 00:02:41,138
over ten years to ask for help.

61
00:02:41,138 --> 00:02:43,115
But there are very effective treatments.

62
00:02:43,115 --> 00:02:47,611
Medications and therapy complement
each other to boost brain chemicals.

63
00:02:47,610 --> 00:02:50,631
In extreme cases,
electroconvulsive therapy,

64
00:02:50,631 --> 00:02:53,552
which is like a controlled seizure
in the patient's brain,

65
00:02:53,552 --> 00:02:55,668
is also very helpful.

66
00:02:55,668 --> 00:02:56,989
Other promising treatments,

67
00:02:56,989 --> 00:02:59,621
like transcranial magnetic stimulation,

68
00:02:59,621 --> 00:03:01,799
are being investigated, too.

69
00:03:01,799 --> 00:03:04,405
So, if you know someone 
struggling with depression,

70
00:03:04,405 --> 00:03:08,776
encourage them, gently, to seek out
some of these options.

71
00:03:08,776 --> 00:03:11,175
You might even offer to help
with specific tasks,

72
00:03:11,175 --> 00:03:13,290
like looking up therapists in the area,

73
00:03:13,290 --> 00:03:16,026
or making a list of questions
to ask a doctor.

74
00:03:16,026 --> 00:03:17,689
To someone with depression,

75
00:03:17,688 --> 00:03:20,740
these first steps can seem insurmountable.

76
00:03:20,741 --> 00:03:23,026
If they feel guilty or ashamed,

77
00:03:23,026 --> 00:03:25,590
point out that depression 
is a medical condition,

78
00:03:25,590 --> 00:03:27,640
just like asthma or diabetes.

79
00:03:27,640 --> 00:03:30,274
It's not a weakness 
or a personality trait,

80
00:03:30,274 --> 00:03:33,515
and they shouldn't expect themselves
to just get over it

81
00:03:33,515 --> 00:03:36,865
anymore than they could will themselves
to get over a broken arm.

82
00:03:36,866 --> 00:03:39,461
If you haven't experienced 
depression yourself,

83
00:03:39,461 --> 00:03:42,804
avoid comparing it to times
you've felt down.

84
00:03:42,804 --> 00:03:46,977
Comparing what they're experiencing
to normal, temporary feelings of sadness

85
00:03:46,977 --> 00:03:49,598
can make them feel guilty for struggling.

86
00:03:49,598 --> 00:03:52,935
Even just talking about 
depression openly can help.

87
00:03:52,936 --> 00:03:57,314
For example, research shows that asking
someone about suicidal thoughts

88
00:03:57,314 --> 00:03:59,813
actually reduces their suicide risk.

89
00:03:59,813 --> 00:04:03,765
Open conversations about mental illness
help erode stigma

90
00:04:03,765 --> 00:04:06,501
and make it easier 
for people to ask for help.

91
00:04:06,502 --> 00:04:08,293
And the more patients seek treatment,

92
00:04:08,293 --> 00:04:10,992
the more scientists will learn
about depression,

93
00:04:10,991 --> 00:04:13,209
and the better the treatments will get.