If you’ve ever
experienced anxiety and depression — in the clinical sense, I mean — you’ll know
that they can feel really different with anxiety, you’re all ramped up and with
depression, you’re very, very down.
Yet they tend
to go together and a lot of medications, especially certain types of
antidepressants, can be used to treat both. We still don’t know a ton about how
exactly anxiety and depression work in the brain.
How antidepressants
work to treat them. But over time, psychologists have come to realize that the
two types of conditions are surprisingly similar. They may feel very different
in the moment.
But they
actually have a lot of symptoms in common, and involve some very similar
thought patterns. They might even have similar brain chemistry. So if you’re
looking to understand a little more about how anxiety and depression manifest themselves.
Whether for yourself or for someone else in your life those connections are a good
place to start.
Depression and
anxiety aren’t really specific disorders — they’re generic terms for types of
disorders. But the most common, and most closely linked, are major depressive
disorder, or MDD, and generalized anxiety disorder, or GAD.
In any given
year in the U.S., where it’s easiest to find detailed statistics, about 7% of
the population will have MDD, and about 3% will have GAD.
Lots of those
people have both: About 2/3 of people with major depression also have some kind
of anxiety disorder and about 2/3 of people with generalized anxiety disorder also
had major depression. And whether you have one or the other or both, the same
medications are often at the top of the list to help treat it — usually
antidepressants.
Unsurprisingly,
psychologists have noticed these statistics. But for a long time, we’ve thought
of generalized anxiety and major depression as very different things, and
understandably so.
Probably the
most noticeable symptom of anxiety is arousal, which in psychology is a
technical term rather than a specifically sexual thing.
It basically just
means being on high alert whether psychologically, with increased awareness, or
physically, with things like a racing heart and sweaty palms.
Arousal isn’t
part of major depression, though and there’s a key symptom of MDD that doesn’t
usually show up in generalized anxiety: low positive affect, which is the
technical term for not getting much pleasure out of life and feeling lethargic
and just kind of blah.
So there are
important differences between anxiety and depression, which is part of why they’re
still considered separate classes of disorders.
But when you
look at the other symptoms, you start to realize that major depression and generalized
anxiety have almost everything else in common.
There’s
restlessness, fatigue, irritability, problems with concentration, sleep disturbances
… the list goes on and that’s just in the official diagnostic criteria.
So for decades,
psychologists have been examining the models they use to describe anxiety and depression
in the brain to see if they point to a similar source for both types of
disorders.
They’ve come up
with lots of different ideas, as researchers do, but the most common ones tend
to center around the fight or flight response to stress.
Fight or flight
kicks in when you’re confronted with something your mind sees as a threat, and
it automatically prepares you to either fight or run away and when you think
about it, anxiety and depression are just different types of flight.
Psychologists
often characterize anxiety as a sense of helplessness, at its core, and depression
as a sense of hopelessness.
Anxiety might
feel like you’re looking for ways to fight back.
But part of
what makes it a disorder is that it’s not a short-lived feeling that’s easily
resolved once you have a plan Of course, as with all things mental health,
anxiety disorders can be deeply personal and won’t feel the same for everybody.
But clinical
anxiety does tend to be more pervasive.
The worry
sticks around and starts to take over your life because it doesn’t feel like something
you can conquer. So anxiety and depression might just be slightly different
ways of expressing the same flight response: helplessness or hopelessness and
maybe that’s part of why they so often go together.
That connection
also shows up on the biochemical side of the stress response. There are a lot
of hormones involved in this response, and their effects interact in super complex
ways that scientists still don’t fully understand. But both depressive and
anxiety disorders are closely associated with an oversensitive stress response
system.
Researchers
think that’s one reason both of these types of disorders are so much more common
in people who’ve experienced major stresses like trauma or childhood abuse.
Those stressors
could make their stress response system more sensitive. The main hormones
involved aren’t always the same, but the changes can cause some of the same
symptoms problems with sleep, for
example.
So anxiety and
depression seem to be two sides of a similar reaction to stress, in terms of
both thought processes and hormones Still, that doesn’t really explain why some
antidepressants can treat both anxiety and depression.
Because those
medications primarily affect neurotransmitters, the molecules your brain cells
use to send messages to each other. If you thought we had a lot left to learn
about how the stress response works, we know even less about what the brain
chemistry of anxiety and depression looks like, or how antidepressants help.
But if the
thought processes and physical responses that go along with these disorders aren’t
quite as different as they seem on the surface, it makes sense that the brain chemistry
would be similar, too. And that’s exactly what scientists have found.
More
specifically, lots of studies have pointed to lower levels of the
neurotransmitter known as serotonin as a major factor in both anxiety and
depression.
Researchers
have even identified some more specific cellular receptors that seem to be
involved in both. There’s also some evidence that the way the brain handles
another neurotransmitter, norepinephrine, can be similar in both anxiety and
depression.
Since most
antidepressants work by increasing serotonin levels, and some of them also
affect norepinephrine that could explain why they’re so helpful for both
anxiety and depression. Although again, there’s a lot we don’t know about their
exact mechanisms.
Ultimately,
there’s no denying that in the moment, anxiety and depression can seem like
very different feelings and if someone has both types of disorders well, it’s easy to see how that could feel
overwhelming.
Like, it’s hard
enough treating generalized anxiety or major depression on their own and it’s
true that it is often harder to treat these conditions when someone has both. But
maybe not twice as hard. After all, anxiety and depressive disorders have a lot
in common, from their symptoms to the basic brain chemistry behind them to some
of the treatments that can help.
The fact that
they often go together can be really tough. But understanding more about why
that is has also pointed us toward better treatments and more effective therapies that really can
help.
