Depression and Anxiety: Two in One?

Depression and anxiety tend to show up side by side. Most of us have felt one or the other, or both, at some stretch of our lives, simply because living can get hard and overwhelming. There's an old line about bad things happening to good people, and it captures how ordinary circumstances can hand us something we didn't ask for. Losing a job. Losing a spouse or a relative. Money trouble, a divorce, a marriage or relationship coming apart. Any of these can tip a person into stress, grief, worry, or a low that won't lift. The two conditions differ in real ways, yet they share a surprising amount of ground.

On the depression side, the signs run long. You might feel tearful for no clear reason, or find yourself crying often. Sadness settles in and stays, usually two weeks or more. Things you used to enjoy, including time with friends, stop being fun. Life can start to seem hopeless, and you can feel helpless inside it. Irritability lingers; some people get snappy or have angry outbursts. Shame, guilt, and a sense of worthlessness creep in. Concentration drops and decisions feel impossible. Appetite shifts, with weight climbing or falling. Sleep goes sideways, whether that means too much of it, too little, trouble drifting off, waking before dawn, or sleeping most of the day and still feeling drained. In its darkest form, depression brings thoughts of suicide, plans, or attempts, and sometimes a new or heavier reliance on alcohol or drugs.

Anxiety carries its own cluster. There's the feeling of panic or dread, sometimes with a reason and sometimes without. Breath gets short and hard to catch, and the heart races past where it should. Palpitations can mimic a heart attack. Hands and feet go numb or tingle, as if a current were running through your limbs. The stomach turns, with nausea, vomiting, or pain. Muscles tighten, and the ache shows up in the neck, arms, and shoulders.

Put the two lists next to each other and the overlap jumps out. It's common for a person with an anxiety disorder to also carry depression, and the reverse holds too. Nearly half of those diagnosed with depression also meet the criteria for an anxiety disorder. Charles Goodstein, MD, a professor of psychiatry at New York University School of Medicine who keeps a clinical practice in Tenafly, N.J., puts it bluntly: people very often have both at once. He notes that a depressed patient without some anxiety is hard to find, and someone anxious without a trace of depression is just as rare.

The two also feed each other. Anxiety can set off depression, depression can set off anxiety, and the pair affects the brain through similar channels. Both have been tied to a drop in serotonin, the neurotransmitter that steadies mood and a person's sense of well being. When serotonin runs low, you can get depressive symptoms, anxious symptoms, or the two together. Research has also pointed to a shift in the brain's stress response, run largely by the amygdala, where studies have repeatedly found heightened reactivity.

Still, they aren't the same thing, and the differences matter for telling them apart. Someone with depression feels flattened, sad, drained of energy, and the weight tends to stay put, running continuously for two weeks or longer. Anxiety moves differently. A person can feel keyed up all day, or go through stretches of chronic stress, yet the feeling may ease at points, vanish for a day or several, then come back. Anxiety can also arrive with panic attacks, the kind where you're convinced you're having a heart attack or losing your mind, and those attacks can breed more anxiety and even phobias. Depression doesn't do that.

So the symptoms overlap, but these remain two distinct disorders, each with its own roots and its own emotional and behavioral marks, even as one can trigger the other. Both leave a deep mark on a person's life, which is why professional help is worth seeking for either, and a clinician can treat them at the same time. - Kim B.