Depression is one of the most recognized psychological disorders. It’s certainly common. A 2014 survey found that 6.6 percent of American adults or 15.7 million suffered from a major depressive episode within the past 12 months, said Sandra Hamilton, Ph.D, a psychologist who specializes in treating depression, anxiety and relationship issues. With something so prevalent, many of us may assume we know what it is.

But assumptions can quickly turn to misconceptions. Misconceptions about what depression looks and feels like. Misconceptions about whether people really want to get better. Misconceptions about the seriousness of depression. Which is important because depression is serious. It affects a person’s entire being. It affects their entire life.

“I feel like I’m walking underwater.” “There is a pane of glass between me and everyone else.” “Everything seems like it is going in slow motion.” These are some of the descriptions Hamilton’s clients have used for their depression.

Colleen Mullen’s clients have described depression as a “black hole.” Some clients talk about feeling like they’re suffocating and can’t breathe. Others say they feel nothing at all. It’s not uncommon for individuals to say they feel numb. Or people feel the complete opposite: They’re “caught in a vortex of negative emotions they can’t pull themselves out of.”

“I remember one client describing the onset of depression like the beginning of a roller coaster: It slowly creeps ahead and you can see and feel the fall coming, but you can’t do anything to stop it,” Mullen said.

Depression affects people in different ways. There are varying degrees and different symptoms. But no matter what type of depression people have, these always apply: Depression isn’t weakness or a choice. It isn’t the same as “sadness.” And you don’t have to look depressed to be struggling. Learn more below.

Depression isn’t weakness.

In other words, it isn’t some inherent flaw or sign that someone is weak-minded, faint-hearted, too sensitive or a powerless wimp. Depression is an illness. Plus, people who have depression are actually quite resilient, said Mullen, PsyD, LMFT, the founder of the Coaching Through Chaos private practice and podcast in San Diego.

“Especially when people have recurrent depressive episodes — for them to continue to work towards improving their mood or understanding their depression is actually a sign of strength.”

Depression isn’t a choice.

“No one chooses to be clinically depressed,” said Hamilton, who’s maintained an independent psychology practice for over 20 years. But sometimes we make the mistake of thinking people do. We know that we have the power to change our perspective and outlook. We can challenge and restructure our thoughts. We can make meaningful changes. But individuals with depression can’t think away their depression any more than someone with diabetes can lower their blood sugar with their mind. Both are illnesses that require intervention.

With the help of a mental health professional, individuals can work through their depression and feel better. For some people medication is an important part of treatment (among other interventions). In short, depression is complex, and not something one can think away, will away or snap out of.

Depression isn’t sadness.

Depression and sadness are not the same thing. As Barbara Kingsolver wrote in her novel The Bean Trees, “Sadness is more or less like a head cold — with patience, it passes. Depression is like cancer.”

In her 1995 memoir, Undercurrents: A Life Beneath the Surface, Martha Manning also likened depression to cancer: “Depression is such a cruel punishment. There are no fevers, no rashes, no blood tests to send people scurrying in concern, just the slow erosion of the self, as insidious as cancer. And like cancer, it is essentially a solitary experience: a room in hell with only your name on the door.”

Depression is a constellation of symptoms, Hamilton said. People with depression may have difficulty concentrating and remembering things, she said. They might feel hopeless and disconnect from others, she said. They might have trouble sleeping and lose their appetite.

They might feel utterly exhausted, a kind of fatigue that knocks you off your feet. For some, getting out of bed feels overwhelming and impossible. Others go through the motions, appearing just fine but suffering in silence. Some report a dramatic deceleration, feeling as though they’re moving through mud.

Some people feel an all-over pain. Others experience headaches, stomachaches, back pain and joint pain. In fact, a high percentage of patients only report physical symptoms to their primary care physicians.

Depression doesn’t mean looking a certain way.

How often do we judge others by their appearance? When many of Mullen’s clients open up to friends about having depression, they hear: “You don’t look depressed!” But appearances don’t matter.

“Many people are very good at putting on a positive face in the morning and getting through their day, only to collapse into their depression in the evening when they are home,” she said. People hold down jobs while struggling with suicidal thoughts, she said. We don’t know what resides behind someone’s exterior, no matter how put together it might be. We can’t read minds or see into hearts.

If someone shares their struggles with you, avoid statements that sound like judgments of how depressed they may or may not be. Depression already comes with a lot of shame and revealing something so personal can make people feel extra vulnerable.

Whatever the symptoms or severity, clinical depression is a difficult illness. As a friend, partner, teacher, nurse or colleague, you can’t go wrong with appreciating its seriousness. You can’t go wrong with being compassionate, patient and understanding.

Tunnel photo available from Shutterstock