05/08/2014 04:35 EDT | Updated 05/09/2014 11:59 EDT

What Is Depression? 17 Facts To Know

People may associate depression with things like having the "blues," being sad about the weather, and often, a "phase" they will just get over.

However, living and treating depression is usually far from what people see or hear, and instead centres around doctor appointments, coping with your mood, and for some, suicidal thoughts.

"Unfortunately, many people have been misled about the facts of depression from what they’ve seen on TV or in the movies, or have heard about from their friends and others," says Dr. Prakash Masand, a psychiatrist and president of Global Medical Education based in New York City.

In Canada, it is estimated that about eight per cent of adults will experience major depression at some time in their lives, according to the Canadian Mental Health Association, and almost one half (49 per cent) of those who have suffered from depression or anxiety never go to a doctor to get checked.

Masand adds this could be because people are often unsure of depression symptoms. The most common symptoms include feelings of guilt, sadness, worthlessness, changes in weight or appetite, and changes in sleeping patterns or insomnia. Other symptoms include a lack of interest in sex, frequent headaches or lack of motivation. However, this doesn't mean those of you who feel one or some of these symptoms are necessarily depressed. Self-diagnosing can be inaccurate, and Masand says always seek the help of a healthcare professional for further testing.

Depression has been linked to other disorders like bipolar disorder (manic-depressive illness), postpartum depression and psychosis, but clinical depression is the most common, according to the Public Health Agency of Canada.

Misleading information can result in stigma or assumptions about people living with and being treated for depression. To debunk the myths and give us the facts, here are 17 things you may not know about this mental health illness.

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It's Not Just About Being Sad

There’s more to depression than just feeling sad all the time, says Dr. Prakash Masand, a psychiatrist and president of Global Medical Education. Symptoms of depression can include psychomotor (cognitive functions and physical movement) activity changes, trouble sleeping, loss of interest in pleasurable activities, feelings of guilt or hopelessness, decreased energy, trouble concentrating, appetite changes, while others may also have suicidal thoughts or attempts.

Who Has It?

One in six people will develop major depression in their lifetime, Masand says. "Major depression affects 121 million people worldwide. Two out of three individuals with depression do not receive adequate treatment."

The Issue Of Suicide

Depressed individuals are five times more likely to commit suicide, Masand says. In Canada, a 2009 report from Statistics Canada found depression was the most common illness among those who committed suicide, with approximately 60 per cent suffering from this condition. That year, there were 3,890 suicides in Canada,

It Doesn't Mean You Can't Live Your Life

Being diagnosed with depression doesn't have to stop you from living your day-to-day life or seeking professional help. Most people would never guess celebrities like Brad Pitt, Oprah Winfrey, Billy Joel and J.K. Rowling all battled depression.

It Can Be Expensive

In Canada, one 2012 report found depressed workers who take a leave of absence or schedule in doctor or therapy appointments during work hours, can cost an employer up to $18,000.

New Moms Can Get Hit

Masand says one in 10 new mothers will develop postpartum depression. "This is by no means a character flaw or weakness. Symptoms of depression or the 'baby blues' can occur in many women." Mothers who feel like they do have symptoms should seek treatment and not put it off.

Women Are More Likely To Be Depressed

Masand says women are twice as likely to develop depression as men, and although depression can strike at any age, the average age of onset is 32.

You're More Likely To Have A Heart Attack

Patients with depression are also more likely to have heart attacks and strokes compared to non-depressed individuals, Masand adds. Researchers note some symptoms of depression can reduce your overall physical and mental health, which increases your risk of heart disease or make symptoms of heart disease worse.

It's Not Just Adults

One out of 10 adolescents will have depressive disorder by the time they're 18, Masand says. "Compared to adults, children with depression may be more likely to present temper tantrums, somatic complaints, social withdrawal and mood liability."

It Doesn't Always "Go Away"

If you are seeking treatment or taking antidepressants, Masand adds it's not as simple as being symptom-free in a few weeks. "Medications take time to work, and a 10 to 12 week trial is necessary to achieve remission," he says. He also adds cognitive behavioral therapy and interpersonal psychotherapy are good options to moderate depression.

Depression And Bipolar Disorder Are Not The Same

Sometimes, people are misdiagnosed or use the two conditions interchangeably. Masand says healthcare professionals should also ask about the history of a patient's experience with hypomania and mania — both of which are linked to being bipolar.

Sometimes Being SAD Is More Than Just SAD

Many patients with seasonal affective disorder (SAD), which is winter depression, have undiagnosed bipolar disorder, Masand says. Again, this can be tracked by looking at the patient's medical history, and experience with hypomania and mood levels. Often, professionals (and patients) wait around for the weather to get better to feel better.

Exercise And Yoga Can Help

Masand says studies have shown exercise and yoga can be very helpful with patients with depression. "When you exercise, you release endorphins, a chemical in the brain that brings about a positive feeling over the body." The benefits of exercising in general include longer and deeper sleep, improved self-esteem and confidence, reduced stress and alleviated depression and anxiety.

How Is It Diagnosed?

There are no laboratory tests or brain scans that can diagnose depression, Masand says. Instead, doctors talk to patients about family history, look for depression symptoms and at the same time, rule out other conditions to narrow down depression.

Hidden Causes

Masand says many medications like steroids or isotretinoin have been linked to causing depression. If you recently started taking a new medication and are feeling the symptoms of depression, talk to your doctor or pharmacist about potential side effects.

The Link Between Antidepressants And Suicidal Thoughts

Antidepressants don’t usually increase suicidal thoughts and suicidal tendencies, Masand says, but some studies have shown a correlation with an increased risk in some patients. In particular, children, teens and those under 24 tend to have a higher risk of having suicidal thoughts. In this case, anyone under 24 should be monitored extra carefully for any suicidal behaviour.

Resiliency Can Be A Good Thing

People with the resiliency trait are less likely to develop depression. "The reason for this isn’t totally understood, but resilient people typically have a stronger belief in themselves, don’t let adversity bring them down and are more confident," Masand says. He adds these types of behaviours are also taught in therapy.