We should all be more aware and in control of our stress levels every day. While a little stress may be good for you, a lot can harm your physical and mental health, and is often a contributor to depression. In fact, your chronic stress may be depression, according to experts.

Learn how to tell stress and depression apart -- and when to see a doctor.

How Are Stress and Depression Related?

Stress can lead to depression, and depression can lead to stress. Early animal studies found that if you stress out an animal by shocking it, and there is no way for the animal to change its circumstances, it becomes depressed. Similarly, if you feel helpless to change your own stressful situation - such as financial issues or marital problems - you can develop depression.

With depression, it is common to feel hopeless about the future and lose interest in things normally found to be pleasurable. Key physical symptoms tend to be either insomnia or sleeping too much, either no appetite or too much appetite. Stress causes a lot of different symptoms, both psychological and behavioral, depending on the person. Some of the physical symptoms that may differ from depression include shortness of breath, palpitations and gastrointestinal problems. The gut is extremely sensitive to stress.

When Should I See a Doctor About My Mood?

If you have physical symptoms, see a physician to rule out anything organic (meaning an underlying physical problem). Once an organic factor is ruled out, go to a mental health professional who does cognitive behavioral therapy (CBT), which teaches you strategies to respond differently to stressful situations. It works fast and is normally covered by insurance.

Should I Take Medication for My Stress?

It isn't great for young, healthy people to go on medication when they don't really need to. A lot of people go to a primary care physician complaining of stress, and walk out with a prescription for an antidepressant. But SSRIs (a commonly prescribed class of antidepressants) are really only effective in people who are severely depressed. For mild to moderate depression, research shows that exercise, CBT and even acupuncture are more effective than SSRIs.

When you're stressed, you're revved up and feel like you have no time to exercise. When you're depressed, you often don't have the will to exercise. In both cases, it's really hard to get yourself out the door. But even taking a short walk will make you feel better. That being said, if you suspect you are depressed, especially if you have thoughts of harming yourself, it's important to get evaluated by a mental health professional immediately.

Take a Health Quiz