You probably know someone who is depressed. You may be wondering about yourself. The way you feel right now–does it fit the definition of depression? Clinical depression is a serious illness that affects millions, so you are right to be concerned. Understanding depression is a good first step toward treatment. Let’s see if we can figure this out together.

First of all, having days when you feel down, or sad, is normal. We all have days when we feel blue, or down. It is just part of life. If those sad, blue feelings become your most predominant feelings however, like a dark persistent cloud, your emotions may not be just a “mood” but depression.

Depression is not a mood that can be alleviated by will power. Depression is a mental disorder that can change how you think. It changes your outlook on life and the future. It affects your beliefs and how, and if, you want to interact with others.

Since normal feelings of sadness, and the feelings of depression are very similar, differentiating between the two is usually by time and intensity. The feelings from depression are much more intense than a normal reaction to a negative event.

Two weeks is typically the threshold for diagnosing depression. If after a negative life experience you are still withdrawn and sad after more than two weeks it is possible you have entered into a depressive episode. Without treatment a depressive episode can last for months, sometimes years.

The good news is depression is treatable. Through a combination of therapy and medication, up to 80 percent of people with depression get better. But treatment takes time and involves some trial and error, so patience is a must.

No one is immune to the effects of depression. It is not an indication of weakness or failure. If you suspect that you or someone you know may be suffering from depression, it’s important to get professional advice as soon as possible.