Depression affects people in different ways, many of which aren't talked about, or even known about. In fact, I was diagnosed with depression nearly seven years ago, yet I only learned some of the symptoms in the past couple years (several of which I had definitely experienced).

The feeling of not knowing why you're acting a certain way is extremely frustrating and only leads to worsening the symptoms you're already experiencing. The two most common symptoms people talk about are sadness and low energy, and while those are certainly prevalent among those facing depression, there are still so many more people don't talk about enough.

1. Irritation & Anger

People with depression may experience feelings of agitation, sometimes for no reason at all. I remember constantly being mad, and sometimes taking it out on the people around me. I would always feel badly afterwards, but I couldn't control my feelings at the time. It's not nearly as known, but this is extremely common.

2. Fatigue

Not only do people with depression have low energy, they also feel overwhelming tiredness. I remember sitting in class and not physically being able to keep my eyes open, despite having slept a full night. I was constantly yawning and it was almost impossible to wake me up in the morning. Fatigue can really inhibit the ability to function in daily life.

3. Feeling Worthless and/or Guilty

These feelings are enough to sadden people who don't have a mental illness, but many who have depression are unable to get away from these destructive thoughts. It's a cycle of feeling worthless, then guilty because of how your illness is affecting those you love, then trying to 'buck up' and get better, then feeling worthless again, and so on.

4. Apathy

Feeling numb or 'empty' is another common symptom of depression. This is especially evident when people don't find joy in the activities they used to love. It can also affect your relationships because people think you don't care. In reality, there are a storm of emotions somewhere in your head, but people with depression either can't access them or can't express them. It's like a fog is completely surrounding you.

5. Physical Pains

This was one symptom I had no idea about, but is actually common (especially for children). Many people with depression report various aches and pains, especially headaches.

6. Insomnia or Hypersomnia

Issues with sleep are also very prevalent among people with depression. This could mean not being able to fall asleep, tossing and turning all night long, or sleeping way too much. For me personally, I had problems with both. It would take me two or three hours to fall asleep, but once I did, I was out for up to twelve hours. One particularly bad weekend, I slept for over thirty-six hours straight.

7. Doing Everything Slowly

For me, this was a hard thing to catch, but once I noticed it I realized how often this affected me, as it does many other people. It seems like you couldn't move any faster even if you wanted to. Coinciding with the symptoms of physical pain, I felt aches all over my body, and knew that moving faster would give me more of a headache than I already had.

8. Low Self-Esteem & Self-Loathing

For me, this was (is) one of the hardest symptoms to deal with. As much as you're told differently, as often as you try to logically talk your way out of thinking awful things about yourself, it's impossible to escape these thoughts. People with depression can't control their brains, and because of that they can feel horrible just for existing.