verb
depress
dih-PRESS/dɪˈpres/
To press or bring something to a lower level.
The finger depresses the button below the level of its raised neighbor.

Etymology
The literal image is pressing something downward, as with a button. Applied to feelings, the same downward movement became lowering people's spirits or making them gloomy.
In context
I don't like novels that end happily they depress me so much
More examples
- Depress the button to release the handle.
- This medication can depress breathing.
- High borrowing costs depress consumer spending.
Forms
depress · depresses · depressed · depressing
depressant noun — A substance that reduces nervous system activity.