We use the process verb become to describe a change of state.  Other process verbs include:
come        fall        get        grow        run        turn(into)        wear
The nights are becoming longer and the days shorter.
It’s growing dark.
My boots are wearing thin.
He’s turning into a polite and charming young man.

Tense
Note that when describing change, the present simple tense should not be used. We should use the present continuous tense for things that are changing and the present perfect tense for things that have already changed.

e.g.
Charlie’s grades are below average this semester so he becomes depressed.
Charlie’s grades are below average this semester so he’s becoming/he has become depressed.

Get/become
We use get rather than become in colloquial English, in imperatives and in phrases like:
get broken, get dressed, get divorced, get killed, get lost, get married, get washed
We often use get in combination with certain adjectives e.g.
get angry, get ill, get bored, get depressed, get wet, get drunk

Examples:
When he lost his job, he got divorced soon after.
Get out of bed and get washed at once!
You’ll get killed if you jay walk like that!
I got drunk at my best friend’s stag night.
We use become when we refer to a more abstract process of change.
e.g. He became recognised as a pioneer in the field of nanotechnology.
I’ve recently become aware of a distinct coldness in his manner.