You have already seen that in affirmative sentences with depuis (= I have done this since/for + [date/duration]), you must use Présent indicatif in French, unlike the English Present Perfect.
See lesson Using 'depuis' (since / for) with Le Présent and NOT Le Passé Composé (prepositions of time)
But things change when it comes to negative statements (ne...pas) with depuis.
Indeed, in such cases, you will actually use Passé composé in French, as such:
Here we use Passé composé because the use of the negation ne ... pas insists on the fact that the action wasn't done during the entirety of that past period, hence Le Passé Composé.
Using Présent indicatif here sounds like you're talking about a current action with a past date, which is non-sensical
-> You don't drink alcohol for 5 years.
To emphasise that a (recurring) action in the past has now stopped happening with depuis, you can also use Présent indicatif with ne ... plus (not any more) instead of ne ... pas. Here ne...plus focuses on the change between the past situation and the new current one, which it highlights, hence Le Présent.
Special case of depuis longtemps = not long vs not in a long time
Ne ... pas + Passé composé + depuis longtemps
OR
Ne ... plus + Présent indicatif + depuis longtemps
= not for a long time / not in ages
-> It's over and done in the past
OR
Ne ... plus + Présent indicatif + depuis longtemps
= not for a long time / not in ages
-> It's over and done in the past
ATTENTION:
Ne ... pas + Présent indicatif + depuis longtemps = not long / not for long
-> It started a short while ago, and is still ongoing
See also Expressing for + [duration] with either pendant, durant, depuis or pour (prepositions of time)-> It started a short while ago, and is still ongoing
Want to make sure your French sounds confident? We’ll map your knowledge and give you free lessons to focus on your gaps and mistakes. Start your Braimap today »