The Lost Weekend (1945)

Billy Wilder's seriocomic Noir about a blocked alcoholic writer who purposely misses the weekend country getaway his brother planned for both of them in order to spend it in town, drinking.

I've heard the source novel offered his homosexuality (which is not addressed here) as an explanation for his addiction; but in this adaptation, it's merely caused by his inability to live up to his own boy genius expectations.

Either way, the explanation is unsatisfactory by contemporary views of addiction, I would imagine.

Yes, the man goes back to suicidal thoughts he's had in the past, and he even acts on them, but the Just Say No answer is merely unrealistic movie shorthand.

Even with a flashback narration from three years before (he has been supported by his tight-on-the-purse-strings brother for the last five years, and for all we know he's never held a job,) the events of the titular lost weekend seem mild compared to subsequent films dealing with addiction in even more extreme or outrageous terms, (do you think dropping a cigarette into a glass makes the booze undrinkable? Ha! You haven't yet seen Sideways (2004)!):

He steals ten dollars from a cleaning lady, spends the afternoon at a bar; disappoints his brother and girlfriend; drinks one bottle; disappoints a hooker (Movie Rule # 385: Drunks must always end up with a cute, nice, hooker with a heart of gold: Arthur (1981), Leaving Las Vegas (1995), etc.); gets kicked out of a club for stealing a purse; begs for a drink; finds a lost bottle and drinks it; begs the hooker for ten or five dollars; falls down the stairs, drunk; escapes from the alky ward in his pajamas; (in the second of two fantasy sequences) hallucinates a simultaneously disturbing and hilarious mouse and vampire bat attack, (the man suffering DTs by imagining bugs on himself at the ward is much more seriously disturbing); then gets a gun at a pawnshop to commit suicide.

Suicide is extreme, certainly, but the events leading up to this hardly seem like rock bottom to me.

While the subject might be as grim as can be, the mood is lightened by some of the hysterical extremes we see:

A scene at the opera house where he can't concentrate on La Traviata because he's distracted by all the bottles and drinking on stage concludes with him imagining all the players have turned into the coat he checked in which he had left a bottle of booze.

It's funny enough to see him licking his lips at the stage liquor, but the Bugs Bunny-like hallucination goes over the top.

There are many times he is able to get the drinks he wants, but the times he is frustrated become humorous in comparison, particularly him finding all the pawnshops (even the Irish ones) are closed despite it being a Saturday because it's a Jewish holiday and all the owners in town have an agreement.

Ray Milland does a believable job as an alcoholic, though his slurred speech and mannerisms might come and go, but I can't imagine those other elements weren't meant to be humorous.

Despite the limitations of the time, it calls alcoholism a disease (I have no idea what the proper, contemporary P.C. way of addressing addiction is,) but the film seems somewhat prescient for this.

With Jane Wyman, Phillip Terry, Howard Da Silva, and Doris Dowling

It virtually won all the awards that year and has lost little of its power since.