Alcohol acts a lot like benzodiazepines in the brain, and it inhibits the serotonin transporter like SSRIs do, and it has NDRI-like action, as well. Personally, I think a lot of alcohol consumption is self-medicating to treat symptoms that could be treated with drugs with better safety profiles. Of course, self-medication with addictive substances leads to physical dependence, making it harder to substitute other drugs for alcohol after awhile.
I'm friends with someone who went from multiple organ failure in the hospital from chronic alcoholism, to recovery with psychiatric treatment, and it seems like GABAergics like gabapentin and an SSRI help them feel okay without alcohol. At least in the US, this can be prohibitively expensive, and they're stuck with tens of thousands of dollars of medical debt, but that beats being dead.
I think there's little doubt that those who consume excessive alcohol regularly over long periods are self medicating. I'm almost certain this was so with my aforementioned friend and colleague who died from the effects of alcohol.
Decades earlier he'd been hooked on benzodiazepines and could never seem to get enough of them. He was always concerned about being caught short without them and that his supply might run out before he could get a renewal of his prescription (supply became a problem in the '70s/'80's when doctors became aware that they were addictive and that too many people were abusing them). As he was an organic chemist by training, I used to joke with him that he should concoct up a supply in his kitchen.
For him, benzodiazepines where highly effective (at least so over the short term). I've seen him in a jittering state of nervous anxiety and being totally unable to function yet an hour or so after swallowing a couple of 5mg Valium tablets he'd be as normal and calm as everyone else around him. Of course, by then, it was impossible for me to determine how much of his anxiety etc. was part of his condition and how much was attributable to benzodiazepine withdrawal.
You are lucky that your friend was saved from multiple organ failure just in time with proper care, but that wasn't to be with him. Two or three years ago it would have still been so technically, but in the end his medicos, psychiatrist and his friends were unable to help—as essentially he refused to help himself.
Obviously, good medical care often helps but it seems to me we've still a long way to go before we've alcoholism licked for good.
I'm friends with someone who went from multiple organ failure in the hospital from chronic alcoholism, to recovery with psychiatric treatment, and it seems like GABAergics like gabapentin and an SSRI help them feel okay without alcohol. At least in the US, this can be prohibitively expensive, and they're stuck with tens of thousands of dollars of medical debt, but that beats being dead.