What a month shows
Everything so far has been argument, and an argument can only take you so far against twenty years of evenings. The belief that the glass relaxes you and makes you good company has never been tested in your adult life, because the glass has always been there. A child riding with stabilisers can't find out whether she can balance while they're still bolted on. At some point they have to come off for an afternoon.
So the book's main suggestion is an experiment. Take a month without alcohol, and during it do every single thing you'd normally drink for.
The second half of that sentence matters more than the first. If you spend the month at home avoiding everyone, you'll have tested nothing, and you'll come out believing that life without drink is lonely. Go to the fortieth. Go to the pub on Friday. Cook at ten to seven with the radio on and something cold in a glass. The point is to find out what the setting can do with the glass taken out.
I'd choose a month, and not cutting down, for a particular reason. Cutting down leaves a glass in every situation, so the credit never gets tested. You'd be a bit less sedated at the same events, and you'd still walk in via the bar. Cutting down may well be where you end up. It's a poor way to run the test.
A week isn't long enough, because the first week is the worst evidence you'll collect. The ten to seven cue fires and gets no answer. Sleep may be unsettled. Whatever rebound you carry is still working through. You're watching yourself all the time. Judging life without alcohol on those seven days would be like judging a job by the first morning. A month holds several Fridays, probably a social event or two, and at least one properly bad day, and it gives sleep time to settle.
There's some research on what people find. In 2018 a team at University College London studied 94 moderate to heavy drinkers who took a month off, and 47 who carried on. They were drinking about 32 units a week on average, and nobody with dependence or liver disease was included. After the month the abstainers' insulin resistance had fallen by about a quarter, their blood pressure by about 6 per cent and their weight by about 1.5 per cent. The group who carried on showed no change. The participants chose which group to be in, so it wasn't a randomised trial.
In a survey of 4,232 people doing Dry January, de Visser and Nicholls found that wellbeing and people's sense of being able to manage their lives both rose over the month, and rose more in those who completed it. These were volunteers again, with no comparison group. A larger study followed about 10,000 adults in Hong Kong and checked its findings against 31,000 in the United States. Women who'd been moderate drinkers and stopped showed a better change in mental wellbeing than women who'd never drunk, and came close to their level within four years. That finding was in women, and the study was observational.
None of this proves you'll feel better. What it does is remove the fear that the evidence points the other way. When people stop for a while, the research doesn't show their lives getting worse.
Keep brief notes, because memory will flatter whichever conclusion you started with. In the first week and again in the fourth, write down how you slept and whether you woke at four. Note your mood at eleven in the morning and how wound up you were at ten to seven. After any social event, note how long the stiff part lasted and how the rest of the night went. Note the bad things too. Some evenings will be flat. The first party may feel stiff for forty minutes and not twenty. That's part of the result, and leaving it out would spoil the experiment.
One repeat of the caution from the start. If you get sweats, shaking, morning anxiety or nausea when you go without a drink, this experiment isn't for you yet. See your GP or an alcohol service first, because stopping suddenly can be dangerous when the body is dependent.