From the Public Health Scotland report itself, page 78 (if the SNP can cherry-pick their favourite bits, so can I)
Look at Table 3 from the same report (pages 79-81).
It lists the scientific evidence and what was found:
One paper (and only one) showed the 13% drop that has been used to show this is a "success".
Four papers showed no impact of MUP
Two papers point out reduced spending on food in alcoholics
Others talk about crime, cross-border buying etc. But read the report - better yet, read the scientific papers themselves!
https://publichealthscotland.scot/media/20366/evaluating-the-impact-of-minimum-unit-pricing-for-alcohol-in-scotland-final-report.pdf