The effects included unwanted pregnancies, child neglect and depression. It also played a part in youth suicide and the vicious cycle of unemployment and poor mental health.
Dr Mills said the Far North had a higher concentration of liquor outlets than many other parts of the country, and greater deprivation, so measures that might not be needed in more privileged communities had to be considered.
Reducing liquor sale hours was "no magic bullet" but was one of the few tools local government had. Making alcohol less available in the mornings would have a positive effect on people addicted to alcohol and on all-night drinking parties.
However, lawyer Andrew Braggins, acting for the Progressive supermarket chain, said it didn't make sense that reducing the period in which alcohol was available would affect all-night parties. Nor was there any evidence that reducing the availability of alcohol in the morning would help alcoholics.
Earlier lawyer Padraig McNamara, acting for the council, quizzed Mr Reilly on police statistics showing a decrease in alcohol-related crime between 2012 and 2016. He suggested that was due in part to other council initiatives, such as education and risk-based licensing.
Police also gave evidence, Sergeant Mike Plant (Whangarei) saying alcohol was involved in 80-90 per cent of family violence incidents police dealt with.
Mr Reilly has no lawyer but is assisted by ex-council staffer Jane Johnston. While the appeal was in his name he said he was "the voice of a big community."
The council, supermarket companies and liquor outlets earlier struck a compromise over trading hours, but the matter still went to appeal because Mr Reilly wouldn't budge.
Whatever the outcome, all the Authority can do is send the provisional Local Alcohol Policy back to the council to be reconsidered.