More people seek help for problem drinking in the three months following Dry July, the Salvation Army says.
Dry July is a campaign to encourage people to give up alcohol for a month in an effort to raise money to support cancer patients.
The fundraising programme began in Australia in 2008 and expanded to New Zealand in 2012.
Money raised goes to hospitals throughout the country, mainly to provide more comfortable spaces for patients and their families.
The Cancer Society has also received funds from Dry July for patient transport services.
For several years, Salvation Army Bridge, the organisation's drug and alcohol addiction programme, has seen an increase in people seeking help throughout August, September and October.
Addiction Services national director Lynne Hutson suspects those participating in Dry July are reviewing their drinking behaviour after a month of abstinence from alcohol.
Three to 10 per cent of the adult population, "depending on the method of diagnosis", are moderately or severely dependent on alcohol, Ms Huston says.
The Ministry of Health's 2014/15 national health survey shows 18 per cent of adults are "hazardous" drinkers, meaning that their drinking affects relationships or risks physical or mental health.
Dry July "gives participants the chance to pause and take stock of their drinking behaviours", Ms Hutson says.
The Salvation Army is encouraging people to contact their doctor or addiction treatment services if they are concerned about their alcohol consumption.
"Taking early action can avoid a great deal of heartbreak, illness and even catastrophe," Ms Hutson adds.
Dry July begins today. More information is available at www.dryjuly.co.nz.