According to the figures, the DHB's funding for mental health services increased from $52,636,000 in the 2013 to 2014 financial year to $53,457,000 in the 2015 to 2016 financial year.
Full time equivalent staff went from 303 to 314 over that time period.
Mr McKenzie said Northland DHB invested an extra $1m to $2m in mental health and addiction services every year.
"Hence, we now spend over $10 million more a year on mental health and addiction services than we did five years ago," said Mr McKenzie.
Recommendations from a recent mental health review provided longer term sustainable solutions to the ongoing challenges of trying to meet rapidly increasing demand with finite resources.
Mr McKenzie said they would be carefully prioritised against other service demands and health needs.
Figures showed alcohol abuse was the most common cause of referral for all age groups between 20 and 69 in Northland last year. Schizophrenia and major depressive disorders were also common.
Attention-deficit/hyperactivity was the most common cause for younger age groups. Dementia of the Alzheimer's type was the most common cause among older age groups.
Mental Health Foundation chief executive Shaun Robinson said the Ministry of Health had confirmed demand on youth and adult mental health services had grown by 70 per cent nationally in the last 10 years.
"We can only speculate as to what is causing the increase - some research in this area is needed."
Part of the increase could probably be attributed to the work that had been done in encouraging people to ask for help when they were experiencing mental health problems, he said.
"However, research has demonstrated that our young people are experiencing unprecedented levels of stress, and this is resulting in increased levels of depression, anxiety, behavioural problems, and lowered self-esteem and confidence.
"They are facing huge challenges that no generation in history has had to overcome. The economic and social environment they are growing up in is changing rapidly."
Mr Robinson said young people were also being constantly bombarded by a relentless stream of negative information from online and traditional media that created a feeling that the world was unsafe and uncertain.
"It's a stressful time for all of us, but especially young people who are simultaneously facing the age-old struggles of how to find their place in the world."
Additionally, too many young people were facing issues such as child poverty, sexual abuse, domestic violence and the pressures brought on by the housing crisis.
"Combined, these factors place young people at heightened risk for mental illness."
Mr Robinson said the foundation had always advocated for funding for mental health services to increase in line with population growth.
"We need to consider not just the amount of funding but how it is being used. It seems timely to ask whether we're doing enough to decrease the prevalence of mental health problems by improving the wellbeing of our young people and increasing their capacity to overcome difficult times."
Mr Robinson said the Mental Health Foundation promoted the Five Ways to Wellbeing - connect; keep learning; take notice; give; and be active.
"By practising the five ways, we're better equipped to cope with the ups and downs that are a natural part of life, but can - when we don't have the right skills and strategies to help us face them - lead to mental illness or distress," he said.
Where to get help:
• In an emergency: call 111
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youthline: 0800 376 633, or text 234 (available 24/7) or talk@youthline.co.nz or live chat (between 7pm and 11pm)
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155 (weekdays 11am to 5pm)
• NetSafe: 0508 NETSAFE (0508 638 723), www.theorb.org.nz