As too many people know only too well, mental health is a world of unmet needs and untold suffering. Society’s ability to identify and treat emotional ailments and addiction is painfully inadequate. Families, left to themselves, struggle and fail. They often lack the resources to confront problems or don’t try: two things in plentiful supply are ignorance and denial.

Into this void, bearing a multiagency “road map” with a kitchen-sink approach, has stepped Mayor Bill de Blasio. In an emotional news conference on Monday, he unveiled a citywide initiative, called “ThriveNYC,” to tackle mental illness and addiction.

The plan’s six “guiding principles” and 54 programs encompass widely varying things like training for 250,000 New Yorkers in mental health “first aid,” a public-service ad campaign, early-childhood programs teaching social and emotional skills, more screening and treatment for maternal depression, and new initiatives in online education and data collection.

The human element includes 100 consultants in the schools to connect students with care, as well as a “Mental Health Corps” of 400 doctors and clinicians to work in high-need neighborhoods. Together with other programs, like the mayor’s recently announced plan to build 15,000 units of supportive housing for those who need social services as well as housing, ThriveNYC is meant to strengthen the web of protection for the city’s most vulnerable residents, on par with Mayor Michael Bloomberg’s groundbreaking advances in fighting smoking, obesity and other threats.