The Dutch healthcare system is referred to as a ‘gatekeeper system’ because the General Practitioner (GP) or family doctor (huisarts) is the first point of contact for healthcare. They are the ones who provide referrals to any specialist or hospital for mental and/or specific physical healthcare.
Health insurance is compulsory for every person who lives or works in the Netherlands, although there are a few exceptions (e.g. PhD students). You can check if you need health insurance at Zorgverzekeringslijn.nl.