Gardaí have been undergoing weeks of training to qualify in public-order policing.
Officers highlighted increasing cases of violent, deranged persons (VDP), who may have mental health or drug problems and who take hostages in a home or lash out against themselves.
They said the problem is becoming more common with the availability of a number of prescription and illegal drugs, which are being consumed together, with dangerous outcomes.
Inspector John Egan said it is often family members who are forced to call in the Gardaí, and such call-outs are a traumatic experience for both officers and witnesses.
He said: “Unfortunately it is more common, a lot of the times it’s at home, it’s very unnerving for families.
“Parents who will call and say their daughter or son has taken something upstairs, they don’t know what the scenario is.
“My officers have to be trained, and be able to look after themselves, it might look aggressive at the outset, but if you have a knife or a samurai sword coming at you, you need the training and equipment to deal with that scenario, and for the safety and human rights of that person, they deserve full human rights, that’s not them on a normal day and we have to remember that.
A lot of it is down to drug-taking, a lot of different drugs are available at the minute and people are taking prescribed and non-prescribed drugs.
During the annual courses, Garda members are trained and tested in their competence in public order policing skills.
Asked on whether Brexit has led to concerns over public order, Gardaí said such training takes place every year and they have “no big announcement” on the issue.
Exercises involve resistance to Garda units from peaceful protesters, and controlled and staged violence, which includes withstanding missiles, petrol bombs, and physical attacks.
To qualify, officers must also complete intense fitness tests while wearing protective clothing and also complete training in human rights.