Students with emotional impairment or emotional behavior disorders often act out in class. Most of helping these students as an educator is dealing with disruptive behaviors. Usually these students will have other experts like a therapist or social worker to deal with the base issues. Your job in class is to support those other professionals as well as curb undesired behavior.
Acting out cycle
Calm phase
The ultimate goal is to keep students in the calm phase where they are cooperative and engaged.
Giving a student enough attention of the right kind is helpful to staying in calm phase.
Trigger
This is the inciting event to problem behavior.
It can be an interpersonal conflict, not understanding something, or even being hungry or tired. (Yes, your student can arrive at school not in the calm phase.)
You can use "precorrection" to manage triggers. Clarify expectations to help them meet expectations.
Agitation
This phase can go on for a while.
Is often characterized by fidgeting, moving around, stopping and starting tasks.
Intervention needs to happen as soon as agitation becomes evident otherwise it might be too late and acceleration is inevitable.
Acceleration
The student becomes more focused on getting teacher attention: questioning, arguing, breaking a pencil...
This is often when teachers first notice something is wrong, despite the previous clues.
Do not engage them. Acknowledge their feelings. Offer a prompt and walk away. Positive enforcement for accomplishing anything.
Peak
Behavior is out of control and not stoppable at this point. This is the largest action in the cycle (violence, yelling, destruction).
Keep everyone safe - follow your school's plan for this. Every school has a plan, often a removal policy. Removal has a downside of teaching the student that acting like this gets them out of class.
De-escalation
This is the time after the peak where the student may withdraw or deny responsibility. They usually don't want to discuss what happened.
Help them get out of this with dignity. Give them an independent activity in a quiet space to withdraw with your permission.
Recovery
Students are subdued.
This is the time to debrief on the incident. Acknowledge uncomfortable feelings. Ask to figure out the trigger.
Also debrief the class. Reinforce expectations and tell the class to be kind to the student who acted out.
Own up to mistakes, particularly not recognizing something was wrong earlier.
The key is to intervene early in the acting out cycle. It is common to hear teachers say things like, "The student did this out of nowhere" but it was usually not out of nowhere. There were earlier signs in the acting out cycle.
This works with any student who might act out, but you see this behavior more often in students with emotional behavior disorders.
References
The IRIS Center. (2005). Addressing disruptive and noncompliant behaviors (part 1): Understanding the acting-out cycle. Retrieved from https://iris.peabody.vanderbilt.edu/module/bi1/