There is obviously a two level problem here. In the first instance the child. By simply posting on a Forum is certainly not going to remedy the situation.This is a young child we are discussing. Whether he has a behavioural problem doesn't matter. This is abuse -- five nights a week roaring and shouting. God only knows what lies behind the doors. To clear your concience, surely you should report to the Gardai and Social Services.
On the second level, who knows what type of problems the mother has. She may have a personality disorder herself. Or even some kind of an addiction problem. One thing certain, this entire matter requires to be dealt with by the professionals and ASAP, before you are back on this forum again detailing a disaster.How many times have we watched Sky news with unbelievable reports of pathetic child abuse.
Finally, if you are renting your apartment, why should you have to put up with this nightly disturbance. Have you lodged a complaint to the MC who could have these people evicted. This solves your problem of peace and quiet but just lets the main problem continue.
Please report this matter before the child especially becomes another horrible Statistic.