As parents, you should learn the basic signs of mental health problems that may come up during adolescence.
You shouldn’t dismiss any abnormal behaviour and say the problem is “just adolesence”.
Behavioural changes may be caused by mental illnesses such as:
Autism spectrum disorder
Oppositional defiant disorder
Substance abuse disorder
And so on…
No. I’m not asking you to start googling these disorders and labeling your child who is going through the normal phase of adolesence. All I’m saying is that you should be vigilant enough to know when the flags are turning red.