In general a person normally is quite capable of lying, hiding and so forth about anything including mental and physical health disorders, conditions, symptoms and what have you. human beings having this ability to think logically, strategize and lie, hide and so forth about all kinds of things including health issues is documented all the way back to cave men days.

whether you decide to hide your disorders and what comes with them is up to you.

my own opinion is

dont worry about whether you can or cant suppress / hide any mental disorders, symptoms and such.

If I remember right the last few assessments, you went through you purposely hid things and that resulted in you not getting diagnosed for the disorders you wanted to be assessed for.

if you dont want to get diagnosed just tell your treatment providers you do not want to go through the assessments right now. just deal with what you are willing to deal with in therapy at this time.

sometimes self sabotaging can happen on purpose and accidentally when someone knows too much about the mental disorders and whether or not that disorder is one you can or cant hide.

my suggestion is stop worrying about hiding your symptoms, problems, behaviors from your treatment providers.

if you want to be diagnosed, just go through the assessment with the attitude that this is a good thing. by getting a diagnosis you will be able to get more services and treatment options that actually fit your situation.

Also assessments for many mental disorders do take into consideration the ability to lie and hide a disorder. thats why many who try to hide things end up getting diagnosed with fictitious disorders imposed on self.

you really dont want on your record that you repeatedly go through various assessments and then hide your disorder or symptoms, problems and such.

if you are considering hiding your diagnosis, symptoms, problems and behaviors during the assessment then now is not the time to do the assessments.

that said as for hiding things as a teenager. thats normal and being a teenager. teens do naturally learn to suppress their feelings and such, what their peers dont agree with or bully others for. just normal life of teens. I have teens who are constantly trying to hide their feelings as each one entered that stage of puberty of wanting to fit in, dont let others in, dont let others see their emotions, protect their self from bullying and so on. normal teen age stuff.

not expressing feelings, emotions is considered a mental disorder when its not a learned or self taught thing.

example my special needs daughter was never one to express her emotions, not even when she was a toddler. that girl would be told no don't do something and she would look at me with a who cares doing it anyway look. when she was worried about a medical procedure unless you knew her you would think all was well, not a care in the world for it just was not in her to show her emotions. she rarely cried, even as a baby and toddler. trying to get a smile out of her some days is like literally talking to a wall.

Its not that she doesn't have emotions, she just doesnt have the ability to express them correctly. She isnt purposely like her siblings trying to hide her feelings from family friends and others.

her diagnosis is childhood schizophrenia and autism. as part of her autism/ schizophrenia her way is to naturally bottle things up. then explode in tantrums. medication is helping her. as is therapy work to learn how to identify her feelings and let them out in appropriate ways.

my suggestion is not worry so much about hiding things and either do the assessments or not whichever you want to do.