hello, I am new to this forum. I have been reading for a few days and I noticed quite a few families have more than one child with-some sort of diagnosis; my question is how to distinguish between a second child actually have a mental health issue causing disruptive behavior and when the child is just mimicking what they have watched thier sibling do for years,(IE: learned behavior with a touch of PTSD). Honestely, I have found the 'professionals'' to be as confused as me on this issue. My 13 difficult child is bi-polar and global Learning Disability (LD) , we have known something was not quite right for many years (like 11 yrs), known she was Learning Disability (LD) for about 3 but in the past 2 years the behavioral isuues became more severe, (divorce and puberty about same time, triggers?). Anyway, after being told by many and assumed by many more that this was a parenting problem , finally she was diagnosis'd with mood disorder (leaning toward BiPolar (BP)), which is what I had already figured out. Thank GOD, the very firstmeds they put her on post diagnosis (before diagnosis tried very wrong medications -scary reaction) have worked very well with little side-effects , now she is just a typically cranky, lazy, rebellious 13 year old, a dream compared to what we had before. anyway, I live and am involved in a very small community and as I said many assumed and still do that this was a case of bad parenting, well to make matters worse now my 9 year son has decided that he wants to join the disfunctional behavior bandwagon. Eldest started medications in early winterof '07' and was a changed person within weeks (do not get me wrong still cantakerous), and a few months later her 9 year brother was kicked out of school due to his behavior (private school). He has no learning or attentional difficulties, it is purely behavioral. He has always had a temper but seems to have escalated over past year. he does well in structure, but give hom a free moment and then let someone (child or adult) say or do something he does not like and he can fly off handle. He has beaten schoolmates and cussed at the principal, and of course me. He would start punching and kicking anything in sight iof he did not get his way with me, and I am not a permissive parent . alot of cussing..still. psychiatric said maybe combo of bio, and ptsd, and enviromental, also said he is past ODD. We put him on medications temprarely to try and calm him while trying to get him to cooperate in therapy, medications make quite a difference he tries to control himself now and catches himself when he begins to fly off the handle, stop medications a few days and we are back to old behavior. soo.... how do I know? learned behavior or own chem imbalances or a bit of both? The fact that the medications make a difference mean anything regarding his chemical balance? Dr.s seemed stumped so I am turning to the real experts the experienced/veteran parents. sorry, I have a habit of writing very long passages hope someone can make it to the end of this and add thier thoughts, advice.