Hi. my son is 18 yrs old and suffering from schizophrenia.He has been taking Invega tabs for almost 4 yrs now, he started with 3 Mg then increased to 6, then 9 and now 12 Mg. he complains of getting severe headaches, I wonder whether is it because of the medication that he takes or? Further, invega tabs are very expensive and cannot afford his psychiatrist has advised to take Palido OD-12mg since they all do the same job. However the result is very low. Dr. please advise... and please advise whether he can get a cure of his disease. Thanks,