In a proceeding for permission to administer antipsychotic medication to William E., a mentally ill person, without his consent, the appeal is from a judgment of the Supreme Court, Kings County (Cutrona, J.), dated March 4, 1999, which, after a hearing, granted the petition.
Ordered that the judgment is affirmed, without costs or disbursements.
Contrary to the appellant’s contention, the petitioner established by clear and convincing evidence that the appellant lacked the capacity to make a reasoned decision with respect to the proposed drug treatment and that the proposed treatment was narrowly tailored to give substantive effect to his liberty interest (see, Rivers v Katz, 67 NY2d 485, 497).
*486The uncontroverted evidence established that the appellant, a 56-year-old man suffering from schizophrenia, was unable to understand the nature of his illness and thus lacked the capacity to make a rational decision with respect to his treatment (see, Matter of Adele S. v Kingsboro Psychiatric Ctr., 149 AD2d 424; Matter of McConnell, 147 AD2d 881).
In addition, both the appellant’s treating psychiatrist and the hospital’s psychiatrist agreed that his prognosis for improvement without changing his medication was poor and that he would remain institutionalized. The proposed drug treatment was expected to abate his delusions which otherwise made it impossible to reason with him. This in turn would allow him to take newer antipsychotic drugs which have no side effects and to participate in schooling and training programs which would allow reentry into the community (see, Matter of McConnell, supra). Joy, J. P., Krausman, H. Miller and Feuer-stein, JJ., concur.