Methamphetamine (MA),an extremely addictive synthetic stimulant,has quickly spread to become the most frequently used illicit drug in China.People with a history of chronic and heavy MA use have a high possibility of exhibiting schizophrenia-like psychotic symptoms,mainly delusions of reference,auditory hallucinations and cognitive deficits.These emerging findings suggest MA use increases aggression and violence and that there is a correlation between MA use and violence.However,it is unclear how to assess the capacity of criminal responsibility in “MA-induced” psychosis and how to set clear boundaries between schizophrenia and MA-induced psychosis when only limited and inconsistent evidence is available.Furthermore,a final persuasive differential diagnostic method based on improved understanding of schizophrenia and MA-induced psychotic disorders has yet to be developed.This paper will evaluate the epidemiology,social harm,and forensic psychiatric assessment of MA users,propose a future direction for the differential diagnosis between MA-induced psychotic disorders and schizophrenia,and put forward some practical solutions to assess the capacity of criminal responsibility of defendants with drug-induced psychotic disorder.