Here's the very broad criteria from the ICD10 code book used in billing DP.
A disorder characterized by the presence of one or more nonbizarre delusions that persist for at least 1 month; the delusion(s) are not due to schizophrenia or a mood disorder, and do not impair psychosocial functioning apart from the ramifications of the delusion(s).
A kind of psychotic disorder
A mental disorder in which a person has an extreme fear and distrust of others. A paranoid person may have delusions that people are trying to harm him or her.
Chronic mental disorders in which there has been an insidious development of a permanent and unshakeable delusional system (persecutory delusions or delusions of jealousy), accompanied by preservation of clear and orderly thinking. Emotional responses and behavior are consistent with the delusional state.
Disorder with presentation of a facade of coldness with characteristic pervasive mistrust and suspiciousness of others.
Gradual development of an elaborate and complex delusional system, usually involving persecutory or grandiose delusions with few other signs of personality or thought disturbance.
Mild paranoia in nonpsychotic persons.
Psychotic behavior accompanied by persecutory or grandiose delusions with few other signs of personality or thought disturbance.