The puzzling symptom of paranoia

Paranoia can present as a symptom, a syndrome or as a personality trait. We present a series of cases, in adults, adolescents and children, where paranoia is the most prominent feature in the clinical presentation, with the objective of discussing difficulties encountered in diagnosis. A total of nine cases are presented where the initial diagnosis needed subsequent revision. The possible reasons for this are inadequacy of diagnostic classification systems leading to false positive diagnosis, unfamiliarity with certain diagnostic categories, absence of systemic evaluation and cultural factors.