title: Tourette syndrome and other tic disorders in a total population of children: clinical assessment and background.
abstract: OBJECTIVE
  To describe the symptoms, onset, heredity, pre-/perinatal events and socio-economic status in Tourette syndrome (TS) and other tic disorders.
  
  
  METHODS
  From a total population of 4479 children, 25 (0.6%) with TS, 58 (1.3%) with chronic motor/vocal tics (CMVT) and 214 (4.8%) with transient tics (TT) in the last year were found. A three-stage procedure was used: tic screening, telephone interview and clinical assessment. The TS group was compared with 25 children with TT and 25 controls without tics.
  
  
  RESULTS
  The mean age of the first symptoms of TS was significantly lower than the onset of CMVT. All except one with TS had contact with medical services. The tics of children with TS were significantly more severe than the tics of others. Younger age of onset of TS indicated more severe tics. Parents and siblings of children with TS had an increased prevalence of tic disorders, obsessive-compulsive behaviour (OCD), attention-deficit/hyperactivity disorder (ADHD) and depression. Eighty per cent had a first-degree relative with a psychiatric disorder. A non-significant increase with regards to reduced optimality score in the pre-, peri- or neonatal periods was found in children with TS compared to controls. No differences were found concerning socio-economic status.
  
  
  CONCLUSIONS
  Almost all children from a total population with TS have sought help from medical services. An increased prevalence of tics, OCD, depression or ADHD was found in the parents/siblings of children with TS, which draws attention to the importance of thorough investigation of family members.
authors.affiliation: Department of Neuroscience, Child and Adolescent Psychiatry, University Hospital, Uppsala, Sweden.
authors.forename: Najah
authors.initials: N
authors.lastname: Khalifa
authors.forename: Anne-Liis
authors.initials: AL
authors.lastname: von Knorring
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D000704:Analysis of Variance; D016022:Case-Control Studies; D002648:Child; D005192:Family Health; D005260:Female; D006801:Humans; D008297:Male; D008487:Medical History Taking; D012017:Referral and Consultation; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D013981:Tic Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics / Q000503:physiopathology; D005879:Tourette Syndrome / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics / Q000503:physiopathology