title: Clonidine normalizes sensorimotor gating deficits in patients with schizophrenia on stable medication.
abstract: BACKGROUND
  Cognitive deficits form core features in schizophrenia. Several studies have shown improvements in prefrontal cognitive function by α 2 -agonists in schizophrenia. In the present study, it was investigated whether clonidine (an α 2 -adrenoceptor agonist) could normalize sensorimotor gating deficits in schizophrenia.
  
  
  METHODS
  In a double blind, placebo controlled, randomized, yet balanced, cross-over experiment, 20 male schizophrenia patients on stable medication were assessed in an auditory prepulse inhibition (PPI), sensitization, and habituation of the startle reflex paradigm on 5 occasions: once after oral administration of placebo and after a single dose of 25, 50, 75, and 150 µg of clonidine. Their results were compared with 20 age- and gender-matched healthy volunteers, who received no treatment.
  
  
  RESULTS
  In the placebo treatment, patients showed deficient PPI and sensitization, yet normal habituation compared with the controls. Except the highest dose, all dosages of clonidine significantly increased percentage PPI in the patients compared with placebo, to such levels that it no longer differed significantly from the healthy controls. However, none of the dosages increased sensitization or influenced habituation.
  
  
  CONCLUSIONS
  This is the first study to show that even a single low dose of clonidine added to the medical treatment of patients with schizophrenia who are clinically stable on their antipsychotic medication not only significantly ameliorates their PPI deficits, but also normalizes them. The results have a potentially high clinical relevance for the medical treatment of schizophrenia.
authors: Center for Neuropsychiatric Schizophrenia Research (CNSR), Copenhagen University Hospital, Psychiatric Center Glostrup, Glostrup, Denmark. B.Oranje@cnsr.dk
authors: Bob
authors: B
authors: Oranje
authors: Birte Y
authors: BY
authors: Glenthøj
mesh_terms: D000161:Acoustic Stimulation; D058647:Adrenergic alpha-2 Receptor Agonists / Q000494:pharmacology* / Q000627:therapeutic use; D000328:Adult; D001767:Blinking / Q000187:drug effects; D003000:Clonidine / Q000494:pharmacology* / Q000627:therapeutic use; D003072:Cognition Disorders / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004576:Electromyography; D006185:Habituation, Psychophysiologic / Q000187:drug effects; D006801:Humans; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects; D013216:Reflex, Startle / Q000187:drug effects; D012559:Schizophrenia / Q000188:drug therapy / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D055139:Sensory Gating / Q000187:drug effects*
chemical_list: D058647:Adrenergic alpha-2 Receptor Agonists; D003000:Clonidine