title: Secondary nonmotor negative symptoms in healthy volunteers after single doses of haloperidol and risperidone: a double-blind, crossover, placebo-controlled trial.
abstract: OBJECTIVE
  The effect of antipsychotics (APs) on negative symptoms is controversial. The present study assessed negative symptoms in healthy volunteers without any source of primary negative symptoms after single doses of haloperidol and risperidone.
  
  
  METHODS
  Twenty-five healthy subjects were included in this randomized, placebo-controlled, single-dose (haloperidol 5 mg and risperidone 2.5 mg) crossover and double-blind clinical trial. Negative symptoms were assessed by observer-rated scales and with a self-report scale. Possible confounding effects considered were extrapyramidal symptoms (EPS) and sedative effects. The occupation of striatal dopamine D2 receptors was also determined.
  
  
  RESULTS
  Risperidone induced a wide range of negative symptoms such as alogia, blunted affect, avolition/apathy, and attention impairment, whereas haloperidol only induced the avolition/apathy subdomain. Most of the effects of risperidone in healthy volunteers, with the exception of its effects on avolition/apathy, were attributable to AP-induced EPS. Haloperidol did not cause significant EPS after administration. No effect of sedation or psychomotor performance was observed on negative symptoms.
  
  
  CONCLUSIONS
  Single doses of both haloperidol and risperidone induced nonmotor secondary negative symptoms in healthy volunteers. The clinical findings are especially relevant in view of the impact of negative symptoms on poor functioning. They may help to guide clinicians in their choice of APs (http://clinicaltrials.gov/ct2/show/NCT01259973).
authors: Department of Pathological Anatomy, Pharmacology and Microbiology, School of Medicine, University of Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain.
authors: Sergi
authors: S
authors: Mas
authors: Patricia
authors: P
authors: Gassó
authors: Ramón
authors: R
authors: Fernández de Bobadilla
authors: Joan Albert
authors: JA
authors: Arnaiz
authors: Miquel
authors: M
authors: Bernardo
authors: Amalia
authors: A
authors: Lafuente
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects*; D003342:Corpus Striatum / Q000378:metabolism; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006220:Haloperidol / Q000009:adverse effects*; D006801:Humans; D008297:Male; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D018967:Risperidone / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D017448:Receptors, Dopamine D2; D006220:Haloperidol; D018967:Risperidone
keywords: haloperidol; healthy volunteers; negative symptoms; randomized clinical trial; risperidone