title: Inferring about individual drug and schizotypy effects on cognitive functioning in polydrug using mephedrone users before and after clubbing.
abstract: OBJECTIVE
  Mephedrone has been recently made illegal in Europe, but little empirical evidence is available on its impact on human cognitive functions. We investigated acute and chronic effects of mephedrone consumption on drug-sensitive cognitive measures, while also accounting for the influence of associated additional drug use and personality features.
  
  
  METHODS
  Twenty-six volunteers from the general population performed tasks measuring verbal learning, verbal fluency and cognitive flexibility before and after a potential drug-taking situation (pre-clubbing and post-clubbing at dance clubs, respectively). Participants also provided information on chronic and recent drug use, schizotypal (Oxford-Liverpool Inventory of Feelings and Experiences) and depressive symptoms (Beck Depression Inventory), sleep pattern and premorbid IQ.
  
  
  RESULTS
  We found that (i) mephedrone users performed worse than non-users pre-clubbing and deteriorated from the pre-clubbing to the post-clubbing assessment; (ii) pre-clubbing cannabis and amphetamine (not mephedrone) use predicted relative cognitive attenuations; (iii) post-clubbing, depression scores predicted relative cognitive attenuations; and (iv) schizotypy was largely unrelated to cognitive functioning, apart from a negative relationship between cognitive disorganisation and verbal fluency.
  
  
  CONCLUSIONS
  Results suggest that polydrug use and depressive symptoms in the general population negatively affect cognition. For schizotypy, only elevated cognitive disorganisation showed potential links to a pathological cognitive profile previously reported along the psychosis dimension.
authors.affiliation: Department of Experimental Psychology, University of Bristol, Bristol, UK. Daniela.Herzig@epfl.ch
authors.forename: Daniela A
authors.initials: DA
authors.lastname: Herzig
authors.forename: Rowan
authors.initials: R
authors.lastname: Brooks
authors.forename: Christine
authors.initials: C
authors.lastname: Mohr
mesh_terms: D000293:Adolescent; D000328:Adult; D003071:Cognition / Q000187:drug effects* / Q000502:physiology; D003072:Cognition Disorders / Q000139:chemically induced* / Q000175:diagnosis / Q000523:psychology; D003615:Dancing; D005260:Female; D006801:Humans; D013287:Illicit Drugs / Q000009:adverse effects*; D008297:Male; D008694:Methamphetamine / Q000009:adverse effects / Q000031:analogs & derivatives*; D011597:Psychomotor Performance / Q000187:drug effects* / Q000502:physiology; D012569:Schizotypal Personality Disorder / Q000139:chemically induced / Q000175:diagnosis / Q000523:psychology; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D013287:Illicit Drugs; D008694:Methamphetamine; C548233:mephedrone