title: Cognitive impairment in studies of 5HTTLPR and psychosis in Alzheimer's disease: a systematic review.
abstract: OBJECTIVE
  Cognitive impairment is a well-established correlate of psychotic symptoms in Alzheimer's disease (AD-P). We review whether this relationship has confounded previous genetic association studies of 5HTTLPR and AD-P.
  
  
  METHODS
  We reviewed all studies on 5HTTLPR and conducted a semi-quantitative analysis.
  
  
  RESULTS
  Three out of 4 studies with low MMSE reported a significant association, while 1 out of 4 with high MMSE reported a significant association.
  
  
  CONCLUSIONS
  Variation in cognitive impairment in past studies has contributed to the inconsistency in findings. The findings presented here bring a greater clarity to our understanding of the role of 5HTTLPR in AD-P.
authors: Wolfson Centre for Age-Related Diseases, King's College London, London, UK.
authors: Byron
authors: B
authors: Creese
authors: Clive
authors: C
authors: Ballard
authors: Emma
authors: E
authors: Jones
mesh_terms: D000544:Alzheimer Disease / Q000235:genetics* / Q000523:psychology*; D003702:Delusions / Q000235:genetics; D020022:Genetic Predisposition to Disease; D006212:Hallucinations / Q000235:genetics; D006801:Humans; D011110:Polymorphism, Genetic; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000209:etiology*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D012720:Severity of Illness Index
chemical_list: D050486:Serotonin Plasma Membrane Transport Proteins