Olanzapine does not enhance cognition in non-agitated and non-psychotic patients with mild to moderate Alzheimer's dementia

Int J Geriatr Psychiatry. 2005 Nov;20(11):1020-7. doi: 10.1002/gps.1397.


Objective: This was an exploratory study of olanzapine as potential treatment for improvement in cognition in patients with Alzheimer's disease without prominent psychobehavioral symptoms.

Methods: Non-psychotic/non-agitated patients (n = 268) with Alzheimer's disease, who had baseline Mini-Mental State Examination (MMSE) scores of 14-26 were randomized to treatment with olanzapine (2.5 to 7.5 mg/d) or placebo for 26 weeks. The primary objectives were to determine if treatment with olanzapine improved cognition as indexed by the Alzheimer's disease Assessment Scale for Cognition (ADAS-Cog) and the Clinician's Interview-Based Impression of Change (CIBIC) after 26 weeks of therapy.

Results: Patients treated with olanzapine vs placebo experienced significant worsening ADAS-Cog scores at weeks 12 (p = 0.03) and 26 (p = 0.004). Changes in CIBIC scores were not significantly different between treatment groups at either assessment. A post hoc analysis revealed that olanzapine-treated patients with more cognitive impairment at baseline (MMSE scores of 14-18) (n = 35) experienced significantly greater deterioration in ADAS-Cog performance than patients in the placebo group (n = 24; p < 0.001); whereas in patients with less cognitive impairment (n = 78, baseline MMSE scores of 23-26) between-group ADAS-Cog changes were not significant.

Conclusions: In this 26-week study non-psychotic/non-agitated patients with Alzheimer's disease treated with olanzapine experienced significant worsening of cognition as compared to placebo.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / drug therapy
  • Alzheimer Disease / psychology*
  • Antipsychotic Agents / adverse effects
  • Antipsychotic Agents / therapeutic use*
  • Benzodiazepines / adverse effects
  • Benzodiazepines / therapeutic use
  • Cognition Disorders / drug therapy*
  • Cognition Disorders / etiology
  • Disease Progression
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neuropsychological Tests
  • Olanzapine
  • Prospective Studies
  • Psychiatric Status Rating Scales
  • Psychomotor Agitation
  • Treatment Outcome


  • Antipsychotic Agents
  • Benzodiazepines
  • Olanzapine