Alprazolam and lorazepam effects on memory acquisition and retrieval processes

Area of Science:

• Psychopharmacology
• Cognitive Neuroscience

Background:

• Benzodiazepines are commonly prescribed for anxiety and insomnia.
• Their effects on memory, particularly long-term memory acquisition versus retrieval, are not fully understood.

Purpose of the Study:

• To investigate the acute effects of alprazolam and lorazepam on long-term memory acquisition and retrieval.
• To compare the memory-impairing effects of these two benzodiazepines.

Main Methods:

• A double-blind study with healthy young adult males.
• Utilized Buschke's "selective reminding" task and a free recall task to assess memory.
• Administered alprazolam (1 mg) and lorazepam (2 mg), with assessments at baseline and hourly for 4 hours post-ingestion.
• Included psychomotor tests and subjective sedation ratings.

Main Results:

• Both benzodiazepines caused significant memory impairment, affecting both acquisition and retrieval.
• Benzodiazepine-induced memory deficits worsened over successive trials.
• Recall superiority of high-imagery words over low-imagery words was diminished.
• Psychomotor performance was impaired, and subjective sedation increased.
• Alprazolam and lorazepam produced comparable overall impairment, though alprazolam showed earlier onset and recovery.

Conclusions:

• Contrary to some views, benzodiazepines impair both memory acquisition and retrieval.
• The findings highlight the broad cognitive impact of these drugs, affecting memory and psychomotor function.
• Alprazolam and lorazepam demonstrate similar memory-impairing potential in healthy young males.