The purpose of the study is to determine the effects of AZD6280 compared to lorazepam on sleepiness, concentration and brain activity.

Inclusion Criteria:

• Healthy male and female subjects aged 18 to 55 years (inclusive) on Day 1.
• Female subjects must be of non-child bearing potential.

Exclusion Criteria:

• Clinically significant illness within 2 weeks before the study start.
• Enrollment in another concurrent investigational study or intake of an investigational drug within 30 days or intake of an investigational drug within a period of 5 half lives of that drug prior to the screening visit
• Blood loss in excess of 200 mL within 30 days of Day -2, in excess of 400 mL within 90 days of Day -2, or in excess of 1200 mL within 1 year of Day -2
• Clinically relevant abnormalities in physical examinations, vital signs, ECG, clinical chemistry, hematology or urinalysis