The purpose of this study is to determine whether 75 mg amitriptyline affect the sleep dependent consolidation of procedural memory (visual discrimination task, Karni-Sagi-paradigm).

Rapid eye movement (REM) sleep is considered critical to the consolidation of procedural memory - the memory of skills and habits. Many antidepressants strongly suppress REM sleep, however, and procedural memory consolidation has been shown to be impaired in depressed patients on antidepressant therapy. As a result, it is important to determine whether antidepressive therapy can lead to amnestic impairment. We thus investigate the effects of the anticholinergic antidepressant amitriptyline on sleep-dependent memory consolidation in 32 healthy men in a double-blind, placebo-controlled, randomized parallel-group study.

Inclusion Criteria:

• male gender
• age 18 through 40 years
• ability to communicate effectively in German

Exclusion Criteria:

• shift work within the past 24 months
• any sleep disorder as measured by the Pittsburgh Sleep Quality Index
• irregular sleep/wake patterns or extreme chronotype as measured by the Morningness-Eveningness Questionnaire
• history of any neurologic or psychiatric disorders
• regular medication intake within the past four weeks
• contraindications for amitriptyline
• abnormal electrocardiogram (ECG)