The Fear F8ctor Study - Does Fear Induce a Blood Curdling State?
Condition: Blood Coagulation Disorder
MeSH terms: Hemostatic Disorders; Blood Coagulation Disorders
Study type: Interventional

Summary: 
      For centuries the term "blood curling" has been used to describe extreme frightening
      situations. However, the origin of this ancient theory has never been studied and it remains
      unknown if fear induces the coagulation system.The objective was to explore the effects of
      acute fear on the coagulation system while sitting still. In a crossover study design healthy
      subjects will be exposed to a horrifying e.g. scary movie followed by a dull e.g. flat movie
      which is shown at least 1 week after the first movie on the same day of the week at the same
      time of the day. Participants will be recruited among students from the Leiden University
      Medical Center. Blood will be drawn from the cubital vein 10 minutes before the first movie,
      directly after the first movie. The same will be done 10 minutes before and directly after
      the second movie. Blood is drawn by using a needle puncture.

      Individual markers of coagulation activity will be determined from the blood samples. Pulse
      rates will be measured and an anxiety/fear score will be collected from each student for both
      movies.
    

Detailed description: 
      Rationale: For centuries the term "blood curling" has been used to describe extreme
      frightening situations. The term dates back to the medieval physiology, it was believed that
      the human body contained four chief fluids, blood, phlegm, bile and black bile. It was
      thought that fear or horror would 'run the blood cold' or 'curdle' (solidify). To date large
      parts of the complex mechanism of the coagulation cascade have been unravelled and many risk
      factors for clotting, i.e., thrombosis have been identified. However, the origin of this
      ancient theory has never been studied and it remains unknown if fear induces the coagulation
      system.

      Objective: To explore the effects of acute fear on the coagulation system while sitting
      still.

      The investigators will compare systemic coagulation markers before and after both movies in
      each subject: 13 subjects will be exposed to the horrifying movie first, followed by the dull
      movie (at least 1 week later). Both movies will be shown on the same day of the week, at the
      same time of the day and will last approximately 90 minutes. One group of 13 will first view
      the horrifying movie, followed by the dull move the next week (Group I) and 13 subjects will
      be exposed to the dull movie first, followed by the horrifying movie (Group II). Spacious
      seats will be used to avoid the effect of immobilisation due to tight cinema seats. Blood is
      drawn at four time points (TP); (0) before the first movie (baseline), after the first movie
      (1), before the second movie (2) and after the second movie (3). A needle puncture is used to
      collect 12 ml of blood at each time point.

      Individual markers of coagulation activity will be determined from the blood samples. Pulse
      rates will be measured and an anxiety/fear score will be collected from each student for both
      movies.
    

Intervention name(s): Dull movie; Scary (horrifying) movie; Heart rate measurement
Intervention type(s): Other; Other; Other
Intervention description(s): A dull movie (duration approximately 90 minutes); A scary movie (duration approximately 90 minutes); Heart rate measurement using a actiheart device
Allocation: Non-Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)