The Trier Social Stress Test: Protocol and Biological Consequences
The Trier Social Stress Test (TSST) is a standardized laboratory protocol designed to reliably induce psychological and physiological stress responses through social-evaluative threat and uncontrollability, with elevation of cortisol being the primary biological consequence.
Protocol of the TSST
The TSST follows a structured, step-by-step protocol:
Preparation Phase
- Participant is brought to a waiting room
- Baseline measurements are taken (cortisol, heart rate, subjective stress)
- Participant is informed they will need to deliver a speech
Anticipatory Phase (5-10 minutes)
- Participant is led to the test room
- Participant is informed they must prepare an impromptu 5-minute speech for a mock job interview
- They are given brief preparation time (typically 3-5 minutes)
- They are told their performance will be evaluated by a panel of judges
Performance Phase (10 minutes)
- Speech Task (5 minutes): The participant delivers their prepared speech in front of a panel of 2-3 judges (typically 2 men and 1 woman) who maintain neutral, non-responsive facial expressions
- The judges are trained to provide no positive feedback, maintain minimal eye contact, and appear evaluative
- If the participant finishes early, judges prompt them to continue with standardized responses
- Mental Arithmetic Task (5 minutes): Immediately following the speech, the participant performs a surprise mental arithmetic task (typically serial subtraction, such as counting backward from 1,022 by 13)
- When errors occur, the participant must restart from the beginning
Recovery Phase
- The participant is moved to a separate room
- Post-test measurements are taken at regular intervals
- Debriefing occurs after recovery measurements are complete
Primary Biological Consequences
The most significant and well-documented biological consequence of the TSST is activation of the hypothalamic-pituitary-adrenal (HPA) axis, resulting in:
Elevated cortisol levels: Cortisol typically peaks 10-30 minutes after stress onset 1, 2
Cardiovascular changes:
Subjective psychological responses:
- Increased perceived stress
- Elevated anxiety
- Heightened emotional insecurity
- These psychological responses during (not before or after) the test correlate with physiological stress markers 1
Clinical and Research Applications
The TSST has been widely used to:
- Study stress reactivity in various populations
- Investigate the relationship between stress and mental health conditions
- Examine the impact of stress on cognitive function
- Serve as an alternative to pharmacological probing of the hypothalamic-pituitary-thyroid (HPT) axis 3
Modern Adaptations
Several variations of the TSST have been developed:
- Semi-Virtual TSST (SV-TSST): Combines in-person experimenter with virtual judges via teleconference 4
- Virtual Reality TSST: Uses immersive VR technology to create a virtual audience 2
These adaptations maintain the effectiveness of the original protocol while offering advantages such as standardization, reduced personnel requirements, and enhanced social distancing capabilities.
Important Considerations
- The TSST reliably induces both psychological and physiological stress responses that mimic real-world social stressors 5
- The protocol must be carefully standardized to ensure reproducibility of results 6
- Measuring subjective stress during (not just before and after) the test provides more informative data 1
- The stress response typically habituates with repeated exposures, particularly for cortisol 2
The TSST remains one of the most effective and widely used laboratory protocols for studying the complex interplay between social-evaluative threat, psychological processes, and physiological stress responses.