Stress is important for health. As emergency departments (EDs) are often stressful places, a better understanding of the human stress response is important for understanding how and why patients respond as they do when they come to the ED. Since the investigators cannot take up space in the ED for research, the investigators will instead recruit 20 methamphetamine-using participants who are not currently in treatment and 10 healthy adult matched participants to a simulated ED room in the University of Arkansas for Medical Sciences (UAMS) Simulation Center. The investigators will have participants perform a stressor task involving public speaking and a simple arithmetic task. The investigators will see if this experiment can be made to be like being in an actual ED by varying what participants speak about in the task. By doing this, the investigators hope to find out several important things: 1) Is a stressor task feasible and acceptable to participants? 2) What does the stress response -- as measured by cortisol and alpha-amylase -- look like in these participants? 3) Does varying what participants talk about make the experiment seem more like an actual ED? 4) Do participants under stress show even mild symptoms of agitation as measured by clinical scales? If so, how often?

Aim 1: Determine the feasibility and acceptability of an ED-relevant stressor task as compared to a standard social stressor task. The investigators hypothesize that an ED-relevant stressor task will be feasible, as measured by the ability to recruit/randomize/retain participants, and as acceptable to participants as a standard social stressor task.

Aim 2: Measure the stress response (alpha-amylase, cortisol, vital signs) in participants who undergo an ED-relevant stress task compared to a standard social stress task. The investigators hypothesize that norepinephrine release will be adequately assessed by salivary alpha-amylase and that an ED-relevant stressor task will elicit similar or greater physiological responses as a standard social stress task.

Aim 3: Evaluate the ED-representativeness of an ED-relevant stressor task compared to a standard social stressor task. Although both tasks will be performed in a simulated ED room in the UAMS Simulation Center, the investigators hypothesize that an ED-relevant task will be rated as more representative of an actual ED visit.

Aim 4: Evaluate ethological ratings of non-verbal behavior thought to indicate assertion and ratings of agitation using rating scales commonly employed in the clinical environment for this purpose. Participants undergoing stress sometimes display symptoms of assertion or agitation, but it is unknown when or how often this occurs. The investigators hypothesize that ethological ratings will be correlated with agitation scale scores and physiological changes.

Inclusion Criteria:

• Healthy adult
• 21-55 years of age
• Self-reported recent history of meth use that meets DSM-5 criteria for current meth use disorder
• Have been previously inside an ED as either a patient or visitor
• Able to construct a stressful mental script of ED experiences
• Body mass index (BMI) < 30
• Ability to read and understand English
• If matched control, no lifetime history of any recreational or non-prescribed drug use.

Exclusion Criteria:

• Eating/drinking/taking drugs or alcohol the morning before the experiment
• If smoker, not smoking the morning before the experiment
• Subjective or objective signs of intoxication or withdrawal from any substance
• History of any serious medical condition such as cardiovascular, endocrine, neurologic (seizures), or hepatic disease
• Pregnancy
• History of any mental illness
• Hypertensive (>150/90) or abnormal EKG at screening
• Use of any daily medication
• Any recent night shift work in the last 4 weeks
• Any travel across time zones in the last 14 weeks
• Participation in a similar study in the past year
• Refusal to allow videotaping