Behavioral and Neural Phenotypes of Primary Dysmenorrhea in Adolescents
Behavioral and Neural Phenotypes of Primary Dysmenorrhea in Adolescents
The study will use primary dysmenorrhea (PD; menstrual pain without an identified organic
 cause) as a model to examine biomarkers associated with menstrual and non-menstrual bodily
 pain in adolescent girls, ages 14-18. Participants will undergo extensive phenotyping
 including pain inhibition testing and multimodal neuroimaging to obtain indices brain
 structure and function at baseline and 12 months later. Menstrual pain severity and
 non-menstrual bodily pain will be assessed monthly for 24 months. Aims of the study are: 1)
 to identify the central mechanisms of PD using measures of pain inhibition and brain
 structure and connectivity of sensorimotor, default, emotional arousal, and salience
 networks, 2) to determine deficits in pain inhibition and alterations in brain structure and
 network connectivity that predict the one-year developmental trajectories of menstrual pain
 and non-menstrual bodily pain, and 3) to identify the dynamic relationship between
 alterations in pain inhibition and brain structure and connectivity with symptom change in
 menstrual pain and non-menstrual bodily pain. We hypothesize that deficits in endogenous pain
 inhibition and alterations in brain structure, connectivity, and function of regional
 networks will be positively associated with menstrual pain severity ratings at baseline and
 predict the trajectory of menstrual and non-menstrual bodily pain over 2 years. The results
 are expected to identify specific mechanisms and characteristics that predict the transition
 from acute/cyclical pain to persistent or chronic pain, which will support the development of
 therapies to prevent the transition from recurrent to chronic pain in adulthood.
Inclusion Criteria:

 1. Female aged 14-18 years

 2. Self-reported menstrual cycle averaging 22-35 days

 3. Access to a smartphone or email

 4. Right handed

 5. Body Mass Index (BMI) of 35 or less

 6. Able to read and understand English

 7. Ability and willingness to provide written informed assent/consent

 8. Availability of a parent to provide written parental permission (for participants
 under age 18)

 Exclusion Criteria:

 1. Use of oral contraceptives or any exogenous hormones in the previous 3 months prior to
 participation

 2. Presence of factors indicative of secondary dysmenorrhea (e.g., self-reported presence
 of persistent pelvic pain throughout the month)

 3. Diagnosis of chronic pain condition (e.g., Irritable bowel syndrome (IBS), functional
 abdominal pain, interstitial cystitis/painful bladder syndrome)

 4. Current self-reported severe depression, bipolar disorder, panic disorder, or ADHD, or
 current treatment for these conditions

 5. Diagnosis of an eating disorder within the last 6 months

 6. Current or past diagnosis of any psychotic disorder

 7. Currently pregnant

 8. Self-reported weekly use of alcohol, cannabis, and/or other illegal substances

 9. Use of stimulants (including methamphetamine and/or medications for the treatment of
 ADHD) or opioids in the previous 3 months. Participants who use other analgesics will
 be included but will be requested to not take these analgesics within the previous 24
 hours of the laboratory session

 10. History of pelvic inflammatory disease or sexually transmitted disease

 11. Acute illness or injury that would potentially impact pain task performance (e.g.,
 fever, flu symptoms) or that affect sensitivity of the extremities (e.g., Reynaud's
 disease). Potential participants who are being treated for cardiovascular disease(s)
 will be included pending discussion with the participant's primary physician

 12. Developmental delay, diagnosis of autism, or significant cognitive impairment that may
 preclude understanding of study procedures

 13. Presence of any ferromagnetic appliance or implants (braces, retainers, spacers,
 wires, screws, etc.) in the mouth or any other body part, which is a contraindication
 for the magnetic resonance imaging (MRI) scanner

 14. Significant fear of enclosed places (claustrophobia)