Transmasculine youth (female sex assigned at birth, male gender identity) who begin clinical gender affirming hormone therapy (GAHT) with testosterone (T) may experience changes in headache. Researchers think this because studies published on effects of giving testosterone to cisgender females (female sex, female gender identity) and transmasculine adults seem to show an effect on pain.

This research will help us learn more about changes in headache and in brain structure and function in transmasculine youth during the first two years of T. Youth who will be starting T within 6 months, either on puberty blocker or not, as part of their regular medical care can participate and will be asked to attend 4 visits:

• before starting T
• after 6 months on T
• after 1 year on T
• after 2 years on T

At the visits, they will be asked to:

• answer questions and surveys about their health
• have a brain MRI done
• give a small sample of blood

and at their first visit, complete a physical exam. Some participants can also do a brief test of pain sensitivity. All participants will be asked to complete a headache diary for the first 6 months, for 1 month after the 1 year visit, and for 1 month after the 2 year visit.

This will be conducted at Childrens Hospital Colorado (CHCO) Clinical & Translational Research Centers (CTRC) facilities. Physical examination will include vital signs, anthropometric measurements, and breast/pubic hair staging, as applicable, by a medical provider.

Visits will be in the morning to capture peak hormone levels.

The following questionnaires will be administered: PROMIS Pediatric Anxiety Short Form, PROMIS Pediatric Depressive Symptoms Short Form, and PedMIDAS form (headache disability measure).

The daily headache diary is tailored to be brief on days when no headache occurs, and to capture more detail including medications taken and headache and aura characteristics on days a headache does occur.

The medical chart will be reviewed for relevant health information and medications.

MR-based imaging will be conducted at the Brain Imaging Center at the University of Colorado Anschutz Medical Campus.

Inclusion Criteria:

1. transmasculine and gender diverse
2. assigned female at birth
3. age 12-20 years at the time of enrollment
4. plan to start testosterone clinically in < 6 months
5. if taking gonadotropin releasing hormone agonist (GnRHa, puberty blocker), was started on this type of drug 3+ months prior to enrollment

Exclusion Criteria:

1. cognitive or psychiatric impairment resulting in inability to tolerate or perform the study procedures
2. known history of stroke, multiple sclerosis, or other serious neurologic condition
3. prior diagnosis of Turner Syndrome (monosomy X) or other difference of sexual development
4. prior diagnosis of polycystic ovarian syndrome (PCOS)
5. uncontrolled or untreated hypothyroidism
6. MRI-specific exclusion criteria: (Weight > 500 lbs, severe claustrophobia, certain type of metal in body)

Transmasculine, gender diverse

transmasculine and gender diverse youth