Journaling Intervention for Temporomandibular Disorder (TMD) and Chronic Overlapping Pain

• Gratitude (Behavioral): Participants in this group will receive a gratitude journal where they will be asked to write down three things they are grateful for each day and reflect why they are grateful for these things. Journaling will take place from the comfort of their home on three days of their choice per week, for a total duration of two weeks.
• General Wellness (Other): Participants in this group will receive a general wellness journal where they will be asked to reflect on three things that happened, or they did during the day (daily activities). Journaling will take place from the comfort of their home on three days of their choice per week, for a total duration of two weeks.

Primary outcomes

• Participant Retention [Baseline to Week 4]: Percentage of participants who initiate treatment/intervention and complete the post-intervention assessment at the 4-week time-point.
• Treatment Satisfaction [Week 4]: Single-item Treatment Satisfaction Questionnaire: Response to self-reported item assessing overall satisfaction with the treatment. The item is rated on a 1 to 4 scale (1 = Quite Dissatisfied to 4 = Very Satisfied) with the mean value calculated. A higher score indicates greater satisfaction with the treatment.

Secondary outcomes

• Pain Intensity [Baseline, Week 4]: The PROMIS-Pain Intensity short form is a 3-item measure assessing pain intensity over the past 7 days (i.e., "how intense was your pain at its worst"), as well as current level of pain. The total score for the PROMIS Pain Intensity short form will be calculated by summing the numerical values of the responses to each of the three items. After obtaining the total raw score, it will then be converted into a T-score, which standardizes the score with a mean of 50 and a standard deviation of 10, based on the general U.S. population.
• Pain Interference [Baseline, Week 4]: The PROMIS-Pain Interference short form is an 8-item measure assessing the extent to which pain interferes with physical, mental, cognitive, emotional, recreational and social activities over the past 7 days (i.e., "how much did pain interfere with work around home"). The total score for the PROMIS-Pain Interference short form will be calculated by summing the numerical values of the responses to each of the eight items. After obtaining the total raw score, it will then be converted into a T-score, which standardizes the score with a mean of 50 and a standard deviation of 10, based on the general U.S. population.

Sex: All, ages: 18 Years to 80 Years

Inclusion Criteria:

* participants between the ages of 18 and 80
* pain in the temporomandibular (TMD) region (jaw and/or temple area)
* duration of pain is at least 3 months
* average pain score ≥4 on a 0-10 numerical rating scale over the past week
* have at least one additional chronic overlapping pain condition (COPC) including fibromyalgia, irritable bowel syndrome, migraine-type headache, tension-type headache, low back pain, interstitial cystitis/painful bladder syndrome or chronic prostatitis, myalgic encephalomyelitis/chronic fatigue syndrome, vulvodynia, and painful endometriosis.
* able to read, understand, and write in English.

Exclusion Criteria:

* history of TMD surgery
* neoplasm or injury/trauma to the TMD area
* cancer-related pain
* scheduled for any surgeries during the study time-frame
* current participation in another clinical trial or psychological treatment for any pain-related condition that would interfere with study outcomes
* pregnant or lactating
* severe motor impairments (e.g., muscular dystrophy)
* severe psychiatric conditions (e.g., uncontrolled mood disorders)
* severe neurological or cognitive impairments (e.g., uncontrolled Parkinson's disease)
* any other conditions that in the opinion of study investigators could make participation in the study unsafe
* use of opioids within 48 hours prior to laboratory visit