Single Session Pain Psychology Treatment: Comparative Efficacy & Mechanisms

Inclusion Criteria:

* Axial low back pain without radicular symptoms
* Pain duration ≥ 6 months (per recent NIH Task Force on Research Standards for Chronic Low Back Pain based on participant self-report
* Average pain intensity ≥4/10 for the past month at screening visit
* English fluency
* Males and females 18-70 years of age
* Pain Catastrophizing Score (PCS) ≥20

Exclusion Criteria:

* Gross cognitive impairment
* Active suicidal ideation or severe depression
* Previous attendance in the active treatment groups (any ER classes ever taken or CBT in the past 3 years)
* Participating in any interventional research study or completed participation in the last 2 months; enrollment in an observational study is acceptable
* Current substance abuse
* Clear likelihood to disrupt fellow class participants (e.g., personality disorder) at the discretion of the study team