Why M3 works

The M3 Checklist — one page, four conditions

The M3 Checklist is a 27-item, self-rated screening tool that assesses depression, bipolar spectrum, anxiety, and post-traumatic stress disorders together, in a single one-page instrument. Most published depression screens (like the PHQ-9) capture only one of these four — which means much of diagnosable mental illness can go undetected when only depression is screened for.

• Gateway-driven scoring. Four functional-impairment questions come first; deeper symptom scoring runs only for those who flag impairment — efficient without losing accuracy.
• Practical in real clinics. Patients finished it in under 5 minutes in the waiting room; 83% of clinicians reviewed it in 30 seconds or less, and 80% found it helpful for understanding emotional health.
• Catches bipolar disorder. About 10% of patients screened had bipolar disorder — missing it and starting an antidepressant alone can destabilize a patient. The M3 screens for it explicitly.
• Catches PTSD and anxiety too. Coexisting anxiety makes depression more treatment-resistant; the M3 covers all four common categories on one page.

The instrument: three questions, one number

Chronic pain and mental health travel together — an NIH-supported study published in the journal PAIN found that adults living with chronic pain are about five times more likely to report symptoms of anxiety or depression. Each feeds the other: pain disturbs sleep and mood; anxiety and low mood amplify pain. That is why the M3 review measures pain on the same dated record as mood, anxiety, trauma, and bipolar symptoms — and returns it as its own score, separate from the mental health score.

The PEG is a three-item scale for tracking chronic pain, developed by Krebs and colleagues at the VA and Indiana University and validated in the Journal of General Internal Medicine in 2009. Its name is its structure — Pain, Enjoyment, General activity. Each item is rated 0 to 10 for the past week:

Scoring. Add the three numbers and divide by three. The result is a single average from 0 to 10; higher means greater severity and greater interference with daily life. No cut-off is applied and none is needed — the PEG is here to be compared with itself. What matters is the direction from one review to the next.