Q1
PHQ-9 trajectory across Neurocognitive brackets in major depressive disorder.
Hypothesis
In adults with newly-diagnosed MDD, baseline Neurocognitive (NM) axis bracket predicts PHQ-9 trajectory at 12 weeks independent of antidepressant class.
Cohort
Adults ≥18 with first MDD diagnosis (ICD-10 F32.x / F33.x) within the platform window, ≥1 PHQ-9 administration within ±30d of dx, ≥1 PHQ-9 at 12 weeks ±14d. n = 612 across all CH primary-care + behavioral surfaces.
Cohort filters
F32.* / F33.*
PHQ-9 baseline + 12w
NM axis · daily
Adults ≥18
Code
-- Cohort: first MDD + paired PHQ-9 WITH mdd AS ( SELECT person_id, MIN(condition_start_date) AS dx FROM omop.condition_occurrence WHERE condition_concept_id IN (4252191, 4262111) -- F32, F33 AND person_age >= 18 GROUP BY person_id ), phq AS ( SELECT person_id, observation_date, CAST(value_as_string AS int) AS phq9 FROM omop.observation WHERE observation_concept_id = 3022875 -- PHQ-9 total ), paired AS ( SELECT m.person_id, AVG(CASE WHEN ABS(p.observation_date - m.dx) <= 30 THEN phq9 END) AS phq_0, AVG(CASE WHEN ABS(p.observation_date - (m.dx + 84)) <= 14 THEN phq9 END) AS phq_12 FROM mdd m JOIN phq p USING (person_id) GROUP BY m.person_id ), nm AS ( -- CH extension: 8-axis daily telemetry, baseline window SELECT person_id, AVG(score) AS nm_avg FROM ch.axis_daily a JOIN mdd m USING (person_id) WHERE axis = 'NM' AND date BETWEEN m.dx - 30 AND m.dx GROUP BY person_id ) SELECT ch_bracket(nm_avg) AS nm_bracket, AVG(phq_0 - phq_12) AS phq_drop, k_anon(person_id, 11) AS n FROM paired JOIN nm USING (person_id) WHERE phq_0 IS NOT NULL AND phq_12 IS NOT NULL GROUP BY nm_bracket;
Result (mock)
| NM bracket (baseline) | Mean PHQ-9 drop, 0→12w | n |
|---|---|---|
| Excellent (8) | −7.4 | 61 |
| Very good (7) | −6.8 | 98 |
| Good (6) | −5.9 | 132 |
| Average (5) | −4.7 | 148 |
| Below avg (4) | −3.2 | 102 |
| Poor (3) | −1.9 | 71 |
Ethical guardrails
k-anonymity ≥ 11 enforced at output. PHQ-9 individual scores never leave the enclave. Antidepressant class as covariate available; medication-naive patients counted separately.