MAGENT

Emergency · LIVE

PHQ-9

Sum nine caller-assigned Kroenke 2001 PHQ-9 integers (0-3) and return the published total (max 27), severity cutpoints, and ≥10 screen.

LIVE $0.005 USDC GET /api/calc/phq_9

Markdown: /docs/phq-9.md · Canonical: https://magentlab.com/docs/phq-9

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

Sum nine caller-assigned Kroenke 2001 PHQ-9 integers (0-3) and return the published total (max 27), severity cutpoints, and ≥10 screen.

When to use

When an agent has already assigned Kroenke 2001 0-3 integers for each of the nine PHQ-9 items and needs the published total, severity cutpoints, and ≥10 screen, not a depression diagnosis or GAD-7.

When not to use

  • Not a medical device and not a depression diagnosis or treatment order.
  • Each of the nine items is a caller-assigned integer 0-3 (0 not at all, 1 several days, 2 more than half the days, 3 nearly every day). magent does not interpret the items.
  • This is Kroenke 2001 PHQ-9 only (nine DSM-IV depression items; max 27). magent does not score PHQ-2, PHQ-8, or GAD-7.
  • Published severity cutpoints are 5 / 10 / 15 / 20 (0-4 none_minimal, 5-9 mild, 10-14 moderate, 15-19 moderately_severe, 20-27 severe). Score 0 is none_minimal; magent does not invent a separate none class. screen_ge_10 is true iff score ≥10 (this paper: 88% sensitivity and 88% specificity for major depression). It is a screen, not a diagnosis.

Formula

PHQ-9 = anhedonia + depressed + sleep + energy + appetite + failure + concentration + psychomotor + self_harm; each caller-assigned 0-3; max 27

Citation

Title
The PHQ-9: validity of a brief depression severity measure
Authors
Kroenke K, Spitzer RL, Williams JBW
Source
J Gen Intern Med. 2001;16(9):606-613
DOI
10.1046/j.1525-1497.2001.016009606.x

Worked example

All items 0

Given: anhedonia=0appetite=0concentration=0depressed=0energy=0failure=0psychomotor=0self_harm=0sleep=0

  1. anhedonia 0 + depressed 0 + sleep 0 + energy 0 + appetite 0 + failure 0 + concentration 0 + psychomotor 0 + self_harm 0
  2. Score = 0 (max 27); severity none_minimal; screen_ge_10 false

Five items 2

Given: anhedonia=2appetite=2concentration=0depressed=2energy=2failure=0psychomotor=0self_harm=0sleep=2

  1. Score = 10
  2. severity moderate; screen_ge_10 true (threshold is ≥10)

Also searched as

  • PHQ-9
  • PHQ9
  • Patient Health Questionnaire-9
  • Kroenke PHQ-9
  • depression severity measure
  • nine-item depression questionnaire
  • PHQ-9 score
  • DSM-IV PHQ-9

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/phq_9?anhedonia=0&depressed=0&sleep=0&energy=0&appetite=0&failure=0&concentration=0&psychomotor=0&self_harm=0

Full URL: https://api.magentlab.com/api/calc/phq_9?anhedonia=0&depressed=0&sleep=0&energy=0&appetite=0&failure=0&concentration=0&psychomotor=0&self_harm=0

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge. 

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/phq_9?anhedonia=0&depressed=0&sleep=0&energy=0&appetite=0&failure=0&concentration=0&psychomotor=0&self_harm=0"

Parameters

Name Type Required Description
anhedonia integer required Caller-assigned Kroenke 2001 PHQ-9 item 1 (integer 0-3): little interest or pleasure in doing things (0 not at all, 1 several days, 2 more than half the days, 3 nearly every day). magent does not interpret the item.
depressed integer required Caller-assigned Kroenke 2001 PHQ-9 item 2 (integer 0-3): feeling down, depressed, or hopeless. magent does not interpret the item.
sleep integer required Caller-assigned Kroenke 2001 PHQ-9 item 3 (integer 0-3): trouble falling or staying asleep, or sleeping too much. magent does not interpret the item.
energy integer required Caller-assigned Kroenke 2001 PHQ-9 item 4 (integer 0-3): feeling tired or having little energy. magent does not interpret the item.
appetite integer required Caller-assigned Kroenke 2001 PHQ-9 item 5 (integer 0-3): poor appetite or overeating. magent does not interpret the item.
failure integer required Caller-assigned Kroenke 2001 PHQ-9 item 6 (integer 0-3): feeling bad about yourself — a failure, or having let yourself or your family down. magent does not interpret the item.
concentration integer required Caller-assigned Kroenke 2001 PHQ-9 item 7 (integer 0-3): trouble concentrating on things such as reading or watching television. magent does not interpret the item.
psychomotor integer required Caller-assigned Kroenke 2001 PHQ-9 item 8 (integer 0-3): moving or speaking so slowly that other people could have noticed, or being so fidgety or restless that you have been moving around a lot more than usual. magent does not interpret the item.
self_harm integer required Caller-assigned Kroenke 2001 PHQ-9 item 9 (integer 0-3): thoughts that you would be better off dead, or of hurting yourself in some way. magent does not interpret the item.

Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

POST /api/calc/phq_9 Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 PREVIEW

  • 1 to 25 items. Each item uses the same keys as the GET query parameters.
  • POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
  • The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
  • HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
  • Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
  • x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "anhedonia": "0",
      "appetite": "0",
      "concentration": "0",
      "depressed": "0",
      "energy": "0",
      "failure": "0",
      "psychomotor": "0",
      "self_harm": "0",
      "sleep": "0"
    },
    {
      "anhedonia": "0",
      "appetite": "0",
      "concentration": "0",
      "depressed": "0",
      "energy": "0",
      "failure": "0",
      "psychomotor": "0",
      "self_harm": "0",
      "sleep": "0"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/phq_9",
  "items": [
    {
      "components": [
        {
          "value": 0,
          "factor": "anhedonia",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "depressed",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "sleep",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "energy",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "appetite",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "failure",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "concentration",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "psychomotor",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "self_harm",
          "points": 0,
          "present": true
        }
      ],
      "severity": "none_minimal",
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Kroenke K, Spitzer RL, Williams JBW",
        "doi": "10.1046/j.1525-1497.2001.016009606.x",
        "id": "kroenke-2001",
        "pmid": "11556941",
        "source": "J Gen Intern Med. 2001;16(9):606-613",
        "title": "The PHQ-9: validity of a brief depression severity measure"
      },
      "formula": "phq_9",
      "formula_expression": "PHQ-9 = anhedonia + depressed + sleep + energy + appetite + failure + concentration + psychomotor + self_harm; each caller-assigned 0-3; max 27",
      "max_score": 27,
      "score": 0,
      "screen_ge_10": false
    },
    {
      "components": [
        {
          "value": 0,
          "factor": "anhedonia",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "depressed",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "sleep",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "energy",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "appetite",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "failure",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "concentration",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "psychomotor",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "self_harm",
          "points": 0,
          "present": true
        }
      ],
      "severity": "none_minimal",
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Kroenke K, Spitzer RL, Williams JBW",
        "doi": "10.1046/j.1525-1497.2001.016009606.x",
        "id": "kroenke-2001",
        "pmid": "11556941",
        "source": "J Gen Intern Med. 2001;16(9):606-613",
        "title": "The PHQ-9: validity of a brief depression severity measure"
      },
      "formula": "phq_9",
      "formula_expression": "PHQ-9 = anhedonia + depressed + sleep + energy + appetite + failure + concentration + psychomotor + self_harm; each caller-assigned 0-3; max 27",
      "max_score": 27,
      "score": 0,
      "screen_ge_10": false
    }
  ]
}

Response

Field Type Description
formula string phq_9
formula_expression string Exact expression used
score integer PHQ-9 points 0-27
max_score integer 27
severity string Kroenke 2001 cutpoints: none_minimal (0-4), mild (5-9), moderate (10-14), moderately_severe (15-19), severe (20-27). Score 0 is none_minimal. Not a diagnosis.
screen_ge_10 boolean true iff score ≥ 10 (Kroenke 2001: score ≥10 sensitivity 88% and specificity 88% for major depression). Not a diagnosis.
components array Per-item caller-assigned points
citation object Kroenke et al. J Gen Intern Med 2001 citation
disclaimer string Not-a-device notice

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup. 

{
  "components": [
    {
      "value": 0,
      "factor": "anhedonia",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "depressed",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "sleep",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "energy",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "appetite",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "failure",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "concentration",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "psychomotor",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "self_harm",
      "points": 0,
      "present": true
    }
  ],
  "severity": "none_minimal",
  "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
  "citation": {
    "authors": "Kroenke K, Spitzer RL, Williams JBW",
    "doi": "10.1046/j.1525-1497.2001.016009606.x",
    "id": "kroenke-2001",
    "pmid": "11556941",
    "source": "J Gen Intern Med. 2001;16(9):606-613",
    "title": "The PHQ-9: validity of a brief depression severity measure"
  },
  "formula": "phq_9",
  "formula_expression": "PHQ-9 = anhedonia + depressed + sleep + energy + appetite + failure + concentration + psychomotor + self_harm; each caller-assigned 0-3; max 27",
  "max_score": 27,
  "score": 0,
  "screen_ge_10": false
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

HTTP Code When
400 invalid_phq9_item each PHQ-9 item must be an integer from 0 to 3 (Kroenke 2001: 0 not at all, 1 several days, 2 more than half the days, 3 nearly every day). Returned before settlement; you are not charged.
400 invalid_items POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
400 invalid_item_count items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
400 invalid_item each items entry must be a JSON object Returned before settlement; you are not charged.

Related tools

  • GAD-7 — Sum seven caller-assigned Spitzer 2006 GAD-7 integers (0-3) and return the published 0-21 total, 5/10/15 severity cuts, and ≥10 case-finding flag.
  • CAGE — Sum the four Ewing 1984 CAGE items and return whether two or more answers are affirmative.
  • AUDIT-C — Sum three caller-assigned Bush 1998 AUDIT-C integers (0-4) and return this paper's ≥3 and ≥4 screens.

Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

  • HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged.
  • exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
  • HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
  • Execution is timeout-bounded and concurrency-capped.
  • Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.