Major Depression Inventory

MDI

Map 12 caller-assigned Bech 2001 MDI integers (0-5 over the last 2 weeks) to ten DSM-IV/ICD-10 symptom items (appetite and psychomotor are each the published max of their pair) and return the 0-50 total and whether it meets this paper's optimal cutoff of 26.

LIVE $0.005 USDC GET /api/calc/mdi

Markdown: /docs/mdi.md · Canonical: https://magentlab.com/docs/mdi

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

What it computes

When to use

When an agent has already assigned Bech 2001 MDI 0-5 integers for all 12 printed items and needs the published ten-item total and cutoff of 26, not a depression interview, PHQ-9, QIDS, or Hamilton depression.

When not to use

Not a medical device and not a depression diagnosis or treatment order.
magent does not administer a depression interview. Each of the 12 printed items is a caller-assigned integer 0-5 (0 at no time through 5 all the time, last 2 weeks). magent does not interpret the items.
This is Bech 2001 MDI only. Psychomotor is the maximum of restless and subdued; appetite is the maximum of reduced and increased appetite; the remaining eight items add as published. Total 0-50. magent does not score PHQ-9, QIDS, or Hamilton depression.
Bech 2001 estimated an optimal total-score cutoff of 26 and treated the total as a sufficient statistic. magent returns at_or_above_cutoff (score ≥26) only. It does not apply Olsen 2003 HAM-D mapped mild/moderate/severe bands, and it does not apply DSM-IV or ICD-10 diagnostic algorithms from this paper.

Formula

MDI = low_spirits + lost_interest + lack_of_energy + low_self_confidence + guilt + life_not_worth_living + concentration + max(restless, subdued) + sleep + max(reduced_appetite, increased_appetite); each caller-assigned 0-5; ten scored items; max 50; Bech 2001 optimal total-score cutoff 26

Citation

Title: The sensitivity and specificity of the Major Depression Inventory, using the Present State Examination as the index of diagnostic validity
Authors: Bech P, Rasmussen NA, Olsen LR, Noerholm V, Abildgaard W
Source: J Affect Disord. 2001;66(2-3):159-164
DOI: 10.1016/s0165-0327(00)00309-8

Worked example

All items 0

Given: concentration=0guilt=0increased_appetite=0lack_of_energy=0life_not_worth_living=0lost_interest=0low_self_confidence=0low_spirits=0reduced_appetite=0restless=0sleep=0subdued=0

Each scored item is 0 (psychomotor max 0, appetite max 0, remaining items 0)
Score = 0 (max 50); at_or_above_cutoff false (Bech 2001 cutoff is 26)

Appetite and psychomotor are the max of each pair

Given: concentration=0guilt=0increased_appetite=1lack_of_energy=0life_not_worth_living=0lost_interest=0low_self_confidence=0low_spirits=0reduced_appetite=3restless=2sleep=0subdued=5

psychomotor = max(2, 5) = 5 (not 2+5); appetite = max(3, 1) = 3 (not 3+1)
Remaining items 0; score = 8; at_or_above_cutoff false

Bech 2001 cutoff 26

Given: concentration=0guilt=5increased_appetite=0lack_of_energy=5life_not_worth_living=1lost_interest=5low_self_confidence=5low_spirits=5reduced_appetite=0restless=0sleep=0subdued=0

5 + 5 + 5 + 5 + 5 + 1 + 0 + max(0, 0) + 0 + max(0, 0) = 26
Score = 26 (max 50); at_or_above_cutoff true. No Olsen 2003 severity band.

Also searched as

MDI
Major Depression Inventory
Major Depression Index
Bech MDI
WHO MDI
MDI score
10-item MDI
Bech 2001 depression

Try

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

/api/calc/mdi?low_spirits=0&lost_interest=0&lack_of_energy=0&low_self_confidence=0&guilt=0&life_not_worth_living=0&concentration=0&restless=0&subdued=0&sleep=0&reduced_appetite=0&increased_appetite=0

Full URL: https://api.magentlab.com/api/calc/mdi?low_spirits=0&lost_interest=0&lack_of_energy=0&low_self_confidence=0&guilt=0&life_not_worth_living=0&concentration=0&restless=0&subdued=0&sleep=0&reduced_appetite=0&increased_appetite=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/mdi?low_spirits=0&lost_interest=0&lack_of_energy=0&low_self_confidence=0&guilt=0&life_not_worth_living=0&concentration=0&restless=0&subdued=0&sleep=0&reduced_appetite=0&increased_appetite=0"

Parameters

Name	Type	Required	Description
`low_spirits`	integer	required	Caller-assigned Bech 2001 MDI item 1 (integer 0-5): felt low in spirits or sad over the last 2 weeks (0 at no time, 1 some of the time, 2 slightly less than half of the time, 3 slightly more than half of the time, 4 most of the time, 5 all the time). Adds as published. magent does not interpret the item.
`lost_interest`	integer	required	Caller-assigned Bech 2001 MDI item 2 (integer 0-5): lost interest in daily activities. Adds as published. magent does not interpret the item.
`lack_of_energy`	integer	required	Caller-assigned Bech 2001 MDI item 3 (integer 0-5): lacking in energy and strength. Adds as published. magent does not interpret the item.
`low_self_confidence`	integer	required	Caller-assigned Bech 2001 MDI item 4 (integer 0-5): felt less self-confident. Adds as published. magent does not interpret the item.
`guilt`	integer	required	Caller-assigned Bech 2001 MDI item 5 (integer 0-5): bad conscience or feelings of guilt. Adds as published. magent does not interpret the item.
`life_not_worth_living`	integer	required	Caller-assigned Bech 2001 MDI item 6 (integer 0-5): felt that life was not worth living. Adds as published. magent does not interpret the item.
`concentration`	integer	required	Caller-assigned Bech 2001 MDI item 7 (integer 0-5): difficulty concentrating, for example when reading the newspaper or watching television. Adds as published. magent does not interpret the item.
`restless`	integer	required	Caller-assigned Bech 2001 MDI item 8a (integer 0-5): felt very restless. The psychomotor item is the maximum of restless and subdued, not the sum. magent does not interpret the item.
`subdued`	integer	required	Caller-assigned Bech 2001 MDI item 8b (integer 0-5): felt subdued or slowed down. The psychomotor item is the maximum of restless and subdued, not the sum. magent does not interpret the item.
`sleep`	integer	required	Caller-assigned Bech 2001 MDI item 9 (integer 0-5): trouble sleeping at night. Adds as published. magent does not interpret the item.
`reduced_appetite`	integer	required	Caller-assigned Bech 2001 MDI item 10a (integer 0-5): reduced appetite. The appetite item is the maximum of reduced_appetite and increased_appetite, not the sum. magent does not interpret the item.
`increased_appetite`	integer	required	Caller-assigned Bech 2001 MDI item 10b (integer 0-5): increased appetite. The appetite item is the maximum of reduced_appetite and increased_appetite, not the sum. 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/mdi 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": [
    {
      "concentration": "0",
      "guilt": "0",
      "increased_appetite": "0",
      "lack_of_energy": "0",
      "life_not_worth_living": "0",
      "lost_interest": "0",
      "low_self_confidence": "0",
      "low_spirits": "0",
      "reduced_appetite": "0",
      "restless": "0",
      "sleep": "0",
      "subdued": "0"
    },
    {
      "concentration": "0",
      "guilt": "0",
      "increased_appetite": "0",
      "lack_of_energy": "0",
      "life_not_worth_living": "0",
      "lost_interest": "0",
      "low_self_confidence": "0",
      "low_spirits": "0",
      "reduced_appetite": "0",
      "restless": "0",
      "sleep": "0",
      "subdued": "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/mdi",
  "items": [
    {
      "components": [
        {
          "value": 0,
          "factor": "low_spirits",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "lost_interest",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "lack_of_energy",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "low_self_confidence",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "guilt",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "life_not_worth_living",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "concentration",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "psychomotor",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "sleep",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "appetite",
          "points": 0,
          "present": true
        }
      ],
      "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": "Bech P, Rasmussen NA, Olsen LR, Noerholm V, Abildgaard W",
        "doi": "10.1016/s0165-0327(00)00309-8",
        "id": "bech-2001",
        "pmid": "11578668",
        "source": "J Affect Disord. 2001;66(2-3):159-164",
        "title": "The sensitivity and specificity of the Major Depression Inventory, using the Present State Examination as the index of diagnostic validity"
      },
      "formula": "mdi",
      "formula_expression": "MDI = low_spirits + lost_interest + lack_of_energy + low_self_confidence + guilt + life_not_worth_living + concentration + max(restless, subdued) + sleep + max(reduced_appetite, increased_appetite); each caller-assigned 0-5; ten scored items; max 50; Bech 2001 optimal total-score cutoff 26",
      "max_score": 50,
      "score": 0,
      "at_or_above_cutoff": false,
      "appetite_points": 0,
      "psychomotor_points": 0
    },
    {
      "components": [
        {
          "value": 0,
          "factor": "low_spirits",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "lost_interest",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "lack_of_energy",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "low_self_confidence",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "guilt",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "life_not_worth_living",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "concentration",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "psychomotor",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "sleep",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "appetite",
          "points": 0,
          "present": true
        }
      ],
      "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": "Bech P, Rasmussen NA, Olsen LR, Noerholm V, Abildgaard W",
        "doi": "10.1016/s0165-0327(00)00309-8",
        "id": "bech-2001",
        "pmid": "11578668",
        "source": "J Affect Disord. 2001;66(2-3):159-164",
        "title": "The sensitivity and specificity of the Major Depression Inventory, using the Present State Examination as the index of diagnostic validity"
      },
      "formula": "mdi",
      "formula_expression": "MDI = low_spirits + lost_interest + lack_of_energy + low_self_confidence + guilt + life_not_worth_living + concentration + max(restless, subdued) + sleep + max(reduced_appetite, increased_appetite); each caller-assigned 0-5; ten scored items; max 50; Bech 2001 optimal total-score cutoff 26",
      "max_score": 50,
      "score": 0,
      "at_or_above_cutoff": false,
      "appetite_points": 0,
      "psychomotor_points": 0
    }
  ]
}

Response

Field	Type	Description
`formula`	string	mdi
`formula_expression`	string	Exact expression used
`score`	integer	MDI points 0-50
`max_score`	integer	50
`at_or_above_cutoff`	boolean	true iff score ≥ 26 (Bech 2001 optimal total-score cutoff). Not a diagnosis. Not Olsen 2003 HAM-D mapped mild/moderate/severe bands.
`appetite_points`	integer	Appetite item 0-5: maximum of reduced_appetite and increased_appetite, not the sum
`psychomotor_points`	integer	Psychomotor item 0-5: maximum of restless and subdued, not the sum
`components`	array	Ten scored DSM-IV/ICD-10 symptom points
`citation`	object	Bech et al. J Affect Disord 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": "low_spirits",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "lost_interest",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "lack_of_energy",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "low_self_confidence",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "guilt",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "life_not_worth_living",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "concentration",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "psychomotor",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "sleep",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "appetite",
      "points": 0,
      "present": true
    }
  ],
  "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": "Bech P, Rasmussen NA, Olsen LR, Noerholm V, Abildgaard W",
    "doi": "10.1016/s0165-0327(00)00309-8",
    "id": "bech-2001",
    "pmid": "11578668",
    "source": "J Affect Disord. 2001;66(2-3):159-164",
    "title": "The sensitivity and specificity of the Major Depression Inventory, using the Present State Examination as the index of diagnostic validity"
  },
  "formula": "mdi",
  "formula_expression": "MDI = low_spirits + lost_interest + lack_of_energy + low_self_confidence + guilt + life_not_worth_living + concentration + max(restless, subdued) + sleep + max(reduced_appetite, increased_appetite); each caller-assigned 0-5; ten scored items; max 50; Bech 2001 optimal total-score cutoff 26",
  "max_score": 50,
  "score": 0,
  "at_or_above_cutoff": false,
  "appetite_points": 0,
  "psychomotor_points": 0
}

Client errors (HTTP 400)

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

HTTP	Code	When
400	`invalid_mdi`	Each Major Depression Inventory item must be an integer in the Bech 2001 published range. 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

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.
QIDS — Map 16 caller-assigned Rush 2003 QIDS-SR integers (0-3) to nine DSM-IV domains (sleep, appetite/weight, and psychomotor are each the published max of their items) and return the 0-27 total and IRT severity band.
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.

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. HTTP 402 never includes the tool JSON.
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.