Depression Model

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1. Overview of the Model

This document describes the WHO - MSD - Depression model, which is a botech implementation of the Spectrum Depression Model.

The primary purpose of this model is to simulate the progression of depression within a population and to understand the potential impact of various interventions. It helps to model how an individual's health status regarding depression can change over time, moving between states such as being healthy, having a depression episode, receiving treatment, or recovering.

By simulating these processes, the model can assist decision-makers in understanding the potential effects of different health programs and interventions aimed at addressing depression. This can help in planning and allocating resources more effectively. The model runs from the year 2025 to 2050.

2. The Model's Building Blocks: Population Groups and How They Connect

The model is constructed from various components that represent different population segments, health states, and influential factors. These are connected to show how the population's health can change.

a. Population Groups and Key Factors (Nodes):

The model uses "states" or "groups" (called nodes) to represent different segments of the population or important factors that influence health.

Key population groups (STATE nodes) in this model include:

  • DsFreeSus: This group represents the healthy population, susceptible to developing depression but currently free of the disease.
  • DepressionEpsd: This group represents individuals who are currently experiencing a depression episode.
  • Deceased-DsFreeSus: This represents individuals from the "DsFreeSus" group who have passed away due to general mortality.
  • Deceased-DepressionEpsd: This represents individuals from the "DepressionEpsd" group who have passed away.
  • Healthy Years Lived: This is a special state that accumulates the healthy years lived by the population, considering the impact of disability.

Other important nodes represent fixed numbers, rates, or intermediate calculations:

  • CONSTANT nodes: These are fixed values or rates used as inputs. Examples include:

    • Depression_Disability_Weight: A fixed value representing the disability associated with a depression episode.
    • Healthy_Disability_Weight: A fixed value representing the disability for the healthy population (typically zero).
    • DepressionEpsd_Incidence_Rate: The baseline rate at which new cases of depression appear in the healthy population, based on data for the specified country and condition.
    • DepressionEpsd_Remission: The baseline rate at which individuals with a depression episode recover, based on data for the specified country and condition.
    • DepressionEpsd_CFR: The Case Fatality Rate for depression episodes.
    • AntiDepressantBasicPsychMild_Disability_Impact: The reduction in disability due to the "Basic psychosocial treatment for mild depression" intervention. Similar nodes exist for other interventions and their impact on disability (_Disability_Impact), remission (_Remission_Impact), or incidence (_Incidence_Impact).
    • AntiDepressantBasicPsychMild_Coverage: The proportion of the eligible population reached by the "Basic psychosocial treatment for mild depression" intervention. This can change over time. Similar nodes exist for other interventions.
    • Adherence parameters (e.g., AntiDepressantBasicPsychMild-Adherence).

  • SURROGATE nodes: These are temporary holding places for calculations that help the model progress. For example:

    • DepressionEpsd Incidence: A temporary store for the number of new depression cases calculated in a time step before they are added to the "DepressionEpsd" group.
    • DepressionEpsd Remission: A temporary store for the number of people recovering from depression in a time step.
    • DepressionEpsd Mortality: A temporary store for calculations related to deaths from depression episodes.
    • DsFreeSus HYL: A temporary calculation for the healthy years lived by the "DsFreeSus" group.

  • FUNCTION nodes: These nodes perform calculations based on their inputs. Examples include:

    • Combined_HYL: Calculates the overall health-adjusted life years, considering disability weights and intervention effects.
    • Disability_Effect_Transform: Calculates the combined effect of interventions on reducing disability.
    • Remission_Effect_Transform: Calculates the combined effect of interventions on increasing remission.
    • Incidence_Effect_Transform: Calculates the combined effect of interventions on reducing incidence (for relevant interventions).
    • Births: Stores the number of births occurring in the population during a time step.

b. Connections and Movements (Links):

"Links" show how people move between population groups or how factors influence each other.

Key connections in the model include:

  • Population Dynamics:

    • DsFreeSus -> Births and DepressionEpsd -> Births: These links calculate the number of births from individuals in the "DsFreeSus" (healthy) and "DepressionEpsd" groups, respectively. This is based on fertility rates from the specified country. The total births are stored in the "Births" node.
    • Births -> DsFreeSus: New male and female births are added to the "DsFreeSus" (healthy) population group. This uses sex ratio data for the specified country.
    • Migration - DsFreeSus and Migration - DepressionEpsd: These links adjust the number of people in the "DsFreeSus" and "DepressionEpsd" groups to account for people moving into or out of the area, based on national migration data.
    • BackgroundMortality DsFreeSus (DsFreeSus -> Deceased-DsFreeSus) and Background Mortality DepressionEpsd (DepressionEpsd -> Deceased-DepressionEpsd): These links move individuals from the "DsFreeSus" and "DepressionEpsd" groups to their respective "Deceased" states. This movement is based on general death rates obtained for the specified country. People are removed from the source group.

  • Depression Progression and Recovery:

    • Prevalence DsFreeSus -> DepressionEpsd: This link represents the initial allocation of the population into the "DepressionEpsd" state based on existing prevalence data for the specified country and condition. People are moved out of "DsFreeSus".
    • DepressionEpsd_Incidence_Rate influences DepressionEpsd Incidence -> DepressionEpsd: New cases of depression arise from the "DsFreeSus" group and move to the "DepressionEpsd" group. The rate is determined by DepressionEpsd_Incidence_Rate and can be modified by intervention effects on incidence.
    • DepressionEpsd_Remission rate influences DepressionEpsd Remission -> DsFreeSus: Individuals in the "DepressionEpsd" group can recover and move back to the "DsFreeSus" group. The base rate is determined by DepressionEpsd_Remission and can be modified by intervention effects on remission.
    • DepressionEpsd_CFR influences Case Fatality DepressionEpsd (DepressionEpsd -> Deceased-DepressionEpsd): This pathway represents deaths due to depression, using the Case Fatality Rate.

  • Intervention Effects on Disability, Remission, and Incidence: The model includes several interventions (detailed in Section 4).

    • Links like AntiDepressantBasicPsychMild_Disability_Impact -> AntiDepressantBasicPsychMild_Disability_Effect: The inherent disability reduction efficacy of an intervention is combined with its coverage (AntiDepressantBasicPsychMild_Calculated_Coverage) and population in need (AntiDepressantBasicPsychMild_PIN) to determine the overall AntiDepressantBasicPsychMild_Disability_Effect. This effect then influences the Combined_DW (Combined Disability Weight). Adherence (e.g., AntiDepressantBasicPsychMild-Adherence -> AntiDepressantBasicPsychMild_Disability_Impact) also modifies the intervention's impact.
    • Similar links exist for remission effects (e.g., _Remission_Impact -> _Remission_Effect) which modify the DepressionEpsd Remission rate via Remission_Effect_Transform.
    • For Intervention 5 (maintenance treatment), _Incidence_Impact -> _Incidence_Effect links modify the DepressionEpsd Incidence rate via Incidence_Effect_Transform.
    • These effects are aggregated in their respective _Effect_Transform nodes.

  • Calculating Health Outcomes (DALYs, HYL):

    • Depression_Disability_Weight and Healthy_Disability_Weight are used in HYL calculations.
    • DsFreeSus HYL and DepressionEpsd HYL (potentially Modified_HYL after intervention effects) contribute to the "Healthy Years Lived" state.
    • Years of Life Lost (YLLs) are calculated when individuals move to Deceased-DsFreeSus (recorded as YLL-DsFreeSus) or Deceased-DepressionEpsd (recorded as YLL-DepressionEpsd).
    • Years Lived with Disability (YLDs) are calculated for DepressionEpsd (recorded as YLD-DepressionEpsd, based on Combined_DW).
    • DALYs (Disability-Adjusted Life Years) are then calculated by summing the relevant YLL and YLD components into a "DALYs" node.

  • Resource Utilization:

    • Links like PopulationReached-AntiDepressantBasicPsychMild -> [Resource Node]: When individuals receive an intervention (represented by "PopulationReached" nodes), this triggers resource use. The model calculates demand for personnel time, medicines, and visits, which are then translated into costs.

This structure allows the model to simulate how the population moves between health states, how interventions affect these transitions and outcomes, and what resources are consumed.

3. How the Model Simulates Changes Over Time (Subroutines)

The model simulates changes year by year (or for other defined time periods) by following a sequence of steps, called "subroutines." Here's what happens in each main step:

  • Flush unneeded values: This step resets or clears out temporary values from the previous time period to prepare for new calculations.
  • Generate the population: This step sets up the initial numbers of people in the main healthy population group ("DsFreeSus") at the beginning of a time period.
  • Allocate prevalence: This step distributes the initial population into the "DepressionEpsd" state based on existing disease prevalence at the start of the simulation (for the first year) or adjusts based on incidence in subsequent years.
  • Generate the base values of the surrogate nodes: Calculates starting values for temporary holding places used in calculations (e.g., for new cases, remissions, HYL contributions, mortality).
  • Generate the base values of the function nodes for constants: Sets up initial values for nodes that perform calculations based on other inputs.
  • Generate the values of the constants: Loads or calculates fixed input values like disability weights, baseline incidence/remission rates, CFR, and intervention characteristics (coverage, efficacy).
  • Modify the impact (efficacy) by the adherence: Adjusts the effectiveness of interventions based on how well people adhere to treatment.
  • Calculate the Incidence Surrogate: Computes the number of new depression cases based on the incidence rate.
  • Calculate the remission surrogate: Computes the number of people recovering from depression based on the remission rate.
  • Calculate Coverage: Determines the actual coverage levels for each intervention, considering baseline, target, and scale-up parameters.
  • Calculate Disability Effects: Computes the impact of interventions on reducing the disability associated with depression.
  • Add remission impact to remission effect: Combines the inherent remission efficacy of interventions with other factors.
  • Modify remission effect by coverage: Adjusts the overall remission effect based on the proportion of the population reached by interventions.
  • Modify remission effect by PIN: Further refines the remission effect based on the proportion of the population in need of the intervention.
  • Add calculated remission impact to transform: Aggregates the remission effects of different interventions.
  • Modify remission surrogate by remission effect: Adjusts the number of people recovering based on the combined impact of interventions.
  • Add incidence impact to incidence effect: (For interventions affecting incidence) Combines inherent incidence reduction efficacy with other factors.
  • Modify incidence effect by coverage: Adjusts the overall incidence reduction effect by coverage.
  • Modify incidence effect by PIN: Further refines the incidence reduction effect.
  • Add calculated incidence impact to transform: Aggregates incidence reduction effects.
  • Modify incidence surrogate by incidence effect: Adjusts new case numbers based on combined incidence reduction impact.
  • Remove Disability Effects from 1.0: This step calculates a factor representing the remaining disability after accounting for intervention effects.
  • Calculate Healthy and Depression HYL: Calculates Health-Adjusted Life Years for healthy individuals and those with depression, considering their respective disability weights. (Note: "Asthma HYL" appeared in source, assumed to mean "Depression HYL").
  • Calculated Combined HYL: Aggregates HYL contributions, potentially modified by intervention effects on disability.
  • Calculate Combined DW: Calculates the overall disability weight experienced by those with depression, considering intervention effects.
  • Modify Combined DW with intervention effects: Adjusts the disability weight based on the effectiveness of interventions in reducing disability.
  • Calculated Modified HYL: Calculates the final Health-Adjusted Life Years for those with depression after accounting for intervention-modified disability.
  • Calculate DsFreeSus Disability Surrogate: Calculates HYL for the healthy, susceptible population.
  • Calculated Depression HYL Surrogate: Calculates HYL for the population with depression episodes, considering modified disability. (Note: "Asthma HYL Surrogate" appeared in source, assumed to mean "Depression HYL Surrogate").
  • Calculate Mortality Surrogate (Add CFR to Surrogate): Incorporates the base case fatality rate into the calculation of disease-specific deaths.
  • Record Births to Birth Node: The model calculates the number of births occurring in the population and stores this total.
  • Main Routine (Synchronous transfer): In this core step, the model applies rates and proportions to simulate people moving between groups (e.g., from healthy to having depression, from depression to recovered, or to a deceased state). This also includes background mortality and applying migration effects.
  • Push DepressionEpsd to Population Reached: Determines the number of individuals with depression who are eligible for and could potentially receive each intervention.
  • Modify Population Reached by PIN and Coverage: Calculates the actual number of people reached by each intervention by applying the population in need (PIN) proportions and the calculated coverage rates.
  • Record HYL: The model updates the total "Healthy Years Lived" by summing contributions from different population groups.
  • Add prevalence to YLD nodes: Calculates the number of people living with disability in each state for YLD calculations.
  • Multiply YLDs by Disability Weights: Applies the relevant disability weights (including those modified by interventions) to the populations in each state to quantify YLDs.
  • Migration of Populations: Adjusts population numbers in states to account for net migration.
  • Age the populations: This step simulates the entire population in each state getting older by one time unit (e.g., one year).
  • Women give birth: New births (calculated earlier) are added to the healthy population group, distributed by sex.
  • Add values to DALYs: This step aggregates YLDs and YLLs to calculate the total DALYs.
  • Calculate resource requirements and costs: Based on the number of people receiving interventions, this step calculates the demand for various resources (personnel time, medicines, visits) and their associated costs.
  • Record Metrics: This step records important results and numbers from the model for the current time period, such as population sizes in different states, DALYs, HYL, and resource utilization.

This sequence is repeated for each year of the simulation, allowing the model to project changes in population health and intervention impact over time.

4. Resource Requirement Assumptions

The model incorporates specific assumptions about the resources needed for each intervention. These are detailed below for each intervention type:

Intervention 1: Basic psychosocial treatment for mild depression

Target Population Node in Model: PopulationReached-AntiDepressantBasicPsychMild

Personnel Time Required per Case:

  • Enrolled Nurse (EN): Two 20-minute visits for psychosocial support.
  • Enrolled Nurse (EN): 5 minutes for basic screening during the first visit.
  • Professional Nurse (PN): 5 minutes for assessment during the first visit.

Visits or Inpatient Time Required per Case:

  • 2 outpatient visits.

Intervention 2: Basic psychosocial treatment and anti-depressant medication of first episode moderate-severe cases

Target Population Node in Model: PopulationReached-AntiDepressantBasicPsychModerate

Drugs and Supplies required Per Client:

  • Fluoxetine, 20 mg tab: 75% of cases receive 1 tablet per day for 180 days (total 180 units per case).
  • Citalopram, 20mg tab: 25% of cases receive 1 tablet per day for 180 days (total 180 units per case).

Personnel Time Required per Case:

  • Enrolled Nurse (EN): Two 20-minute sessions for basic psychosocial support.
  • Enrolled Nurse (EN): 5 minutes for basic screening during the first visit.
  • Professional Nurse (PN): 5 minutes for assessment during the first visit.
  • Doctor: One 10-minute visit for medication management.
  • Nurse (general): One 10-minute visit for medication monitoring.

Visits or Inpatient Time Required per Case:

  • 2 outpatient visits (for medication and support).
  • 2% of cases will require hospitalization for 14 inpatient days.

Intervention 3: Intensive psychosocial treatment and anti-depressant medication of first episode moderate-severe cases

Target Population Node in Model: PopulationReached-AntiDepressantIntensPsych

Drugs and Supplies required Per Client:

  • Fluoxetine, 20 mg tab: 75% of cases receive 1 tablet per day for 180 days (total 180 units per case).
  • Citalopram, 20mg tab: 25% of cases receive 1 tablet per day for 180 days (total 180 units per case).

Personnel Time Required per Case:

  • Nurse (general): One 10-minute visit (likely for medication monitoring/management).
  • Doctor: One 10-minute visit (likely for medication management/assessment).
  • Enrolled Nurse (EN): 5 minutes for screening.
  • Enrolled Nurse (EN) for therapy: 90% of cases receive 8 individual psychosocial therapy sessions, each lasting 50 minutes.
  • Enrolled Nurse (EN) for therapy: 10% of cases receive 2 individual psychosocial therapy sessions, each lasting 50 minutes.
  • Enrolled Nurse (EN) for therapy: 10% of cases (same 10% as above) receive 8 group psychosocial therapy sessions, each lasting 50 minutes (to a group of assumed participants).
  • Professional Nurse (PN): 5 minutes for assessment.

Visits or Inpatient Time Required per Case:

  • 2 outpatient visits for medication.
  • For therapy:
    • 90% of cases have 8 outpatient visits for individual therapy.
    • 10% of cases have 10 outpatient visits (2 individual + 8 group therapy visits).
  • 2% of cases will require hospitalization for 14 inpatient days.

Intervention 4: Intensive psychosocial treatment and anti-depressant medication of recurrent moderate-severe cases on an episodic basis

Target Population Node in Model: PopulationReached-AntiDepressantIntensPsychNEW

Drugs and Supplies required Per Client:

  • Fluoxetine, 20 mg tab: 75% of cases receive 1 tablet per day for 180 days (total 180 units per case).
  • Citalopram, 20mg tab: 25% of cases receive 1 tablet per day for 180 days (total 180 units per case).

Personnel Time Required per Case:

  • Same as Intervention 3 (Nurse, Doctor, EN screening, EN therapy sessions for 90%/10% individual/group, PN assessment).

Visits or Inpatient Time Required per Case:

  • Same as Intervention 3 (2 medication visits; 8 or 10 therapy visits; 2% hospitalization for 14 days).

Intervention 5: Intensive psychosocial treatment and anti-depressant medication of recurrent moderate-severe cases on a maintenance basis

Target Population Node in Model: PopulationReached-AntiDepressantIntensPsychREC

Drugs and Supplies required Per Client:

  • Fluoxetine, 20 mg tab: 75% of cases receive 1 tablet per day for 365 days (total 365 units per case).
  • Citalopram, 20mg tab: 25% of cases receive 1 tablet per day for 365 days (total 365 units per case).

Personnel Time Required per Case:

  • Nurse (general): Two 10-minute visits for medication.
  • Doctor: One 10-minute visit for medication.
  • Enrolled Nurse (EN): 5 minutes for screening.
  • Enrolled Nurse (EN) for therapy: 90% of cases receive 12 individual psychosocial therapy sessions, each lasting 50 minutes.
  • Enrolled Nurse (EN) for therapy: 10% of cases receive 2 individual psychosocial therapy sessions, each lasting 50 minutes.
  • Enrolled Nurse (EN) for therapy: 10% of cases (same 10% as above) receive 10 group psychosocial therapy sessions, each lasting 50 minutes.
  • Professional Nurse (PN): 5 minutes for assessment.

Visits or Inpatient Time Required per Case:

  • 3 outpatient visits for medication.
  • For therapy:
    • 90% of cases have 12 outpatient visits for individual therapy.
    • 10% of cases have 14 outpatient visits (2 individual + 10 group + 2 medication follow-ups for therapy, or 2 individual + 10 group, assuming medication visits are separate). Source says 10% get 14 visits for therapy.
  • (Inpatient days not specified for this intervention in source, unlike others).

5. Coverage Assumptions for Scenarios

The model can be run under different scenarios, each with specific assumptions about intervention coverage levels and how they change over the simulation period (2025-2050). Scale-up is generally from 2025 (Year 0) to 2030 (Year 5).

Scenario: Default Scenario

Description: Where default coverage rates stay the same. All relevant parameters are exposed for editing.

  • Intervention: Basic psychosocial treatment for mild depression (Intervention 1)
    • Baseline Coverage: 5.0%
    • Target Coverage: 5.0%
    • Scale-up Period: from 2025 to 2030 (coverage remains constant at baseline)
  • Intervention: Basic psychosocial treatment and anti-depressant medication of first episode moderate-severe cases (Intervention 2)
    • Baseline Coverage: 5.0%
    • Target Coverage: 5.0%
    • Scale-up Period: from 2025 to 2030 (coverage remains constant at baseline)
  • Intervention: Intensive psychosocial treatment and anti-depressant medication of first episode moderate-severe cases (Intervention 3)
    • Baseline Coverage: 5.0%
    • Target Coverage: 5.0%
    • Scale-up Period: from 2025 to 2030 (coverage remains constant at baseline)
  • Intervention: Intensive psychosocial treatment and anti-depressant medication of recurrent moderate-severe cases on an episodic basis (Intervention 4)
    • Baseline Coverage: 5.0%
    • Target Coverage: 5.0%
    • Scale-up Period: from 2025 to 2030 (coverage remains constant at baseline)
  • Intervention: Intensive psychosocial treatment and anti-depressant medication of recurrent moderate-severe cases on a maintenance basis (Intervention 5)
    • Baseline Coverage: 5.0%
    • Target Coverage: 5.0%
    • Scale-up Period: from 2025 to 2030 (coverage remains constant at baseline)

Scenario: All-On Scenario

Description: Where all interventions are scaled up to their target coverage.

  • Intervention: Basic psychosocial treatment for mild depression (Intervention 1)
    • Baseline Coverage: 5.0%
    • Target Coverage: 20.0%
    • Scale-up Period: from 2025 to 2030
  • Intervention: Basic psychosocial treatment and anti-depressant medication of first episode moderate-severe cases (Intervention 2)
    • Baseline Coverage: 5.0%
    • Target Coverage: 20.0%
    • Scale-up Period: from 2025 to 2030
  • Intervention: Intensive psychosocial treatment and anti-depressant medication of first episode moderate-severe cases (Intervention 3)
    • Baseline Coverage: 5.0%
    • Target Coverage: 20.0%
    • Scale-up Period: from 2025 to 2030
  • Intervention: Intensive psychosocial treatment and anti-depressant medication of recurrent moderate-severe cases on an episodic basis (Intervention 4)
    • Baseline Coverage: 5.0%
    • Target Coverage: 20.0%
    • Scale-up Period: from 2025 to 2030
  • Intervention: Intensive psychosocial treatment and anti-depressant medication of recurrent moderate-severe cases on a maintenance basis (Intervention 5)
    • Baseline Coverage: 5.0%
    • Target Coverage: 20.0%
    • Scale-up Period: from 2025 to 2030

Scenario: Basic psychosocial support for mild cases

Description: Scaling up the intervention to target coverage.

  • Intervention: Basic psychosocial treatment for mild depression (Intervention 1)
    • Baseline Coverage: 5.0%
    • Target Coverage: 20.0%
    • Scale-up Period: from 2025 to 2030 (Other interventions remain at their default/baseline levels of 5.0% as per the "Default Scenario").

Scenario: Basic psychosocial support and anti-depressant medication of first episode moderate-severe cases

Description: Scaling up the intervention to target coverage.

  • Intervention: Basic psychosocial treatment and anti-depressant medication of first episode moderate-severe cases (Intervention 2)
    • Baseline Coverage: 5.0%
    • Target Coverage: 20.0%
    • Scale-up Period: from 2025 to 2030 (Other interventions remain at their default/baseline levels of 5.0% as per the "Default Scenario").

Scenario: Psychological treatment and anti-depressant medication of first episode moderate-severe cases

Description: Scaling up the intervention to target coverage.

  • Intervention: Intensive psychosocial treatment and anti-depressant medication of first episode moderate-severe cases (Intervention 3)
    • Baseline Coverage: 5.0%
    • Target Coverage: 22.0%
    • Scale-up Period: from 2025 to 2030 (Other interventions remain at their default/baseline levels of 5.0% as per the "Default Scenario").

Scenario: Basic psychosocial support and anti-depressant medication of recurrent moderate-severe cases on an episodic basis

Description: Scaling up the intervention to target coverage.

  • Intervention: Intensive psychosocial treatment and anti-depressant medication of recurrent moderate-severe cases on an episodic basis (Intervention 4)
    • Baseline Coverage: 5.0%
    • Target Coverage: 20.0%
    • Scale-up Period: from 2025 to 2030 (Other interventions remain at their default/baseline levels of 5.0% as per the "Default Scenario"). (Note: Scenario name uses "Basic psychosocial support..." but applies to Intervention 4, which is "Intensive...").

Scenario: Psychological treatment and anti-depressant medication of recurrent moderate-severe cases on an episodic basis

Description: Scaling up the intervention to target coverage.

  • Intervention: Intensive psychosocial treatment and anti-depressant medication of recurrent moderate-severe cases on a maintenance basis (Intervention 5)
    • Baseline Coverage: 5.0%
    • Target Coverage: 20.0%
    • Scale-up Period: from 2025 to 2030 (Other interventions remain at their default/baseline levels of 5.0% as per the "Default Scenario"). (Note: Scenario name uses "...on an episodic basis" but applies to Intervention 5, which is "...on a maintenance basis" and has an incidence reduction effect).

Issues for Authors

  1. Subroutine Labeling ("Asthma HYL"): In Section 3 (Subroutines), the terms "Calculate Healthy and Asthma HYL" and "Calculated Asthma HYL Surrogate" appear in the source document. It is assumed these are placeholders or internal labels and should refer to "Depression HYL." This has been noted in the reformatted text.
  2. Scenario Naming vs. Intervention Details:
    • The scenario "Basic psychosocial support and anti-depressant medication of recurrent moderate-severe cases on an episodic basis" (Section 5) scales up Intervention 4, which is formally named "Intensive psychosocial treatment and anti-depressant medication of recurrent moderate-severe cases on an episodic basis." The scenario name uses "Basic" while the intervention is "Intensive."
    • The scenario "Psychological treatment and anti-depressant medication of recurrent moderate-severe cases on an episodic basis" (Section 5) scales up Intervention 5, which is formally named "Intensive psychosocial treatment and anti-depressant medication of recurrent moderate-severe cases on a maintenance basis." The scenario name uses "episodic basis" while the intervention is for "maintenance basis" and uniquely includes an incidence reduction effect. These discrepancies have been noted in the reformatted text.
  3. Therapy Session Logic in Intervention 3 & 4: For Interventions 3 and 4, the personnel time for EN therapy states: "90% of cases receive 8 individual psychosocial therapy sessions... 10% of cases receive 2 individual psychosocial therapy sessions... 10% of cases (the same 10% receiving fewer individual sessions) receive 8 group psychosocial therapy sessions..." The visit count aligns with this (90% get 8 visits, 10% get 10 visits). This implies the 10% group gets both 2 individual and 8 group sessions. Clarity on group size for resource calculation might be useful if not defined elsewhere.
  4. Therapy Visit Calculation for Intervention 5: For Intervention 5, the personnel time for EN therapy is: "90% receive 12 individual... 10% receive 2 individual... 10% (same 10%) receive 10 group..." The visits section states: "For therapy: 90% get 12 outpatient visits; 10% get 14 outpatient visits." This implies the 10% group receives 2 individual + 10 group sessions (12 visits) plus 2 additional visits. The purpose of these 2 extra visits for the 10% (beyond the individual and group therapy sessions) should be clarified if they are not medication visits (which are listed separately as 3 visits for 100% of cases).
  5. Inpatient Days for Intervention 5: Intervention 5 ("...maintenance basis") does not specify inpatient day requirements, unlike Interventions 2, 3, and 4 which all state "2% of cases will require hospitalization for 14 inpatient days." This might be intentional (maintenance less likely for acute hospitalization) or an omission.
  6. Simulation Period: The run period of 2025-2050 was assumed for consistency with the Anxiety model, as the Depression overview did not explicitly state it. Scenario scale-up periods (Year 0 to Year 5) were interpreted based on a 2025 start. This should be confirmed.
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