By Fabiola Balmori and Karina Benitez Lin A follow-up to our March 2026 post on building Lunava

TL;DR

In our first post, we described Lunava as a scalable CBT-based intervention for depression and anxiety during the menopause transition. Since then, our understanding of the problem has deepened in two important ways. First, we've expanded the frame: the relevant population is not just women in perimenopause but women across the full climacteric (menopause transition)  — a 15-to-25-year arc that includes perimenopause, menopause, and postmenopause — and the psychological burden doesn't resolve at the end of it. Second, and more importantly for the EA case: we've built a detailed argument, supported by official Mexican data and high-quality clinical evidence, that each woman we reach may represent 5 to 6 people who benefit. This post explains why, what the evidence is, and what it means for how we think about cost-effectiveness.

What changed in our framing

Our first post focused on perimenopause and menopause. That framing was accurate but incomplete.

The climacteric is not an event — it's a transition that begins around age 40 and extends well past the last menstrual period. The Study of Women's Health Across the Nation (SWAN), which followed women for over ten years, found that postmenopause remains a period of elevated depression risk, especially for women who entered it without psychological support. Patterns of depressive symptoms before the final menstrual period are highly predictive of what happens after it. Without intervention, symptoms don't resolve on their own.

The Lancet 2024 Series on Menopause put it directly: there is a two-to-fourfold increased risk of depressive symptoms across and beyond the menopause transition, and mental health should be a core component of climacteric care — not an optional add-on. In Latin America, that core component is virtually absent.

This means our 8-session program is relevant not only to women in perimenopause, but to women in postmenopause who went through the transition without support and are carrying an accumulated psychological burden. According to INEGI's 2020 Census and CEPAL's 2024 Demographic Observatory, approximately 16–17 million women in Mexico and an estimated 70–80 million women across Latin America and the Caribbean are currently between ages 40 and 65, somewhere along this climacteric arc. These are not women approaching a transition. Most of them are already living it, and the vast majority without access to any structured psychological support.

The scale, updated

When we wrote our first post, we cited 18 million women between 40 and 59 in Mexico. That figure holds,  but it understates the real scope. Accounting for the full climacteric arc (perimenopause through postmenopause, ages 40–65+), Mexico alone has an estimated 16–18 million women currently living somewhere along this transition, based on INEGI's 2020 Census age-distribution data. Across Latin America and the Caribbean, that number rises to an estimated 35–50 million women in the 40–65 age range, a working estimate derived from CEPAL's 2024 Demographic Observatory regional population data, since no single published figure captures this exact cohort. Globally, 1.2 billion women will be in some phase of the climacteric by 2030, and 76% of them will live in low- and middle-income countries where healthcare systems have limited mental health infrastructure and virtually no culturally adapted programming for this stage of life.

The economic cost of this gap is not invisible. The Health and Economic Impacts of Menopause estimates a $150 billion annual global productivity loss attributable to unaddressed climacteric symptoms. In the UK alone, the NHS Confederation (2024) estimates that menopause-related unemployment costs £1.5 billion per year. There are no equivalent estimates for Latin America, partly because the problem is structurally invisible in the data, which is itself part of the case for neglectedness.

The argument we hadn't made explicitly: the cascade effect

Here is the most important thing we've learned since our first post.

In our initial framing, we thought about impact as: one woman in perimenopause, treated with CBT, experiences fewer symptoms and better quality of life. That's a real impact. But it significantly undercounts what actually happens.

Women in the climacteric in Mexico are, in the vast majority of cases, the central caregiving node of multiple simultaneous systems of dependence. They are caring for children still in active parenting (the millennial generation that delayed motherhood to ages 27–30 now has teenage children while entering perimenopause), for elderly parents who have no access to institutional care, and in many cases for grandchildren. According to the Encuesta Nacional para el Sistema de Cuidados (ENASIC 2022, INEGI), 75.1% of Mexico's 31.7 million informal caregivers are women, and half of them are between 30 and 59 years old — that  encompasses climacteric range. Only 22.4% of elderly adults in Mexico receive adequate institutional care; the remaining 77.6% depend on informal caregivers, overwhelmingly their daughters in midlife.

The Encuesta Nacional sobre Uso del Tiempo (ENUT 2024, INEGI) measured this more precisely: women in Mexico dedicate 39.7 hours per week to unpaid domestic and care work, compared to 18.2 hours for men — a gap of 21.5 hours per week. The unpaid care economy in Mexico is estimated at 26.3% of GDP (INEGI, 2023).

What this means in practice: a woman in climacteric in Mexico is typically the psychological and logistical anchor for 1–2 children, a partner, 1–2 elderly parents who lack institutional support, and often grandchildren — plus her presence in a work environment that is affected by her emotional and cognitive functioning. Conservatively: 5 to 6 people whose wellbeing is directly shaped by hers.

The clinical evidence for why this matters

This isn't a speculative argument. The clinical evidence for psychological spillover effects is at the top of the evidence hierarchy.

The most cited study is the STAR*D Child Study (Weissman, Pilowsky et al., JAMA, 2006), an ancillary investigation of the large STAR*D clinical trial treating maternal depression. The finding is striking: 100% of children whose mothers achieved full remission remained free of psychiatric diagnoses at 3 months, while 17% of children whose mothers did not remit acquired a new diagnosis during that period. A one-year follow-up confirmed the pattern: externalizing behavioral problems decreased only in children of mothers who remitted, and increased in children of mothers who remained depressed.

A more recent meta-analysis of 47 randomized controlled trials (7,745 participants, Journal of the American Academy of Child & Adolescent Psychiatry, 2026) confirmed the mechanism: psychological interventions targeting the mother produced a moderate effect on maternal depression (SMD=0.57, 95% CI: 0.43–0.70) and documented positive effects on child functioning and parenting quality. Treating the mother is an intervention in the household.

A 2025 umbrella review of meta-analyses on informal caregivers found prevalence rates of 33.35% for depression, 35.25% for anxiety, and 49.26% for burnout in this population. The burden is not contained in the woman receiving care — it radiates through every relationship she holds.

What this means for cost-effectiveness: the StrongMinds analogy

In the EA community, StrongMinds is probably the clearest precedent for this type of argument. The Happier Lives Institute evaluated StrongMinds in 2021 and estimated it was 9 to 12 times more cost-effective than GiveDirectly — the AE benchmark for unconditional cash transfers — partly because it incorporated spillover effects on children and households as impact multipliers. StrongMinds estimates that for every woman treated, the positive impact reaches 4 to 5 people in her immediate environment.

The methodological logic is not new to the EA literature. GiveDirectly's Kenya RCT (Haushofer & Shapiro, 2013) was evaluated with household-level spillovers incorporated into GiveWell's cost-effectiveness estimates. Deworm the World became one of EA's most-recommended interventions partly on the strength of network effects — children who weren't treated directly still benefited from reduced transmission. Counting indirect beneficiaries in a network is accepted methodology, not optimistic speculation.

Lunava's case for a similar multiplier is, if anything, better evidenced than StrongMinds', because the Mexican data allows us to document the structure of the caregiving network directly rather than by analogy. The ENASIC and ENUT surveys quantify precisely who these women are caring for, how many hours they spend doing it, and what portion of their wellbeing deterioration is attributable to unsupported caregiving burden. The STAR*D Child Study and the 2026 meta-analysis establish the mechanism through which that burden transmits to children. The causal chain is documented at every link.

Our conservative estimate: 1 woman treated by Lunava → 5–6 people benefited. With groups of 8–12 women per cohort, each intervention cycle reaches 40–72 people at direct and indirect impact combined.

What we're building and what comes next

We are currently running pilots in Mexico with a focus on:

• Measuring early changes in PHQ-9 and GAD-7 scores across the 8-session program
• Testing retention and adherence in online group formats
• Exploring adaptation of the content for postmenopause populations, not only perimenopause
• Beginning to develop a methodology for tracking second-order outcomes — relationship quality, caregiver burden reported by participants, and basic measures of family functioning

We remain in the prototyping and iteration phase. We are not yet at impact measurement. But we are deliberately building toward an infrastructure that can eventually generate the evidence needed to make the cascade argument rigorously, not just inferentially.

In the longer term, we see a pathway from Mexico to Spanish-speaking Latin America: the cultural adaptations are modest across contexts, the digital format eliminates geographic barriers, and the marginal cost per additional participant in a group online format is very low.

Questions we are still working through

On the cascade argument: How much of the 5–6 multiplier can we credibly claim in a cost-effectiveness model without direct measurement of second-order outcomes? We are aware this is the methodologically weakest part of our current framing, even if the directional evidence is strong. We are actively thinking about how to design pilots that can generate at least proxy indicators of family-level change.

On postmenopause adaptation: Our current CBT modules were designed primarily with perimenopause in mind. The psychoeducational content and pacing may need meaningful revision for women in established postmenopause. We don't yet know how much.

On retention across the full 8 sessions: Our early signals are encouraging, but maintaining engagement across the full program — especially for women juggling the care burden we describe — remains a real design challenge.

On measurement: We are currently using PHQ-9 and GAD-7 as primary outcomes. We are considering whether to add a caregiver burden scale (like the Zarit or a validated adaptation) as a secondary outcome to begin capturing the dual role many participants hold.

Invitation for feedback

We are sharing this updated framing because the cascade argument is, in our view, the most important thing we've developed since our first post — and we want to pressure-test it before we build it more formally into our cost-effectiveness model.

Specifically, we would welcome input on:

• Methodological precedents for counting spillover effects in mental health interventions in LMIC contexts
• Measurement approaches for family-level or network-level outcomes in group CBT programs
• Skeptical takes on the 5–6 multiplier: where does the argument break down?
• Funders or researchers working at the intersection of women's health, caregiver mental health, and family systems in Latin America

We would also welcome connections to anyone working on the economics of care in Latin America, or on postmenopause mental health specifically.

You can reach us directly at karina@lunava.ngo or fabiola@lunava.ngo, visit our website at lunava.ngo, or engage in the comments below.

We are building this carefully and openly, and we are genuinely grateful for the community's engagement.

Sources referenced in this post are drawn from: INEGI ENASIC 2022, INEGI ENUT 2024, INEGI Cuenta Satélite del Trabajo No Remunerado 2023, PAHO/WHO 2023, SWAN Study (Bromberger et al., PMC3197240), The Lancet Series on Menopause 2024, Pilowsky et al. JAMA 2006, meta-analysis of 47 RCTs (JAACAP 2026), Happier Lives Institute 2021, Haushofer & Shapiro 2013.