To understand how genetic, environmental, and life-course factors interact to shape brain, behavioural, and psychological development, the Indian Council of Medical Research (ICMR) launched a major longitudinal cohort study titled the Pathways to Resilience And Mental health (PARAM) project.
Introduction
Due to socio-cultural and environmental diversity, rapid urbanization and digitalization, India has a potential for neurodevelopmental studies. Some previous cohort studies have shown that factors such as “socioeconomic status, childhood adversity, maternal mental health, caregiving practices, and environmental toxins all influence cognitive and emotional development” (Holla et al., 2025). However, many cohort studies target late childhood, are not large, and provide only limited combined exposure-outcome information.
As reported by Holla et al. (2025), ICMR in coordination with the National Institute of Mental Health and Neurosciences (NIMHANS) from Bengaluru, launched a large PARAM project, focusing on individuals from the prenatal period into early adulthood across diverse social and ecological settings.
By tracking neurodevelopmental trajectories, linking them to life exposures, and identifying risk and resilience factors, PARAM aims to reveal what shapes mental well-being early in life.
Because of the longitudinal design and national scale, the results of PARAM study will emerge over time. However, the project’s goals, study design, methods, and planned analyses are detailed in the study protocol published in BMC Psychiatry Journal by Holla et al. (2025).
We follow up on the project’s outcomes and findings, as our Photon Cap technology is used as one of the methods to measure cerebral hemodynamic signals from the prefrontal cortex during resting-state sessions as part of the research process.
Objectives
According to Holla et al. (2025), PARAM is primarily designed to track how development unfolds over time, and identify when and why certain pathways diverge, particularly in ways linked to mental health outcomes.
To manage and combine data from multiple sites while accounting for site differences in the analyses, the study protocol sets out the following goals:
- tracing the development of the brain, cognition, behaviour, and mental health from before birth through early adulthood;
- examining how maternal stress, nutrition, inflammation, toxins, digital media engagement, and socio-environmental adversity influence development, with focus on critical and sensitive periods;
- applying gene-to-environment (G×E) approach and normative models to integrate genetic and environmental data and generate individual-level scores for personalized insights;
- studying the biological, brain imaging, cognitive, and social factors that increase risk or provide protection in the development and progression of psychiatric symptoms;
- developing an open platform for multimodal data to enable reproducible research and global data sharing;
Timeframe
The PARAM study began in May 2023 with a nine-month preparation phase focused on hiring staff, adapting assessment tools into seven Indian languages, setting up digital systems, and training teams across study sites.
Participant recruitment began in February 2024 and will continue until April 2026, being carried out in phases across study sites.
Baseline assessments are planned to run over 18 months at each site and be completed within three months of a participant’s enrollment, with all assessments scheduled to finish by July 2026.
Participants
PARAM project aims to enroll around 9000 participants, from the prenatal period (before birth up to age 6) through young adulthood (23-30 years), to track early-life exposures (Holla et al., 2025).
Participants are divided into two cohorts:
- pregnant mothers and infants followed from enrolment or birth to age two, with six-monthly assessments to capture changes during the first 1000 days of life;
- ages of 2-30 years with overlapping age groups to enable reconstruction of age-related development within a shorter timeframe.
The study was approved by the Institutional Ethics Committees at all participating sites, and obtained informed consent with written consent from a parent or legal guardian on minors behalf (Holla et al., 2025).
Recruitment takes place in both urban and rural areas, including clinics, community groups, schools, and high-risk settings, to study developmental differences and mental health outcomes.
Methods and Procedures
Participants undergo a combination of assessments including questionnaires (interviewer- and self-administered), performance-based neurocognitive tasks, neurophysiological tests, and neuroimaging protocols.
Assessments are organized into core measures for all participants and deep measures (with fNIRS and MRI) for a subset. Standardized procedures, quality control, and centralized training ensure consistency across sites and visits (Holla et al., 2025).
During the core assessment all participants complete one or two assessment visits lasting about 4-5 hours with breaks. Follow-up visits occur within one month before to three months after the planned date. Any unfinished assessments are completed within three months of recruitment.
The assessment begins with documentation of prenatal growth from ultrasound records and continues with longitudinal developmental assessments spanning infancy to adulthood, including cognitive, social, pubertal, and caregiver-child interaction measures (Holla et al., 2025).
Participants and parents complete age-appropriate questionnaires covering temperament, personality, psychopathology, family history, caregiving context, adversity, and environmental exposures, alongside standardized neuropsychological tasks assessing attention, memory, executive function, and social cognition (Holla et al., 2025).
Anthropometry, nutritional biomarkers, and multi-matrix biospecimens (e.g., blood, saliva, hair, urine) are collected to support genetic, metabolic, inflammatory, hormonal, and environmental exposure analyses (Holla et al., 2025).
Neurophysiological measures include postural balance testing and heart rate variability during rest and isometric stress challenge.
As part of a deep assessment subset, the participants additionally undergo MRI and resting-state fNIRS acquisition, with centralized data management and cross-site quality control procedures.
Data Analysis Approach
Holla et al. (2025) report emphasizes that PARAM handles missing data using likelihood-based methods, multiple imputation, and inverse probability weighting, while accounting for non-random missingness and differences in mode, language, and site.
To detect meaningful patterns, PARAM uses a strategic sampling approach. It intentionally includes more individuals at developmental extremes and across important exposures – such as levels of urbanisation, pollution, and adversity. This boosts the study’s ability to model complex, nonlinear developmental trajectories and interactions.
Developmental trajectories across neurocognition, symptoms, imaging, and anthropometry are modelled using generalized additive mixed models (GAMM), generalized additive models for location, scale, and shape (GAMLSS), and latent growth or mixture models (Holla et al., 2025).
Emphasizing on generalized transdiagnostic mechanisms instead of discrete diagnostic categories, PARAM enables individual-level inference.
fNIRS Application
Photon Cap C20 is used to collect resting-state fNIRS data. Activity from the prefrontal cortex is recorded for up to 15 minutes at baseline and follow-up visits, with at least 10 minutes of usable, high-quality data retained after processing.
The Photon Cap system uses 16 LED sources and 10 detectors arranged over the bilateral prefrontal cortex. It incorporates both long- and short-separation channels to distinguish cortical signals from physiological artifacts.
The recorded data are processed with a standardized channel-level quality checks, calibration and physiological artifacts removal, as well as estimation of functional connectivity measures. The sessions are repeated if signal quality is insufficient to ensure reliable, consistent measurements throughout the study.
Such implementation of the Photon Cap allows PARAM to integrate non-invasive brain activity measurements alongside MRI to help chart neurodevelopmental and functional developmental trajectories from early life into adulthood.
Potential Implications
Holla et al. (2025) aim to provide important insights into how nutrition, caregiving, education, and environmental conditions influence development from childhood through adolescence. The focus on prenatal and early childhood stages helps identify sensitive periods for prevention, while follow-up into adolescence and young adulthood clarifies risks during key life transitions.
Potential outputs include developmental reference charts, exposure-trajectory maps, and risk stratification tools to support maternal-child health programs, environmental policies, and digital wellbeing initiatives (Holla et al., 2025).
An open, governed-access database and biobank will also support further research and international collaboration.
Based on original publication: Holla, B., Sharma, E., Venkataramanan, S. et al. The PAthways to Resilience And Mental health (PARAM) project: protocol for a multi-site developmental cohort in India. BMC Psychiatry 25, 1051 (2025). https://doi.org/10.1186/s12888-025-07492-x