Why Intrinsic Capacity Needs More Than Depression Scores to Measure Psychological Health

Intrinsic capacity, introduced by the WHO in 2015, describes the individual-level attributes that underpin functional ability in later life. It is now used as an entry point for clinical care, an outcome in intervention trials, and a training target for epigenetic clocks. Publications are rising quickly, and the US ARPA-H program is funding work to validate intrinsic capacity measures as clinical trial outcomes. The editorial argues that this momentum has outpaced basic work on how the construct should be conceptualized and measured.

The construct is generally viewed as having five subdomains: cognitive, locomotor, sensory, psychological and vitality. Psychological capacity is the least settled. Early work framed it around mood and emotional vitality, and in practice most studies substitute depression measures because they are readily available. The authors note that mood disorders capture only a sliver of the psychological attributes that shape functioning.

The editorial is a commentary on a consensus process by Hagani et al. (MOSAIC International Working Group) in the same issue, not a new empirical study. That group proposed a working definition of psychological capacity as the intrinsic psychological characteristics, assets and skills that enable a person to respond to internal stressors and contextual demands. These are expressed through cognitive appraisal, affect and emotional regulation, adaptability, coping, social competence and personal agency. The editorial supports the group's decision to focus on what is inside the person rather than social networks, capital or norms. It therefore favors "psychological" over "psychosocial" capacity. It also highlights the difficulty of overlap between subdomains, such as cognitive and psychological, sensory and cognitive, or locomotor and cognitive. Some attributes, such as sleep, may fit no subdomain neatly.

The authors suggest that a broader construct could reveal more nuanced trajectories across the life course. Depression-based measures show the least age-related change of any subdomain. Many psychological attributes can improve with age, and psychological capital has been developed in workplace settings. Psychological capacity might therefore be strengthened through interventions at key life stages. The authors also argue that future measurement models should account for correlations among variables rather than simply adding them.

The next step is a realistic measurement framework for both population research and individual care planning. It should be psychometrically sound, available in brief and comprehensive forms, and sensitive to change. The authors acknowledge that perfection is unattainable and that any measure can only be a marker of a complex, personal construct. Researchers still depend on legacy datasets poorly suited to a strengths-based framing. At a minimum, the field should move beyond depressive symptoms as a proxy for the whole.