Public health

Study and action concerning health at the population level. Prevention research evaluates benefits, harms, reach and distribution of outcomes as well as efficacy among those who receive an intervention.

Intervention intended to reduce new cases or relevant risks before the target disorder develops. A change in knowledge or symptoms is not automatically evidence of fewer first onsets; research must specify baseline diagnostic status and follow-up outcomes.

Prevention targeting people showing early signs or markers without currently meeting the relevant diagnostic threshold. A study enrolling both previously affected and never-affected participants should distinguish recurrence from first onset.

Prevention targeting a group with elevated risk because of shared characteristics or experiences, without requiring each recipient to show early symptoms. Parental bereavement is one example of a selection criterion, not itself a diagnosis.

A preventive program involving caregiver and youth groups after parental death, targeting parenting, coping and adjustment. Trials distinguish changes in symptoms and functioning from uniform prevention of every diagnosis.

Prevention offered to a whole specified population regardless of individually assessed risk. Universal delivery can produce different effects across subgroups and does not imply that every participant has equal risk.

A cognitive-behavioral prevention program studied in school and other settings. A trial with a nonspecific-program comparison found heterogeneous school results and no overall average depressive-symptom benefit in the full sample; program identity alone does not guarantee prevention of disorder.^[ref]

A classroom behavior-management approach using rules, teams and contingent rewards. Preventive field trials test whether changing early classroom behavior affects later outcomes; results depend on population, implementation and follow-up, not only on the program's name.

Study of the distribution and determinants of health-related outcomes in populations. Incidence, recurrence and prevalence answer different questions and should not be exchanged when evaluating prevention.

An epidemic extending over a large geographic area or across countries. The term describes distribution and does not by itself specify the risk or severity for one individual.

Study of the distribution, determinants and course of psychiatric outcomes in populations. Differences in symptom burden, first-onset incidence, recurrence and service-record diagnoses require different interpretations.

A psychiatric epidemiologist who used an externally generated income change to investigate childhood psychiatric outcomes.^[ref]

A characteristic associated with lower risk or a weaker effect of a risk exposure under specified conditions. Causal protection requires stronger evidence than an unadjusted association.

A pattern in which a resource modifies the relationship between adversity and an adverse outcome. In the model $\mathbb{E}[D\mid S,P]={\beta }_0+{\beta }_{1}S+{\beta }_{2}P+{\beta }_{3}SP$, a negative ${\beta }_3$ attenuates the adversity slope as the resource increases. Its interpretation is scale dependent, and an observational interaction is not automatically a causal buffering effect.

A characteristic associated with increased probability of an outcome. Association can arise from causal influence, confounding or selection; being predictive does not automatically make a factor a modifiable causal target.

The difference between two outcome probabilities over specified populations and follow-up periods. With intervention risk $p_1$ and comparison risk $p_0$, a beneficial reduction in an adverse outcome has $RD<0$ and absolute risk reduction $p_0-p_1$. A causal interpretation requires a suitable design or identification assumptions; a simple difference between selected observational groups is not automatically a treatment effect.