Measured outcomes
Follow a research question across substances. Study populations, exposure, instruments, and limitations stay attached to each finding.
Attention
Performance on tasks that test selecting or switching attention. A task result does not measure general intelligence or subjective focus.
Depression symptom severity
Severity measured with a specified clinical instrument, population and follow-up interval; a scale change does not by itself establish remission.
Episodic memory
Memory for associations and events, operationalized here through a specified cognitive test rather than a general memory score.
Exercise performance
Performance outcomes during exercise or training.
Measured wakefulness
Sleep latency or wake-maintenance measurements under defined laboratory conditions; not interchangeable with subjective alertness.
Muscle creatine stores
The measured concentration of total creatine in skeletal muscle. Tissue concentration is a biochemical outcome, not a subjective benefit score.
Sleep
Measured sleep outcomes, such as onset time and continuity. Direction and clinical meaning depend on the endpoint and population.
Stroke recovery
Functional and neurological recovery after stroke, measured using specified clinical scales and follow-up.
Definitions are original editorial summaries with linked sources. A connection describes its recorded context; it does not establish a universal effect or clinical benefit. Read our methods.