Mental health can be measured through standardized questionnaires, physiological markers, cognitive tests, and functional assessments. No single tool captures the full picture, but combining a few approaches gives you a reliable read on where you stand. Some methods take less than five minutes and can be done at home, while others require a clinician or specialized equipment.
Screening Questionnaires You Can Take Yourself
The most widely used self-report tool for depression is the PHQ-9, a nine-item questionnaire that asks how often you’ve experienced specific symptoms over the past two weeks. Each item is scored 0 to 3, giving a total between 0 and 27. Scores of 0 to 4 indicate minimal or no depression, 5 to 9 mild, 10 to 14 moderate, 15 to 19 moderately severe, and 20 to 27 severe. A score of 10 or above is the most common threshold clinicians use to flag the need for further evaluation.
For anxiety, the GAD-7 follows a similar format with seven items and uses the same 0-to-3 scoring per question. Both tools are free, publicly available, and take about two to three minutes to complete. They’re not diagnostic on their own, but they give you a concrete number to track over time, which is one of the most practical things you can do if you’re trying to understand whether your mental health is improving or declining.
A broader option is the WHO’s Quality of Life questionnaire (WHOQOL-BREF), which measures 26 items across four domains: physical health, psychological well-being, social relationships, and environment. Scores are converted to a 0-to-100 scale for each domain, so you can see where you’re thriving and where you’re struggling. This tool is especially useful if your concern isn’t a specific disorder but a general sense that something feels off. It captures satisfaction with sleep, energy, self-esteem, personal relationships, access to healthcare, and safety, giving a more complete snapshot than a depression or anxiety screen alone.
Measuring How Well You Function Day to Day
Symptom severity is only half the story. Two people with identical PHQ-9 scores can have very different lives depending on how much those symptoms interfere with work, relationships, and basic self-care. The WHO Disability Assessment Schedule (WHODAS 2.0) was designed to capture exactly this. It measures functioning across six domains: cognition (understanding and communicating), mobility, self-care (hygiene, dressing, eating), getting along with others, life activities (domestic tasks, work, school), and participation in community life.
This kind of functional assessment matters because improvement in mental health doesn’t always show up as fewer symptoms first. Sometimes you start handling daily responsibilities better, reconnecting socially, or sleeping more consistently before your mood scores budge. Tracking functioning alongside symptoms gives you a more honest view of progress.
Screening Tools for Children and Teens
Most adult questionnaires don’t translate well to younger age groups. The Strengths and Difficulties Questionnaire (SDQ) was built specifically for children aged 2 to 17. It contains 25 items split across five subscales: emotional symptoms, conduct problems, hyperactivity and inattention, peer relationship problems, and prosocial behavior. Parents or teachers fill out the version for kids aged 4 to 17, with a slightly modified version available for 2-to-4-year-olds. Children aged roughly 11 to 17 can complete a self-report version, depending on their reading level.
What sets the SDQ apart is that it doesn’t just flag problems. The prosocial behavior subscale measures positive traits like helpfulness, kindness, and sharing. This makes it less stigmatizing for families and gives a more balanced view of a child’s emotional development.
Physiological Markers That Reflect Mental State
Your body carries measurable signals of mental distress, even when you can’t articulate what you’re feeling. Two of the most studied are cortisol levels and heart rate variability (HRV).
Cortisol is a stress hormone. People with depression tend to have higher baseline cortisol levels, reflecting an overactive stress response system that doesn’t properly dial itself back down. HRV, the variation in time between consecutive heartbeats, tends to be lower in people with depression. Higher HRV generally signals a nervous system that can flexibly respond to changing demands, while lower HRV suggests the system is stuck in a more rigid, stressed state. Research has shown that even a single dose of cortisol administered in a lab setting reduces HRV across multiple measures, regardless of whether participants had a history of depression.
You can track HRV at home with many modern smartwatches and chest-strap heart rate monitors. While consumer devices aren’t as precise as clinical-grade equipment, they can reveal trends. A sustained drop in your HRV over weeks, combined with worsening sleep or mood, is a meaningful signal worth paying attention to.
Cognitive Tests That Reveal Subtle Changes
Depression, anxiety, and chronic stress don’t just change how you feel. They change how you think. Cognitive flexibility, the ability to shift attention between tasks and adjust to new rules, is one of the first capacities to decline under mental health strain.
The Trail Making Test is one of the oldest and most validated ways to measure this. Part A asks you to connect numbered circles in order (1, 2, 3…) as fast as possible. Part B raises the difficulty: you alternate between numbers and letters (1, A, 2, B, 3, C…), which forces your brain to suppress the automatic urge to keep following one sequence. The time it takes to complete Part B reflects cognitive flexibility and working memory. A completion time over 100 seconds has been correlated with meaningful impairment in real-world tasks like driving. The difference between your Part A and Part B times is considered the purest indicator of your switching ability.
If you notice that tasks requiring mental juggling, like following a conversation while cooking, managing multiple deadlines, or adjusting plans on the fly, have become noticeably harder, that cognitive dimension of mental health may be worth exploring with a professional.
Digital Tools and Passive Tracking
A growing area of mental health measurement uses data your phone already collects. Researchers call this digital phenotyping: using passive smartphone data to detect shifts in behavior that correlate with mental health changes. Studies have tracked call log patterns (frequency, duration, and timing of calls), screen unlock behavior (how often and how long), and even battery charging patterns as indirect signals of daily routine disruption.
The logic is straightforward. If you normally charge your phone at roughly the same time each night and suddenly start charging at erratic hours, that entropy, the randomness of your behavior pattern, increases. Higher entropy across multiple behaviors can signal disrupted routines, which often accompany depressive episodes or increased impulsivity. Researchers extract features like usage frequency per hour, average duration of phone sessions, and the statistical spread of these behaviors over time to build individual baselines and detect deviations.
This approach is still largely in the research phase, but several mental health apps already incorporate simplified versions of passive tracking. The appeal is that it requires no effort from you: no questionnaires to fill out, no appointments to keep. The limitation is that behavioral data alone can’t tell you why a pattern changed, only that it did.
Putting Multiple Measures Together
No single measurement captures mental health completely, because mental health itself isn’t one thing. It spans emotional experience, cognitive sharpness, physiological stress responses, daily functioning, and social connection. The most useful approach combines at least two dimensions. A symptom questionnaire like the PHQ-9 paired with a functional measure like the WHODAS 2.0 gives you both the “how bad do I feel” and “how well am I managing” perspectives. Adding HRV tracking over time gives you a physiological trendline that’s independent of your subjective perception on any given day.
If you’re measuring for yourself rather than for a clinical diagnosis, consistency matters more than precision. Pick one or two tools, use them on a regular schedule (weekly or biweekly), and look for trends rather than fixating on any single score. A PHQ-9 score of 8 one week and 12 the next could reflect a bad day. A steady climb from 6 to 14 over two months tells you something real is shifting.