Depression Test: How to Know If You Have Depression

Everyone experiences low mood — periods of sadness, reduced motivation, and diminished pleasure that are a normal part of human experience. Clinical depression is something different: a persistent, pervasive condition that affects mood, cognition, physical functioning, and daily life in ways that go well beyond normal emotional variation. Understanding the difference, and knowing whether what you are experiencing warrants professional attention, is the first step toward getting appropriate support.

The Difference Between Low Mood and Clinical Depression

Normal low mood is typically:

• Linked to a specific cause (a difficult event, loss, stress)
• Proportionate to the circumstances
• Temporary — it lifts within days or a couple of weeks
• Improved by positive events or support from others
• Not pervasive across all areas of life

Clinical depression is typically:

• Persistent — lasting most of the day, nearly every day, for at least two weeks
• Pervasive — affecting multiple areas of life simultaneously (mood, energy, concentration, sleep, appetite, social functioning)
• Not reliably lifted by positive events (anhedonia — the inability to experience pleasure)
• Associated with a negative cognitive triad: persistently negative views of self, world, and future
• Functionally impairing — affecting work, relationships, and self-care

The key distinction is not how bad you feel at a single point in time, but the duration, pervasiveness, and impact on functioning. A single very bad day is not depression. Two weeks of persistent low mood affecting most areas of life, particularly if accompanied by anhedonia, warrants serious attention.

The PHQ-9: The Most Widely Used Depression Screening Tool

The Patient Health Questionnaire-9 (PHQ-9) is a validated 9-item self-report screening tool developed by Drs Robert Spitzer, Janet Williams, and Kurt Kroenke and validated in primary care settings. It is one of the most widely used depression screening instruments in the world, included in NICE guidelines for depression management and used across NHS primary care, research trials, and online therapy platforms including Online-Therapy.com.

The PHQ-9 asks how often over the last two weeks you have been bothered by each of the following:

1. Little interest or pleasure in doing things
2. Feeling down, depressed, or hopeless
3. Trouble falling or staying asleep, or sleeping too much
4. Feeling tired or having little energy
5. Poor appetite or overeating
6. Feeling bad about yourself — or that you are a failure or have let yourself or your family down
7. Trouble concentrating on things, such as reading the newspaper or watching television
8. Moving or speaking so slowly that other people could have noticed — or the opposite, being so fidgety or restless that you have been moving around a lot more than usual
9. Thoughts that you would be better off dead, or of hurting yourself in some way

Each item is scored 0 (not at all) to 3 (nearly every day), giving a total score of 0–27.

What Your PHQ-9 Score Means

• 0–4: Minimal or no depression — symptoms are within the normal range
• 5–9: Mild depression — symptoms are present and may warrant monitoring. Self-help CBT resources and lifestyle measures are appropriate starting points
• 10–14: Moderate depression — treatment is recommended. Online CBT with a licensed therapist is clinically appropriate and evidence-supported at this severity
• 15–19: Moderately severe depression — active treatment is strongly recommended. Online therapy may be appropriate; discuss with your GP if you have not already done so
• 20–27: Severe depression — in-person clinical assessment is recommended. Contact your GP or a mental health service. If there is immediate risk of harm to yourself, contact emergency services or a crisis line

Important: the PHQ-9 is a screening tool, not a diagnostic instrument. A high score indicates that depression is likely and warrants clinical attention — it is not a diagnosis. Similarly, a low score does not mean you should not seek support if you feel you need it. Clinical judgement, not a screening score alone, determines diagnosis and treatment.

The DSM-5 Criteria for Major Depressive Disorder

A formal diagnosis of Major Depressive Disorder (MDD) requires five or more of the following symptoms, present during the same two-week period, representing a change from previous functioning. At least one must be depressed mood or anhedonia:

• Depressed mood most of the day, nearly every day
• Markedly diminished interest or pleasure in all, or almost all, activities (anhedonia)
• Significant weight loss or gain, or decrease or increase in appetite
• Insomnia or hypersomnia
• Psychomotor agitation or retardation observable by others
• Fatigue or loss of energy
• Feelings of worthlessness or excessive or inappropriate guilt
• Diminished ability to think or concentrate, or indecisiveness
• Recurrent thoughts of death, suicidal ideation, or a suicide attempt

Symptoms must cause clinically significant distress or impairment and must not be attributable to the effects of a substance or another medical condition.

Other Forms of Depression to Know About

Persistent Depressive Disorder (Dysthymia): A chronic low-grade depression lasting two years or more. Symptoms are less severe than MDD but the persistent nature is significantly impairing. Often missed because it is mistaken for personality or temperament rather than a treatable condition.

Seasonal Affective Disorder (SAD): Depression with a seasonal pattern, typically emerging in autumn and winter and remitting in spring. Light therapy, CBT, and antidepressants all have evidence for SAD.

Postnatal Depression: Depression arising in the weeks and months after childbirth, affecting approximately 10–15% of new mothers and a smaller but significant proportion of fathers. Highly treatable with CBT and medication.

Bipolar Depression: Depressive episodes occurring within bipolar disorder require different treatment to unipolar depression — antidepressants alone can trigger manic episodes in bipolar disorder, making accurate diagnosis essential before treatment.

What to Do With Your Result

If your PHQ-9 score or self-assessment suggests mild-to-moderate depression:

• Consider starting a structured CBT programme with a licensed therapist — Online-Therapy.com's depression programme includes a validated screening assessment as an entry point and begins treatment immediately after
• Discuss your results with your GP, particularly if symptoms have been present for more than a few weeks or are affecting work and relationships
• Implement evidence-based lifestyle measures alongside therapy: regular physical exercise (strong evidence for moderate depression), sleep hygiene, and social connection all have meaningful effects on depressive symptoms

If your score is in the severe range (20+) or if you are experiencing suicidal thoughts, please contact your GP, a mental health crisis service, or emergency services. Do not wait for an online therapy appointment — seek in-person support immediately.