Recognizing the signs of depression

Depression isn't just “being sad.” It shows up as a cluster of symptoms that affect mood, but also the body, thinking, and behavior. Knowing them helps you recognize depression in yourself or a loved one, and avoid mistaking it for an ordinary bout of tiredness.

The criteria doctors use come from two international classification systems: the World Health Organization's ICD-11 and the American Psychiatric Association's DSM-5. They describe very similar symptoms, which the PHQ-9 questionnaire mirrors almost one by one.

The core symptoms

Two symptoms form the heart of the diagnosis. At least one of the two must be present nearly every day, for at least two weeks:

• A sad, empty, or hopeless mood, present most of the day
• A marked loss of interest or pleasure in previously enjoyed activities, which doctors call anhedonia

Anhedonia is often less well known than sadness, even though it's just as important. Some people with depression don't feel particularly sad: they describe instead an emptiness, an indifference, the impression that nothing tastes good anymore. A favorite dish, music, friends, hobbies no longer bring any pleasure, and people sometimes keep doing them out of habit, feeling nothing. This detachment can come with guilt, particularly toward one's children or partner.

The associated symptoms

Around this core, other symptoms round out the picture:

• Sleep disturbances: insomnia or, conversely, excessive sleep
• Fatigue or unusual loss of energy
• Changes in appetite or weight, in either direction
• Difficulty concentrating or making decisions
• Feelings of worthlessness or excessive guilt
• Slowing down or agitation visible to others
• Thoughts of death or suicidal ideas

These symptoms take concrete forms in daily life. For sleep, a typical sign is waking up very early in the morning, with ruminating thoughts, and feeling at your lowest early in the day. Fatigue means that the simplest tasks, showering, replying to a message, running errands, require considerable effort. Concentration problems show up as pages read without retaining anything, forgetfulness, decisions put off. The feeling of worthlessness often takes the form of a harsh inner voice: “I'm useless,” “I'm a burden to others,” “it's all my fault.”

Thoughts of death deserve particular attention. They range from the idea that life isn't worth living, or the wish not to wake up, to more specific suicidal ideas. They are part of the symptoms of the illness, not a considered choice, and they lessen with treatment. This is why the PHQ-9 includes a question on this topic, and why the Hygietest tool immediately displays help contacts if you answer it with anything other than “never.” If these thoughts are present, it's important to talk about them quickly: in France, 3114 responds free of charge day and night, for you as well as for those close to you — outside France, look up your local equivalent (in the US, 988).

To diagnose a depressive episode, doctors look for at least five symptoms from this list, including at least one of the two core symptoms. The number and intensity of symptoms, as well as their impact, are used to classify the episode as mild, moderate, or severe.

An important difference from an ordinary low mood

What sets depression apart from ordinary passing sadness is its duration, at least two weeks almost continuously, its intensity, and above all its concrete impact on daily life.

Sadness is a normal, useful emotion. After a disappointment, a breakup, or a failure, it's natural to feel down for a few days. But this sadness fluctuates: it eases around loved ones, during a good moment, or when the situation improves. In depression, mood stays low regardless of circumstances, and good news no longer manages to lift it.

Grief is a special case. It's normal to feel intense sadness after losing someone close, sometimes for several months, with waves of grief. In grief, self-esteem is usually preserved, and the pain is centered on the person who died. When a general sense of worthlessness, a lasting inability to function, or suicidal thoughts are added on top, depression may have set in, and it's worth talking about it.

Sometimes different presentations depending on the person

Depression doesn't always look the same. Some people express more irritability or agitation than the expected sadness, particularly men and teenagers.

In men, depression often shows up as anger, impatience, unusual risk-taking, increased alcohol use, or overinvestment in work. These signs are less easily recognized as depression, including by the person themselves. The Is my alcohol consumption risky? test can be useful if alcohol is being used to numb distress.

In teenagers, irritability, withdrawing to their room or into screens, falling grades, and dropping sports or friends are frequently observed.

In older adults, depression often shows up as physical complaints (pain, fatigue, loss of appetite), memory problems that can be mistaken for dementia, or a loss of interest presented as “normal at that age.” It is not, however, a normal consequence of aging, and it can be treated at any age.

After childbirth, postpartum depression is estimated to affect more than one woman in ten, according to the WHO. It differs from the “baby blues” of the first few days, which goes away on its own within one to two weeks. Sadness, anxiety, or exhaustion that persists beyond that is worth mentioning to a midwife, doctor, or maternal and child health service.

Finally, physical symptoms are common in all forms: headaches, diffuse pain, digestive problems, chest tightness. Many people first seek care for these symptoms, without connecting them to their mood. Anxiety also very often accompanies depression.

Why duration matters as much as intensity

A depressive episode is also marked by its relative continuity: symptoms are present most of the time over the period. This is why the PHQ-9 asks how often each symptom was present over the past two weeks, from “never” to “nearly every day.”

Duration matters in the other direction too. A mood that has been somewhat low for two years or more, without being very intense, can correspond to a chronic form called dysthymia, or persistent depressive disorder. It often goes unnoticed, as the person ends up believing “that's just how I am,” when in fact it can be relieved by treatment.

Other causes can mimic depression: a thyroid disorder, anemia, certain medications, sleep apnea, burnout. A medical workup can check for these. The Am I burned out? and Do I have sleep apnea? tests can complement the assessment. It's also important to mention to your doctor any past periods of elation, overflowing energy, or a much-reduced need for sleep, as they point toward bipolar disorder, whose treatment is different.

Loved ones have a valuable role to play. They often notice the change before the person themselves does: withdrawal, irritability, loss of interest, constant fatigue. Expressing concern with kindness, without judging or minimizing, and offering to go with the person to see a doctor can make a real difference.

To assess your symptoms, take the “Am I depressed?” test.