What low mood usually looks like
Low mood is a response. Something happened — a rejection, a fight, a long stretch of overwork, a grey February — and you feel flat. The NHS describes low mood as including sadness, worry, tiredness, low confidence and frustration, and notes that it usually lifts after a few days or weeks.
The tell is that it still responds. A friend calls and for an hour you are fine. You laugh at something. You eat a good meal and notice it. The feeling is heavy but it is not sealed.
Low mood also tends to stay in its lane. You are sad about the thing. You are not sad about everything, and you have not stopped being able to do the ordinary parts of your day.
What depression looks like
Depression is less like intense sadness and more like a flattening. The American Psychiatric Association describes it as a persistent low mood or loss of interest in activities that were previously enjoyed, present most of the day, nearly every day, for at least two weeks, together with changes in sleep, appetite, energy, concentration or sense of self-worth.
The loss of interest is the part people miss in themselves. Sadness hurts. Depression often does not hurt so much as it goes quiet — the things that used to matter simply stop pulling on you. People describe it as watching their own life from a seat further back.
It also travels with the body. Sleep goes wrong in either direction. Appetite changes. Getting up takes an amount of effort that would be absurd to describe out loud. Concentration frays, so reading a page twice becomes normal.
And it is common. The World Health Organization estimates that around 5 percent of adults live with depression, and the National Institute of Mental Health has put the number of US adults with at least one major depressive episode in 2021 at 21.0 million, or 8.3 percent of adults. Whatever this is, you are not an unusual case.
The three questions that separate them
None of these is diagnostic. All three are what a clinician will ask you in the first two minutes.
- How long? A few days is a bad patch. Most of the day, nearly every day, for two weeks or more is the threshold health services use before they call it something else.
- How much has it taken? Low mood makes things harder. Depression removes things — the hobby, the messages you used to answer, the meals you used to cook, the person you used to be with people.
- Does it move? If a genuinely good afternoon lifts it for a while, that is a different picture from an afternoon that changes nothing at all.
The things that are not the difference
It is not about whether you have a reason. Depression that arrives after a real loss is still depression, and depression that arrives with no explanation is still real. Having a reason does not disqualify you from help.
It is not about how bad you have it compared with other people. That comparison is the single most reliable way to talk yourself out of an appointment, and it is not a clinical criterion anywhere.
It is not about whether you can still function. Plenty of people hold down demanding jobs while depressed. Managing to work is not evidence that nothing is wrong; it is often evidence that everything else has been dropped to protect the working hours.
When to talk to someone
The NHS advice is straightforward: if you have been feeling down for more than two weeks, see a GP. That is the whole rule, and it does not require you to have decided what is wrong first.
Talk to someone sooner than that if the low mood came with a big change in sleep or appetite, if you have stopped doing things you used to need, if drinking or anything else has crept up, or if you are having thoughts of being better off dead. That last one is not a two-week rule. That is tonight: call or text 988 in the US, call Samaritans on 116 123 in the UK and Ireland, or find your local line at findahelpline.com.
What to actually say, if the words are the obstacle: "I've been feeling low for about six weeks. I'm sleeping badly and I've stopped doing things I used to like. I'd like some help." That is enough. You will not be asked to prove it.
What to do while you wait for the appointment
Appointments take time. The gap is where most people give up, so it helps to have something small and specific to hold on to in it.
Take inventory of your life rather than your mood. Not "how bad am I today" but "what has actually gone": the walk, the friend, the cooking, the room you used to like sitting in. A list of missing pieces is far more useful to a clinician than an adjective, and it is far more useful to you, because a missing piece can be reached for and a mood cannot.
This is the difference between the tools people reach for here. A mood tracker records how you felt. A questionnaire scores how much symptom you have. Neither one tells you what to do on Tuesday. DepreScan is the loop that turns a snapshot into movement: it screens, it never diagnoses, and then it gives you one small step a day aimed at whichever part of your life has slipped furthest.
Questions people ask
How long does low mood have to last before it is depression?
Two weeks is the line health services work from. The diagnostic criteria the American Psychiatric Association describes require symptoms to be present most of the day, nearly every day, for at least two weeks, and NHS guidance is to see a GP if you have been feeling down for more than two weeks. Two weeks is not a magic number; it is the point at which it stops being reasonable to wait and see.
Can you be depressed and still laugh at things?
Yes. People with depression still laugh, still have good hours, and still show up for the people who need them. Clinicians see this constantly and it does not rule anything out. What matters more is whether those moments lift the whole day or disappear as soon as they end, and whether the flat feeling comes back the moment you are alone.
Is there a test that tells you which one it is?
No. Screening questionnaires like the PHQ-9 measure how much symptom you have reported over two weeks, and a score of 10 or more is usually the point at which a clinic looks properly. But screening is not diagnosis: only a health professional can put the score together with your history, your physical health, your medications and your circumstances and say what is going on.
What if I have a good reason to feel this way?
Having a reason does not make it less real or less treatable. Grief, a breakup, a job loss and a long illness can all be genuine causes and can all sit alongside depression. Clinicians are used to untangling that, and none of them will tell you your reason disqualifies you. If it has lasted more than two weeks and taken things from your life, it is worth an appointment either way.
Should I wait to see if it passes on its own?
Waiting a few days when something specific has upset you is reasonable. Waiting weeks while sleep, appetite and the things you used to enjoy quietly disappear is not, and it is the pattern most people regret. The World Health Organization notes that effective treatments for depression exist and that most people who need them do not receive them, largely because they never get seen.