Low mood: how long it usually lasts, what research around it finds and what a wellbeing scan measures

In this article you read what low mood usually looks like, how long it usually lasts, what research finds around it and what a wellbeing scan can and cannot measure. That matters, because low mood is common: in 2023, 13.7 per cent of people in the Netherlands aged 12 and over had mental health complaints in the four weeks before the interview.⁠² It also matters because low mood is hard to read from the inside, where your memory flattens out how the past month really felt. BioProfile’s wellbeing scan measures how much these complaints affect you, and gives you an indication of where you stand today in this area, as the first of the 11 health areas the full scan assesses. This is not a diagnosis. It is insight, to see where you stand today. And to help you make better choices in your food and your lifestyle. What this scan does not do: point to a cause or make a diagnosis. Only a doctor can do the latter.

How long low mood usually lasts

Thuisarts, the patient information of the Nederlands Huisartsen Genootschap, describes a low mood as something that usually passes after a few weeks or months, with grief after a big loss lasting longer.⁠¹ The same page names what makes a low mood worth an appointment: a low mood that stays and loss of interest, together with complaints such as sleeping badly, restlessness or feelings of worthlessness.⁠¹

That is the first usable dividing line. A grey patch of a few weeks is normal. Weeks on end, with the interest gone and night after night broken, belongs in the consulting room.

How often it occurs in the Netherlands

The national figure of 13.7 per cent is measured with the MHI-5 in the CBS Gezondheidsenquête, was last updated on 12 March 2024, and is no longer updated since the recalibration of the MHI-5 cut-off point in 2024.⁠² Another Dutch study did it person to person: for NEMESIS-3, 6,194 people aged 18 to 75 were interviewed at home between November 2019 and March 2022, with a response of 54.6 per cent.⁠⁴ Among people aged 18 to 64, the share with a mental disorder in the twelve months before the interview rose from 17.4 per cent in 2007-2009 to 26.1 per cent in 2019-2022, and that share did not differ between the people interviewed before the pandemic (26.7 per cent) and during the pandemic (25.7 per cent).⁠⁴

In plain words: about one in four adults falls under that definition in a given year, and the rise was already under way before the pandemic. Low mood puts you in very ordinary company.

What research around a low mood finds

Sleep is the most studied piece. A meta-analysis brought together 1,338 effect sizes from 154 experiments with 5,717 healthy participants aged 7 to 79, covering everything available up to December 2022. Every form of sleep loss studied (a night awake, shorter sleep, broken sleep) went together with fewer positive feelings such as joy, cheerfulness and contentment (standardised mean differences of -0.27 to -1.14), with more anxiety complaints (0.57 to 0.63) and with a flatter response to emotional stimuli (-0.20 to -0.53).⁠⁵ These were experiments, so the direction is clear: take sleep away from people who are healthy, and the good feelings go first.

Daylight comes next. In UK Biobank, more than 400,000 British adults aged 37 to 73 (54 per cent women, enrolled between 2006 and 2010, with an extra mental health questionnaire in 2016 and 2017) spent a median of 2.5 hours a day outdoors in daylight (interquartile range 1.5 to 3.5 hours). Each extra hour a day went together with a lower chance of feeling low (odds ratio 0.88; 95 per cent confidence interval 0.87 to 0.90) and of taking less pleasure in things (0.95; 0.93 to 0.96), and with a higher chance of feeling happy (1.45; 1.41 to 1.48) and of finding it easier to get up in the morning (1.47; 1.46 to 1.49).⁠³ These are associations within one large group. Even so, an hour outdoors is the cheapest point on this list.

Companionship is the third piece. Among Dutch adults aged 18 to 64, 10.9 per cent were severely lonely in 2025 on the shortened De Jong Gierveld scale, a share that moved between 9.0 per cent (2019) and 11.8 per cent (2021). The share was highest at 35 to 44 years (12.6 per cent) and lowest at 55 to 64 (9.1 per cent), and ran from 17.0 per cent among people with only primary education to 7.2 per cent among people with a university education.⁠⁶ Loneliness is spread unevenly across ages and education levels, and the middle stage of life carries the largest part of it.

What you can do yourself

Thuisarts advises fixed times for getting up, eating and sleeping, going outside every day, about 30 minutes of movement a day such as walking, cycling or sport, using no alcohol or drugs, and talking to the people around you.⁠¹ The Gezondheidsraad puts the movement figure for adults at at least two and a half hours a week, so 150 minutes, of moderately intensive activity, with muscle and bone strengthening exercises alongside it, and at least an hour a day for children.⁠⁷

Exercise has the largest dataset. Among 1.2 million American adults in national health surveys between 2011 and 2015, people who exercised reported 1.49 fewer days a month of poor mental health than comparable people who did not, a difference of 43.2 per cent; every form studied came out 11.8 per cent to 22.3 per cent lower than no exercise at all, with team sports (22.3 per cent), cycling (21.6 per cent) and aerobics or gym work (20.1 per cent) the strongest. The link was strongest at sessions of about 45 minutes, three to five times a week, and less favourable above 23 sessions a month or above 90 minutes.⁠⁸ So the useful dose is very ordinary: three to five short sessions a week, in company where that is possible.

Where you walk has been studied separately. 38 healthy participants (18 women, average age 26.6) each made one walk of 90 minutes, half through grassland and oaks, half along a busy traffic road in Palo Alto. Among the walkers in the green, dwelling on their own problems fell by an average of 2.33 points (t(17) = -2.69; p < 0.05), while the score of the walkers along the road stayed where it was.⁠⁹

Food has been studied over a short period. 171 young adults aged 18 to 25 who ate little fruit and vegetables took part in a randomised study of 14 days; the group given two extra portions of fresh fruit and vegetables a day ate about 1.2 portion more than at the start and reported more vitality and more flourishing than the two other groups, with an intake that still lay below the recommended amount.⁠¹⁰ A small study, young people, two weeks: read it as a nudge rather than a rule.

When to make an appointment

Make an appointment with your GP if low mood and loss of interest persist, along with complaints such as poor sleep, restlessness or feelings of worthlessness. Call straight away in a mental health crisis, or if you have thoughts of suicide with plans; Thuisarts points to 113, reachable day and night and free.⁠¹

What a wellbeing scan measures and what the scan does not measure

The wellbeing scan asks a short set of questions about how the past two weeks went, and converts the answers into a wellbeing score with the reading band it falls in. Higher is better. The questions are worded by us, so the score is not a validated clinical score; the national figure above is measured with the MHI-5, a validated instrument in the CBS Gezondheidsenquête.⁠²

A questionnaire cannot say what causes a low mood. Short sleep, loneliness, few hours of daylight, grief and depression can all read almost the same in a set of questions. What the scan gives you is a starting value, and a second number if you repeat the scan two weeks later. What causes the mood is a question for a doctor. The scan is not a diagnosis.

In summary

A low mood is common, usually passes within weeks or months, and the guideline for patients is clear about the point where it belongs in the consulting room. Around it, the best measured pieces are sleep, daylight, exercise, company and, on a small scale, what you eat. A wellbeing scan gives you a number to start from and a way to see movement over two weeks. Pointing to a cause is work for a doctor. The scan is not a diagnosis.