How to improve concentration: why you can’t focus and what research says helps

Attention is not constant; it fluctuates from moment to moment (Esterman & Rothlein, 2019). In tasks that involve watching for rare signals over a long time, people detect fewer of them as time goes on. This is called the “vigilance decrement”, and it showed up in the first major laboratory studies in 1948 (Klein & Feltmate, 2025). Holding attention like this, known as sustained attention, looks undemanding, but behavioural, neural and subjective measures agree that it is hard mental work and stressful (Warm et al., 2008).

Mind-wandering is also very common. In a study that used an iPhone app to ask people at random moments while awake “Are you thinking about something other than what you’re currently doing?”, 46.9% of the answers from 2,250 adults were moments of mind-wandering, and it was at least 30% during almost every activity. They were volunteers who had downloaded the app, and 73.9% lived in the US. The researchers read their time-lag analyses as strongly suggesting that mind-wandering was generally a cause of unhappiness, not merely a result (Killingsworth & Gilbert, 2010), but a 2025 study that revisited this in 337 people found that much of the link between mind-wandering and mood was explained by what the thoughts were about, pleasant or unpleasant (Gross et al., 2025).

More mind-wandering tends to go with lower task performance, especially on complex tasks. This comes from a meta-analysis of 88 correlations in general adult samples, so it does not show cause and effect (Randall et al., 2014). During demanding tasks that required concentration, people with greater working memory capacity mind-wandered less in one study (Kane et al., 2007). On the other hand, a review notes that mind-wandering has costs, being linked with errors, but is also linked with creativity and planning for the future, so it brings both costs and benefits (Smallwood & Schooler, 2015).

The often-quoted “attention span” is not a single fixed number either. A review of studies on students’ attention in lectures concluded that primary data do not support the idea of a 10- to 15-minute limit, and that students’ attention varied more between teachers than between teaching formats (Bradbury, 2016). A researcher interviewed by the BBC’s statistics programme also said that attention span depends very much on the task (BBC, 2017).

Sleep is one of the biggest influences on concentration. In a meta-analysis of 70 articles (147 cognitive tests) on people going without sleep for one night or more (under 48 hours), comparing each study’s baseline with the point of longest wakefulness showed the largest rise in lapses on simple attention tasks (g = −0.776), while reasoning accuracy did not differ clearly (Lim & Dinges, 2010). Japan’s Ministry of Health, Labour and Welfare sleep guide also explains that lack of sleep lowers attention and judgement and can reduce work efficiency and school performance (Ministry of Health, Labour and Welfare, 2024).

Short sleep night after night has similar effects. In an experiment that assigned 48 healthy adults to 4, 6 or 8 hours in bed per night for 14 days, or to going without sleep, those who spent 2 weeks at 6 hours or less showed performance deficits equivalent to up to 2 nights without any sleep, yet their sleepiness ratings did not rise as much, which suggests they were largely unaware of it (Van Dongen et al., 2003). A meta-analysis of 61 sleep-restriction studies also found lower sustained attention (g = −0.409; Lowe et al., 2017). The American Academy of Sleep Medicine and the Sleep Research Society recommend that adults aged 18 to 60 regularly sleep 7 hours or more, while noting that sleep need varies from person to person (Watson et al., 2015).

Stress plays a part too. In a meta-analysis of laboratory studies that induced short-term stress, stressed conditions showed slightly lower working memory (34 studies, 1,353 people; g = −0.197) and cognitive flexibility (6 studies, 280 people; g = −0.300) than comparison conditions, while inhibition did not differ clearly (Shields et al., 2016). These are results for brief laboratory stress; long-running everyday stress is covered in stress relief.

Low mood and worry also make it hard to concentrate. A meta-analysis found that people with depression had moderate deficits in executive function, memory and attention compared with healthy controls (d −0.34 to −0.65), and that differences in executive function and attention remained after symptoms had eased (Rock et al., 2014). Difficulty concentrating is among the symptoms of generalised anxiety disorder, but most people feel anxious sometimes, and that does not always mean they have the disorder (NHS, 2024b). The depression check-in (PHQ-9) also has an item on “trouble concentrating on things, such as reading the newspaper or watching television”. If mood problems come with it, see depression symptoms and anxiety symptoms.

ADHD can be one reason, but not everyone who struggles to focus has ADHD. The NHS explains that ADHD symptoms usually start before the age of 12 (NHS, 2025a), and a meta-analysis of adult studies, adjusted to the world’s 2020 population structure, estimated 2.58% using criteria that require onset in childhood (Song et al., 2021). Physical conditions such as an underactive thyroid (NHS, 2025c), the menopause (NHS, 2026) and long COVID (NHS, 2025b) can also make concentrating hard. For more, see adult ADHD symptoms and “When to see a doctor” below.

Notifications can genuinely break your focus. In one experiment, receiving a phone notification alone, without touching the phone, clearly disrupted performance on an attention-demanding task (Stothart et al., 2015). When 221 adults from the general population spent one week with alerts on and the phone within reach and another week with alerts off and the phone out of reach, they reported more inattention and hyperactivity symptoms in the week with alerts on (Kushlev et al., 2016). These were self-reported symptoms, not ADHD diagnoses.

The claim that “just having your phone nearby makes your mind work less well” came from two experiments in 2017 (Ward et al., 2017). But a pre-registered direct replication of the second experiment, in which the phone was on the desk, in a pocket or bag, or in another room, found no difference by location (Ruiz Pardo & Minda, 2022). Reviews of the studies also point to small or no effects. An analysis of 22 studies on whether using a phone or merely having it nearby lowers performance found a small overall effect (g = −0.14), clear only for memory and not for attention (Böttger et al., 2023). A review with six meta-analyses covering 7,093 people found an effect, smaller than theorised, only on working memory (Parry, 2024), and an analysis of 33 studies (4,368 people) found no significant effect (d = −0.02; Hartanto et al., 2024).

Switching between tasks has a cost. Right after a switch, responses are substantially slower and usually more error-prone, and a chance to prepare reduces this cost without removing it (Monsell, 2003). A 2009 study found that heavy media multitaskers were more easily distracted by irrelevant stimuli (Ophir et al., 2009), but later laboratory replications mostly did not confirm it. In two replication studies only 5 of 14 tests showed the effect, and a meta-analysis of 39 effects found a weak link that became non-significant after correcting for small-study bias (Wiradhany & Nieuwenstein, 2017). A meta-analysis of 118 assessments also found the overall link small: results with methods close to the original study did not hold up, but studies that asked people about everyday executive functioning consistently found a negative link (Parry & le Roux, 2021). Which causes which is still unknown (Uncapher & Wagner, 2018).

The idea that “people’s attention spans are getting shorter” is also weakly supported. The time a hashtag stayed in Twitter’s top 50 fell from 17.5 hours on average in 2013 to 11.9 hours in 2016, but this is how fast society’s collective attention moves on to the next topic, not how long one person can concentrate (Lorenz-Spreen et al., 2019). One review suggests that the constant stream of online information may divide attention and get in the way of sustained concentration, but this is still at the “may” stage (Firth et al., 2019). Ways to cut down on phone use are in smartphone overuse.

The first thing to look after is sleep. As shown above, lack of sleep shakes simple attention the most (Lim & Dinges, 2010). Next is cutting down on interruptions. In a randomised field experiment with 237 people, those whose notifications were batched three times a day felt more attentive, productive, in a better mood and in greater control of their phones than those receiving them as usual, and reported lower stress, whereas those who received no notifications at all reaped few of those benefits and had higher anxiety and FoMO (Fitz et al., 2019). When starting a task you keep putting off, an implementation intention, a plan of when, where and what in the form “if X, then I will do Y”, may help. In a meta-analysis of 94 studies, people who made such plans reached their goals to a medium-to-large degree more than people who only set goals (d = 0.65; Gollwitzer & Sheeran, 2006; Rozental et al., 2018).

Short breaks can help too. In a meta-analysis of 22 samples (2,335 people) testing breaks of under 10 minutes, breaks raised vigour (d = .36; 9 studies, 913 people) and reduced fatigue (d = .35; 9 studies, 803 people) compared with control groups that took no break, but the improvement in overall performance was not statistically significant (d = .16; 15 studies, 1,132 people). Performance gains were clear only for less demanding tasks, and the longer the break, the larger the gain (Albulescu et al., 2022). The Pomodoro technique, 25 minutes of focus and a 5-minute break, has only a few small experiments behind it, with mixed results. In one, students who took breaks at fixed intervals reported less fatigue and distraction than those who took breaks when they chose (Biwer et al., 2023); in another, Pomodoro breaks led to a faster rise in fatigue (Smits et al., 2025); in a third, self-chosen breaks led to better mood and concentration than short fixed breaks (12 minutes of reading, 3 minutes of rest) (Göksu et al., 2026); and none found a difference in how much was done or learned. The authors of the third noted that their learning measure may not have been sensitive enough to show a difference.

Exercise helps less than people expect. Many studies find that cognitive performance improves a little after a single session, but the effect was small (79 studies, g = 0.097; Chang et al., 2012), and a review for the US physical activity guidelines rated the brief benefit right after moderate-to-vigorous exercise as strong evidence (Erickson et al., 2019). The effect of regular exercise in healthy people was small across 80 randomised controlled trials (Ludyga et al., 2020), and a re-analysis of the randomised trials in several meta-analyses found the effect compared with control groups shrank from d = 0.22 to 0.13 after accounting for active control groups and baseline differences, and to 0.05, almost nothing, after correcting for publication bias (Ciria et al., 2023). So there is little basis for expecting that “exercise will greatly improve your concentration”.

Time in nature has mixed results. In a review of 31 studies comparing natural with non-natural or other settings, only 3 of 13 analyses of attention-related tests showed a clear benefit of nature (Ohly et al., 2016), and a review of 42 articles that compared nature with a suitable control found low-to-moderate gains in working memory and cognitive flexibility, with attentional control less reliable (Stevenson et al., 2018). In a review of 56 randomised trials (2,931 people) of mindfulness programmes, 45 of which (2,238 people) were pooled in a meta-analysis, there were small effects on executive function and working memory, but programmes beat only groups that did nothing, not groups that did another activity, and no effect was found on attention tests (Whitfield et al., 2022). If you want to try meditation, see meditation and mindfulness.

A review concludes that caffeine raises alertness and simple attention, but that effects on memory and on higher executive functions such as judgement and decision-making are less consistent (McLellan et al., 2016). One study suggests that for daily drinkers, part of the alerting effect may be reversing overnight withdrawal: among its 379 participants, those who usually drank little or none did not become more alert with caffeine (Rogers et al., 2010). Korea’s Ministry of Food and Drug Safety gives maximum daily intakes of 400 mg for adults, 300 mg in pregnancy and 2.5 mg per kg of body weight for children and teenagers, and advises cutting down or stopping if palpitations, headaches, anxiety or sleep problems appear even within those limits, and avoiding caffeine in the late afternoon and evening (Ministry of Food and Drug Safety, 2026a). The European Food Safety Authority likewise sees no safety concern for healthy adults taking up to 400 mg a day spread over the day, but sets 200 mg a day in pregnancy (EFSA, 2015). How caffeine affects sleep is covered in insomnia: what helps.

Music while studying depends on the task. In a meta-analysis of 65 studies on reading, noise, speech and music all slightly lowered reading comprehension compared with silence (g = −0.21), and music with lyrics was very probably more distracting than music without (Vasilev et al., 2018). Another meta-analysis comparing background music with no music found it slightly worse for reading and memory, but good for mood and for sports performance (Kämpfe et al., 2011). White or pink noise slightly improved task performance compared with low or no noise in studies of children and college-age young adults with ADHD or ADHD symptoms (13 studies, 335 people; g = 0.249), but slightly worsened it in comparison groups without ADHD (11 studies, 335 people; g = −0.212; Nigg et al., 2024). That the best time of day to concentrate may differ between people is covered in Morning people and night owls.

Playing brain or focus games makes you better at those games and very similar tasks, but there is little evidence that this carries over to everyday focus or study. A review that evaluated brain-training studies found extensive evidence that trained tasks improve but little evidence of gains on distantly related tasks or in everyday cognition (Simons et al., 2016), and working memory training reliably raised working memory scores right after training, but showed no reliable improvement on far measures such as verbal and nonverbal ability, reading and arithmetic when compared with a control condition that did another activity (Melby-Lervåg et al., 2016). An analysis that brought the meta-analyses together found that, once placebo effects and publication bias were controlled for, the effect on distant tasks (far transfer) was zero (Sala et al., 2019; Gobet & Sala, 2023).

“Focus supplements” also have weak evidence. In randomised trials of ginkgo extract in healthy people, there was no effect on attention compared with placebo (8 trials, 910 people, d = −0.08; Laws et al., 2012). In 24 studies of omega-3 supplements, cognitive performance did not improve, except short-term memory in people whose omega-3 levels were low to begin with (Cooper et al., 2015). In children and teenagers with ADHD, there was high-certainty evidence that polyunsaturated fatty acids such as omega-3 had no effect on total parent-rated ADHD symptoms (Gillies et al., 2023). The US National Center for Complementary and Integrative Health notes that ginkgo may increase the risk of bleeding in people taking anticoagulants such as warfarin (NCCIH, 2025). In checks before the 2025 university entrance exam, Korea’s Ministry of Food and Drug Safety caught 45 online posts that advertised foods and health supplements misleadingly with words such as “exam student supplement”, “memory” and “concentration” (Ministry of Food and Drug Safety, 2025).

There is no “study drug” either. A meta-analysis of 48 studies (1,409 participants) that gave prescription stimulants to healthy people concluded that their effect on cognition is probably modest overall, and that healthy users may take them more for energy and motivation than for cognition (Ilieva et al., 2015). Meta-analyses comparing these drugs with placebo in healthy adults who were not short of sleep also found small effects in experiments that do not reflect how the drugs are actually used (Roberts et al., 2020). Korea’s Ministry of Food and Drug Safety warns that taking an ADHD medicine (methylphenidate) without having the condition can cause side effects such as headaches, anxiety and, in severe cases, hallucinations (Ministry of Food and Drug Safety, 2026c), and that buying it online without a prescription or taking medicine that family or friends got prescribed or bought on your behalf breaks Korea’s Act on the Control of Narcotics (Ministry of Food and Drug Safety, 2026b). For people who do have ADHD, prescribed medicine is an effective treatment, which is a separate matter (adult ADHD symptoms). If you are worried about drug misuse, see drug use: what helps.

If someone suddenly becomes confused, struggles to pay attention or cannot remember things, get medical help immediately (NHS, 2024a). In Korea, call 119; elsewhere, call your local emergency number.

Losing focus now and then is common. The NHS advises seeing a GP if memory problems keep happening or affect daily life, and not trying to self-diagnose the cause (NHS, 2023a). It also advises seeing a GP if you have symptoms of depression for most of the day, every day, for more than 2 weeks (NHS, 2023b). The depression check-in (PHQ-9) and the anxiety check-in (GAD-7) let you look back over the past 2 weeks, but they are not diagnoses.

If trouble concentrating has been there since childhood, in several settings, and affects your studies, work or relationships, you can ask for an assessment. Doctors may also consider other conditions that could cause similar symptoms, such as autism, Tourette’s or anxiety (NHS, 2025a). Difficulty concentrating or thinking clearly is a symptom of an underactive thyroid; because such symptoms are common and can have other causes, it is important to get them checked by a GP (NHS, 2025c). During the menopause you may notice problems with memory or concentration, which can feel worse with poor sleep and great tiredness (NHS, 2026), and long COVID can leave problems with memory and concentration, also called brain fog (NHS, 2025b).

“Brain fog” is not a diagnosis but an everyday term that bundles together many difficulties. In a study of online posts, the 141 first-person descriptions people gave under this term mixed forgetfulness (51), difficulty concentrating (43), dissociative experiences (34) and more (McWhirter et al., 2023), and a neurology review also notes that patients use it for a very wide range of symptoms (McWhirter, 2025). If it is your first visit, see seeing a psychiatrist for the first time; if memory is your bigger worry, see forgetfulness.

Myth 1: Our attention span is now 8 seconds, shorter than a goldfish’s. When the BBC traced it, the figure had spread through a 2015 consumer report by Microsoft Canada, but the report only cited another website, and the organisations that website named as its sources could find no research behind the figures. There was no evidence either that goldfish have particularly short attention spans or memories (BBC, 2017). Even for lectures, a fixed 10- to 15-minute limit is not supported by the data (Bradbury, 2016).

Myth 2: Good multitaskers get more done. Every switch between tasks brings a switch cost, with slower responses and more errors (Monsell, 2003). In a driving-simulator study in which 200 people drove while doing a demanding memory task, only 2.5% showed no drop in performance at all (Watson & Strayer, 2010).

Myth 3: Just having your phone nearby makes your mind work worse. The second experiment behind this claim did not replicate when it was repeated exactly (Ruiz Pardo & Minda, 2022), and reviews of the studies point to no effect or a small one (Böttger et al., 2023; Parry, 2024; Hartanto et al., 2024). Things that actually grab your attention, such as notifications, are a different matter (Stothart et al., 2015).

Myth 4: Mozart or white noise boosts everyone’s concentration. The “Mozart effect” began with an experiment in which spatial-task scores rose after listening to Mozart, but it was later put down to underpowered studies and measurement bias (Oberleiter & Pietschnig, 2023). White and pink noise slightly worsened performance in comparison groups without ADHD (Nigg et al., 2024).

Myth 5: If you can’t focus, you have ADHD. There are many reasons for poor focus, such as sleep, stress, mood and physical health. ADHD symptoms usually start before the age of 12, and an assessment may also consider other conditions that can cause similar symptoms (NHS, 2025a). Don’t diagnose yourself from poor focus alone; if you are wondering, read adult ADHD symptoms.

Q. Is there a concentration test? A. mind.io has no test that measures concentration or ADHD. The depression check-in (PHQ-9) has an item on trouble concentrating, but it is a tool for looking back on your mood, not a diagnosis.

Q. Does zoning out help? A. Some studies find that people who rested quietly for a few minutes after learning something remembered it better later than people who did another task. A meta-analysis of 37 studies found this effect (g = 0.448), and it was still there after 7 days (g = 0.270; Weng et al., 2025). But in a pre-registered replication the effect was not significant on its own, and the benefit may require a resting state free even of daydreaming (Humiston et al., 2019). These are studies of memory, not of concentration, and resting is not the same as looking at your phone.

Q. Does coffee help me concentrate, and how much is safe in a day? A. Alertness and simple attention can improve (McLellan et al., 2016), but stay within the Korean Ministry of Food and Drug Safety’s limits above and avoid caffeine in the late afternoon and evening (Ministry of Food and Drug Safety, 2026a). Japan’s Ministry of Health, Labour and Welfare explains that, because individual differences are large, no acceptable daily intake that would be harmless over a lifetime has been set in Japan or internationally (Ministry of Health, Labour and Welfare, n.d.).

Q. How often should I take a break? A. There is no fixed number. In a 1958 vigilance experiment, responses grew slower over a 40- to 50-minute session, and a break after 40 minutes sped them up again, more so after a longer break (Klein & Feltmate, 2025). A meta-analysis of short breaks also found that longer breaks went with bigger performance gains (Albulescu et al., 2022), but neither gives a rule to apply directly to everyday study.

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