If you're experiencing burnout (i.e. this is affecting your health, your general mental state, your social life or other parts of your life), go see a doctor. Burnout is serious and can result in long-term damage unless treated appropriately. The below should not be considered alternatives to getting professional medical treatment.
Many of the points below are important to prevent burnout or deal with mental fatigue, but they can also help improve productivity (and happiness) in general.
I would recommend trying some or all of these things, even if not doing them has never been a problem before. Suffering from mental fatigue isn't exactly normal circumstances.
As quite excellently noted by the author of the question in a comment:
This serves as a great checklist-style starting point for a plan of lifestyle change. Primarily, it is a prompter for numerous reasonable considerations that may (or may not) contribute to the mental fatigue. It is then in the reader's hand to reach his own conclusions about what applies to him, what of the advice to take, and what lifestyle-changes to pursue. Implicitly, none of this replaces medical attention or treatment - if the same is required, it is again up to the reader's discretion to seek it.
Exercise, Socialise, Maintain a healthy diet
While any given person may not much like or see the value in any or all of these things, they're hugely important to general mental health.
I'm no expert, but I would recommend, at the very least:
- Exercising twice a week for at least 30 minutes.
- Taking at least a 10-20 minute walk every day (the fresh air and sunlight helps a lot too).
- Speaking to another human being every day (in person, ideally, about anything; I wouldn't count instant message or text chat here). I realise this may be hard if you live alone and work from home, but I would recommend it especially strongly in that case.
- Going out with friends once a week.
- Treating yourself to a tasty snack or meal out once a week. This is more optional than the rest. It's partly for the pleasure and partly to make it easier to eat healthy the rest of the time.
If you're not sleeping well, the resulting exhaustion can, by itself, make it hard to concentrate and get things done.
There are plenty of resources online addressing this, so I wouldn't go into too much detail on any of the recommendations nor try to provide an exhaustive list of recommendations.
Some things to try to do:
- Get 8 hours of sleep
- Go to bed well before midnight (combined with the above, this means: sleep when the sun's not shining)
- Go to bed and wake up at the same time every day (even on weekends)
- Don't snooze your alarms in the morning
- Sleep in a dark room (especially try to avoid lights from screens or LED's, which may include notifications you get at night on your phone)
- Avoid screens before bed or after it gets dark or install a blue light filter on your computer and phone like Flux or Twilight
- If you can't fall asleep after a while, get up and do something for a while - don't spend hours laying in bed awake
- Get lots of sunlight when you're awake (to help with your circadian rhythm, among other benefits)
- Avoid sleeping pills (unless prescribed by a doctor). Taking too many of these might make you dependent on them and make them less effective.
- Cut down on caffeine and sugar, especially in the afternoon and evening.
Relax, in healthy ways
Everyone needs to relax occasionally, so it's worth making a conscious effort to do things to relax and taking a sceptical look at anything you do to relax.
Although what any given person finds relaxing will vary greatly from one person to the next.
Exercising and socialising (especially doing sports, mentioned above) may be a sufficient source of relaxation for some, but it's not that relaxing for everyone.
If you have a hobby that's the same as your day job, you may need something other than this to truly relax.
If your day job requires a lot of complex problem solving, you may need to give your brain a break and not try to relax with something where you need to think a lot like Sudoku or chess.
Social media (including Stack Exchange and YouTube) is a topic all by itself. While I'd hesitate to say it's destructive to everyone, plenty of people quit social media because it has a negative effect on their mental health. They're optimised to keep you on the site as long as possible at any cost, not to be a good way to relax. So that's certainly something to keep in mind if you use this to relax, especially if you try to do so during a work day, have a hard time putting it down or don't feel all that satisfied afterwards.
Video games is something one can also say a lot about, and a lot of what I wrote about social media also applies to them. The free-to-play / mobile variety (which you can play for "just 5 minutes") are especially noteworthy, because they're optimised to keep you playing moment to moment, with daily rewards "forcing" you to come back and keep playing, potentially turning it into more of an obligation than a way to relax.
(Free-to-play) video games and social media both generally mess with dopamine production (your body's "feel good" drug). This could potentially have a long-term effect on how enjoyable you find anything.
Working from home might be a problem
When working from home, it can be hard to mentally separate work and play. Having where you work be in a different physical place can help with this.
If your employer doesn't have a physical office where you can work, you could also consider a coworking space. Or perhaps you have a room you can use exclusively for work.
You might also want to read through: How do you separate or integrate your work and home life when telecommuting?
Work reasonable hours
While not really applicable to you now, it may apply to others also suffering from similar symptoms.
Working more than 8 hours a day or not taking weekends off for extended periods of time may be one of the primary causes of burnout. One wouldn't really be able to fix burnout or mental fatigue if what's causing it is still there.
Follow a plan, routine or schedule
Our brains are (generally) good at doing this.
When you work from home, you may not have a well-defined start and end of the day. If you don't, I would recommend you define what time you start working, what time you take lunch, for how long and what time you stop working, and stick to this.
You could also set up a plan for what you'll achieve on some specific day and for how you structure your day.
If necessary, you could define how long you'll work before taking a break, what you'll do during that break and how long that break will be (set a timer for both). Many people swear by this to maximise their productivity.
Breaks should include avoiding screens altogether for at the very least 10 minutes every hour (for eye health, but also because things on electronic devices tend not to make for the best breaks - see also what I wrote about relaxing above), and regularly going outside.
When working normally, some recommend breaks after only about 30 minutes (and you may be surprised what you can get done in that time), while others might recommend working up to an hour. Recommended breaks are typically between 5 minutes (with longer breaks later on) and 30 minutes. One popular technique is the Pomodoro technique and there are a number of apps to make this easy. Another option would be to say you'll finish this one or two things before taking a break (as long as that won't take too long). I would recommend experimenting and further reading up on this to find the best solution for you.
To get back to being productive with mental fatigue or burnout, I might recommend tending towards shorter working periods and longer breaks, to give your brain more time to recover.
This also relates to some of the points above (especially working from home).
Getting constant alerts for instant messages or emails or having instant access to anything on your computer you usually use for relaxing could make it quite hard to focus.
Some options to consider:
Turn off notifications for phone apps, IMs and/or emails and only check these intermittently or at certain times of the day.
If you don't want to disable them completely, some apps may have notifications less invasive than a huge popup, like a change to the icon or title in the taskbar.
Your phone may also have some options to make some or all notifications less invasive, without disabling them completely (like disabling sounds or vibration or not even switching on the screen and only showing the notification light).
Install an app or browser extension to prevent opening certain apps or websites during certain hours.
- Uninstall certain apps altogether.
- Get a dedicated work computer (possibly sponsored by your employer). It would be much easier to avoid opening up some app if it's not even installed on the computer you're working on.
While certain medications might help or even be necessary to fix the problem, I would not recommend taking these without consulting a doctor first.
Medication carries serious risks: they may have serious side-effects, have a risk of overdosing, create a dependency on the drug, become less effective with overuse or cause damage in long-term. A doctor would help you minimise, deal with or avoid these risks.
Take on easier work tasks for a while
If there are tasks that need doing but don't require much concentration or time per task, you could consider focusing on these for a few days. Or at least for part of the day.
But do actually fully focus on these tasks like you would with "regular" work. Don't just do it for 5 minutes, get distracted and do something else, get back to it for 5 minutes, etc. That wouldn't help much.
This would allow you to get back into the spirit of working normally even if you can't really focus on anything. Once you're used to normal working hours again, focusing during that time should be much easier.
Give it time
Don't expect to immediately get back to 100% productivity. It may take a few weeks.
Take time off
You say this is not really an option, but I include it anyway for completeness and because it's one of the best ways to deal with mental fatigue (and you don't necessarily have to take a large amount of time off). Although one should still address any other potential contributors mentioned above.
Taking at least some time off away from home might be a lot more effective than just staying at home.
Even just taking a trip somewhere over a long weekend could help a lot.
I would especially recommend something that actually gets you excited to think about and something you'd typically really look forward to. Taking time off to be bored at home could do more harm than good.
Also, if you can currently only get one or two hours of productivity a day and taking a few days or a week off would fix your problem, that would definitely be worth it, even just from a purely financial perspective.
If applicable: I think debt is often harmful and ruins lives, but in this case I'd consider taking (or adding) a bit of debt so you can take time off now, because your mental health is one of the most important things in life and this could make financial sense even in the short term. But I would recommend a lot of care here and a very detailed plan of when you're going to pay it back.
See a doctor
If it isn't a financial burden, I would recommend regularly speaking to a therapist even if nothing is specifically wrong.
Although if work productivity is the only problem and it hasn't been a problem too long, I might not say it's specifically necessary. I would expect it to take some time for your brain to adjust after such significant shifts in how you spend your time. A few weeks is probably a bit long, but not if you haven't been doing much of the above.
If you need a doctor's note to take paid medical leave, you might want to go see a doctor anyway.
I should note there is no wonder drug to fix this. A (good) general practitioner or therapist would likely do some combination of recommending what I wrote above, although they may be more methodical about it, looking for other medical causes and supplementing treatment with medication to get results faster. A bad doctor might just prescribe sleeping pills and Adderall to deal with the problem in the short term without trying to address the cause or considering the long-term effects of those drugs.
How do you talk to your boss about it?
The first consideration would be the purpose of talking to them.
If they've probably seen your lack of productivity or raised concerns about it, this could be a decent way to address that. I'd probably recommend just keeping it simple:
- Say you've been having a hard time concentrating lately
- Give a reason (otherwise they may think it's because you dislike the job): you've overworked yourself on a personal project, which you've stopped doing now (but concentration is still a problem).
- Point out what they probably know already: the number of hours you've logged or anything else they may have noticed.
- Explain how you're addressing it: give a summary from the above points applicable to you, but avoid going into too much detail or anything that would be too personal. It would also be helpful if you can say you're seeing a doctor about it.
They may specifically ask about or recommend taking leave, so you should be prepared to answer that. I wouldn't get into your financial situation, but you can potentially say it's not the best time for you to take leave now and you plan to take some as soon as you're able.
If you want to take time off (medical or regular leave), it might also be useful to discuss it to justify the leave. Although it may not be necessary (you should not have to justify regular leave and a doctor's note should be sufficient for medical leave) and you should probably judge whether to do this based on how nice your boss is.
In other cases, I wouldn't discuss it unless you typical discuss personal matters with your boss.