Bad Sleep, Short Temper, Flat Mood: The First Two Weeks

Almost nobody warns you that quitting can wreck your sleep and turn you into someone unpleasant to live with. It is normal, it is temporary, and one very ordinary thing is often making it worse.

Somewhere around day four, a lot of people arrive at the same private conclusion.

I am not enjoying anything. I cannot sleep. I snapped at someone who did not deserve it. Maybe the smoking was actually holding something together.

It is a convincing thought, arriving at the worst possible time, and it ends a lot of quit attempts.

Here is what is actually happening, how long each part lasts, what makes it worse, and the point at which it stops being ordinary withdrawal and becomes something to take to a doctor.

These are symptoms, and they are on the official list

This is not you failing to cope. Every one of these is a recognised nicotine withdrawal symptom.

The National Cancer Institute lists them: "nicotine cravings, anger, frustration, and irritability, difficulty concentrating, insomnia, restlessness, anxiety, depression, hunger or increased appetite."

Insomnia is on that list. So are anger and depression. If you are irritable and not sleeping, you are not reacting badly to quitting - you are experiencing the documented, expected course of it.

The timings, which are the useful part

Vague reassurance does not help at 3am. Specific timings do.

The overall shape. The NCI: withdrawal symptoms are "usually worst during the first week after quitting, peaking during the first 3 days." The NHS puts average duration at around three to four weeks.

Low mood. The NCI is precise: "If mild depression occurs, it will usually begin within the first day, continue for a couple of weeks, and go away within a month."

Anxiety. "If anxiety occurs, it usually builds over the first 3 days after quitting and may last several weeks."

Notice that anxiety builds over three days. It does not start at maximum. This is why day three catches people who thought they had got away with it.

Sleep. Sleep tends to be worst in the first week or two and settles as the rest of the withdrawal does. Many people end up sleeping better than they did as smokers, once it settles.

Low mood: usually gone within a month. Anxiety: several weeks. The worst single stretch: the first three days. None of these are the rest of your life.

The thing that is quietly making it worse: your coffee

This is the single most useful and least known fact in this article.

Smoking speeds up how fast your body clears caffeine. Compounds in tobacco smoke induce a liver enzyme, CYP1A2, which is the main enzyme that metabolises caffeine.

As one clinical review puts it: "smokers require three to four times the caffeine doses compared to non-smokers to get similar plasma caffeine levels."

Now stop smoking. The induction fades over a period of weeks. Your caffeine clearance slows down. And your four coffees a day - the number you settled on as a smoker - start producing substantially higher caffeine levels than they used to.

Which means, in week one, on top of nicotine withdrawal, a lot of people are also mildly over-caffeinated. And the symptoms of too much caffeine are: anxiety, jitteriness, irritability, a racing heart, and not being able to sleep.

That is the same list as the withdrawal. It stacks on top.

Practical things for the sleep specifically

Sleep is where people suffer most quietly, because being awake at 3am is where the case for going back to smoking sounds most reasonable.

Nicotine patches at night. If you use a 24-hour patch and your sleep is disrupted or you are having vivid or unpleasant dreams, this is a known issue and it has a simple answer: some people do better taking the patch off at bedtime and putting a fresh one on first thing. That is a conversation for a pharmacist, not a decision to make alone, because it also means waking up with less nicotine on board - which for some people makes the morning harder. Worth five minutes of a pharmacist's time.

The caffeine cut-off, as above. This is the biggest lever.

Do not chase the sleep. Lying in bed calculating how many hours are left makes it worse. If you are awake for more than about twenty minutes, get up, go somewhere dim, do something boring, go back when you feel sleepy.

Expect vivid dreams. They are common in early cessation and they surprise people. They are not a sign of anything wrong.

Accept a bad fortnight. Genuinely - if you can arrange it, do not quit in the same week as a major deadline. Some sleep is going to be lost. Planning for it is better than being blindsided by it.

The mood, and the belief that comes with it

Here is where the reasoning gets dangerous, because it is internally consistent.

I feel worse since I quit. Smoking must have been helping. Therefore going back will fix it.

Every step follows. And going back does fix it, immediately, which appears to prove the whole chain.

What it actually proves is narrower: smoking relieves nicotine withdrawal. That is all it demonstrates. The reason smoking feels like it fixes your mood is that your mood was disturbed by the absence of nicotine in the first place. There is a whole article on this site about that loop.

What the longer-term evidence shows is the opposite of the intuition. A 2014 meta-analysis in the BMJ by Taylor and colleagues compared people who quit with people who kept smoking, and found quitting associated with decreased anxiety, decreased depression and decreased stress, plus increased positive mood and better psychological quality of life.

The NHS gives the timescale: "It can take as little as 6 weeks to start feeling the mental health benefits."

Six weeks. The bad patch is two to four. So there is a gap - a period where you feel worse and the improvement has not arrived - and that gap is where most people give up, weeks before the thing they wanted would have shown up.

The first fortnight is not what being a non-smoker feels like. It is what withdrawal feels like. Almost nobody stays long enough to tell the difference.

When it is not just withdrawal

Everything above describes the ordinary course. It does not describe everyone, and this section matters more than the rest of the article.

Talk to a doctor if:

Low mood is severe, rather than flat and grey
It is not lifting after about a month, which is outside the pattern the NCI describes
You have a history of depression, anxiety or other mental health conditions. This is worth raising before you quit, not after. Quitting is still very much worth doing - the evidence above applies - but it is worth doing with someone keeping an eye on it.
You are having thoughts of harming yourself. Do not wait to see whether it passes. Contact a doctor or a local crisis line now.
Sleep is badly disrupted beyond a few weeks

And one specific thing that is easy to miss: if you take regular medication, tell your doctor or pharmacist that you are stopping smoking.

The same enzyme effect that changes how you handle caffeine also affects some medicines. Blood levels of certain drugs - clozapine and olanzapine are the commonly cited examples - are affected by smoking, and stopping can change how much of the drug is in your system. That is a dose conversation, and it is one your prescriber needs to be part of.

It is a two-minute mention at a pharmacy counter and it is genuinely important.

What to hold on to for fourteen days

The nicotine itself is gone within 24 hours. Everything after that is adjustment.
Day three is the peak. It gets better from there, unevenly.
Low mood usually resolves within a month. Anxiety, within several weeks.
Cut the caffeine. It is doing more than you think.
Reaching 28 days smoke free is associated with being five times more likely to stay quit for good.
Feeling worse now is not evidence that smoking was helping. It is evidence that you have stopped.

Frequently Asked Questions

Is insomnia normal after quitting smoking?

Yes. The National Cancer Institute lists insomnia among the common nicotine withdrawal symptoms, alongside irritability, anxiety, difficulty concentrating and low mood. Sleep disruption is usually worst in the first week or two and settles as the rest of the withdrawal does.

How long does low mood last after quitting smoking?

According to the National Cancer Institute, if mild depression occurs it usually begins within the first day, continues for a couple of weeks and goes away within a month. Anxiety typically builds over the first three days and may last several weeks. Severe or persistent low mood is a reason to speak to a doctor.

Why am I more anxious and sleeping worse since I quit, if quitting is supposed to help my mental health?

Withdrawal comes first and the benefits come later. A 2014 BMJ meta-analysis found quitting was associated with decreased anxiety, depression and stress compared with continuing to smoke, and the NHS says it can take as little as six weeks to start feeling the mental health benefits - which is after the two to four weeks when withdrawal is at its worst.

Should I drink less coffee when I quit smoking?

Often, yes. Smoking speeds up caffeine metabolism, and clinical reviews note that smokers need three to four times the caffeine dose of non-smokers to reach similar blood levels. When you stop smoking, that effect fades over several weeks and your usual coffee intake can produce noticeably higher caffeine levels, adding jitteriness, anxiety and insomnia on top of withdrawal.