My family and friends find me unbearable. Is that bad?

It is normal and temporary. Tell them it is the withdrawal, take a break when you feel irritability rising, and apologise when you snap — without beating yourself up.

I am angry at everyone, is that a sign I should start smoking again?

No — it is precisely the sign that your brain is switching to the non-smoker state. Holding on for 2-3 more weeks means getting past the peak.

Is brain fog dangerous for my job?

Be careful if your job demands extreme focus (surgeon, driver, etc.). Avoid major decisions for the first 2 weeks, or take a few days off.

How long before my mood is better than before?

2 to 3 months for most ex-smokers. It is a major and little-known benefit of quitting.

Mood, irritability and brain fog after quitting smoking: how long does it last

Irritable, low, unable to focus since you quit? Here is the precise timeline of psychological withdrawal symptoms and when to see a doctor.

July 8, 2026 Aria

The scientific basis on quitting smoking was reviewed on a voluntary basis by Pr. Bertrand Dautzenberg , a tobacco specialist, in order to rule out gross, potentially dangerous errors. It reflects positions commonly shared by health professionals and health agencies, without always corresponding exactly to his thinking or his practice. He is not the author of this text; he has only carried out a vigilance review of it.

You quit a few days ago. You snap at everything, you cry over an out-of-date yogurt, you cannot finish a sentence at work. Your brain runs in slow motion. You wonder: is it me, or is it the withdrawal?

The answer: it is the withdrawal. And yes, it is time-limited. Here is what you can expect, day by day.

Why your brain is losing it

Nicotine acts in your brain as a modulator of several neurotransmitters: dopamine (pleasure), noradrenaline (alertness), acetylcholine (focus), GABA (calm), serotonin (mood).

When you smoked, your brain got used to a regular intake (every 30 to 60 minutes). Without a cigarette, it is now rebalancing the whole thing without its main crutch.

During this transition, it is normal to feel:

60-80% of people who quit report at least 3 of these symptoms during the first week.

DSM-5 and clinical studies on the withdrawal syndrome

The timeline, day by day

Day 1-2 a few smokers have a surprisingly OK 'honeymoon'. Most feel irritability rising from day 1.
Day 3-5 peak symptoms. Irritability at its max, anxiety, sometimes tears for nothing.
Day 6-10 physical symptoms fade, mental symptoms stay on a rollercoaster.
Week 2-3 clear easing, but still some rough moments.
Week 4 most people feel broadly 'normal' again.
Month 2-3 mood better than before quitting for most ex-smokers.

Tobacco withdrawal classically includes: irritability/anger, anxiety, difficulty concentrating, increased appetite, restlessness, depressed mood, insomnia. These symptoms appear within 24 hours of cutting down or stopping and usually last several weeks.

DSM-5, American Psychiatric Association

Brain fog, that weird thing

This is probably the most disorienting one. You feel slow, as if your brain is walking through treacle:

you cannot find your words,
you forget why you walked into a room,
you read an email 3 times without catching the meaning,
you make simple mistakes at work.

This 'fog' typically lasts 2 to 4 weeks. It is due to the readjustment of acetylcholine and the gradual release of dopamine without its artificial booster.

How to get through this stretch

Hydration and sleep

not glamorous, but it really helps. 7-8 hours of sleep, 1.5 L of water a day.
Physical activity

20-30 minutes a day, even walking. Exercise releases endorphins that partly make up for the lost dopamine.
Nicotine substitutes

at a sufficient dose. A lot of irritability comes from underdosing. If you have too much craving, step up.
Caffeine

consider halving your intake during the first weeks. Tobacco speeds up its metabolism — without tobacco, your usual dose can make you anxious.
Warn your circle

'I am going to be a pain for 2-3 weeks, it is the withdrawal, do not take it personally.'

When to see a doctor

Withdrawal disturbs mood, but should not create lasting distress. See a doctor if:

The bonus to expect

After 1-2 months, most ex-smokers find:

In United Kingdom

Your questions

My family and friends find me unbearable. Is that bad?

It is normal and temporary. Tell them it is the withdrawal, take a break when you feel irritability rising, and apologise when you snap — without beating yourself up.
I am angry at everyone, is that a sign I should start smoking again?

No — it is precisely the sign that your brain is switching to the non-smoker state. Holding on for 2-3 more weeks means getting past the peak.
Is brain fog dangerous for my job?

Be careful if your job demands extreme focus (surgeon, driver, etc.). Avoid major decisions for the first 2 weeks, or take a few days off.
How long before my mood is better than before?

2 to 3 months for most ex-smokers. It is a major and little-known benefit of quitting.

sources

American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders (DSM-5), criteria for tobacco withdrawal syndrome.
Hughes JR, Effects of abstinence from tobacco: valid symptoms and time course, Nicotine Tob Res, 2007.
Taylor G, McNeill A et al., Change in mental health after smoking cessation: systematic review and meta-analysis, BMJ, 2014.
CDC, Common Withdrawal Symptoms, updated 2024.