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Alcohol and substance use

People with untreated ADHD are statistically more likely to develop substance use problems, especially involving alcohol, cannabis, or stimulants.

ADHD involves dopamine dysregulation — people may use substances to self-medicate for low motivation, restlessness, or emotional distress.

This is not a personal failure. ADHD affects the parts of your brain that are linked to reward, impulse control and emotional regulation, which can increase your vulnerability to substance misuse.

Alcohol

You have to be aged 18 or older to legally purchase alcohol.

Drinking alcohol has different effects, including relaxation, lowered inhibitions and impaired judgement. It can make ADHD symptoms worse resulting in poor attention, poor organisation, poor mood and poor sleep the next day.

There are risks of addiction, liver disease, heart issues, mental health impact.

Do not regularly drink more than 14 units of alcohol per week.
Spread drinking over three or more days if you drink as much as 14 units a week.
Have several alcohol-free days each week.
The 14-unit limit applies equally to men and women.

Find out more about the number of units in different drinks

Beer (4%) ~2 pints = 8 units.

Wine (13%) ~2 large (250ml) glasses = 6 units

Cider (5.5%) ~2 pints = 11 units

Spirits (40%) ~7 single (25ml) shots = 9 units

Caffeine misuse or dependence

Caffeine misuse happens when consumption exceeds safe levels or causes harm to health, mood, or behaviour.

It may lead to dependence — where a person feels unable to function normally without caffeine.

Signs of caffeine misuse:

Consuming large amounts daily (often >600 mg)
Feeling jittery, anxious, or restless
Sleep problems or insomnia
Headaches or stomach upset
Needing more caffeine for the same effect (tolerance)
Withdrawal symptoms (headache, fatigue, irritability) if intake stops suddenly

Illegal and controlled substances

It’s essential to realise that recreational drugs are illegal.

Cannabis

Some people report feeling calmer or less restless, however evidence does not support cannabis as an effective treatment for ADHD.
Regular use of cannabis can worsen memory, motivation, and concentration, which may increase ADHD‑related difficulties.

Stimulants and other drugs

Illicit stimulants (for example cocaine or amphetamines) may briefly improve focus but they significantly increase the risks of dependence, anxiety, mood problems, and physical harm.
ADHD combined with stimulant misuse is associated with poorer mental health outcomes.

If you are struggling with ADHD symptoms you are not alone.
Help is available and seeking support will not disadvantage your ADHD assessment or treatment. Addressing both together leads to better outcomes. Please see details below.

Things you can do

Seek support from family and friends and have open conversations. And use ADHD friendly coping strategies, like those below.

Reduce harm (even if stopping feels hard) by spacing out use, avoiding mixing substances and planning alcohol free or substance free days.
Keep hydrated, eat regularly, and protect your sleep routine where possible.
Notice patterns and gently track when you use substances and what was happening beforehand (stress, boredom, overwhelm, poor sleep) as this can help you and professionals understand what support you may need.
Create short, structured routines.
Use movement or exercise to manage restlessness
Set external reminders (alarms, notes, phone apps)
Break tasks into very small steps