UK addiction guides by substance
Signs, withdrawal timelines, detection windows and UK treatment routes — plain English, no scare tactics.
Dissociative anaesthetic
Ketamine
Ketamine is a dissociative anaesthetic used medically and, at higher recreational doses, taken for its detached, floaty effects. UK use has climbed sharply since 2023, and daily users often develop bladder damage, cramping stomach pain ("K-cramps") and psychological dependence long before they think of themselves as addicted.
Depressant
Alcohol
Alcohol is the UK's most common addiction and, alongside benzodiazepines, one of the few withdrawals that can kill without medical supervision. Daily drinkers who feel shaky, sweaty or anxious in the morning almost always need medically-supported detox, not willpower.
Stimulant
Cocaine
Cocaine is the most common illegal drug driving UK private-rehab admissions. It rarely causes classic physical withdrawal, but the mood crash, cravings and knock-on damage to relationships, work and finances are what typically bring people to treatment.
Gabapentinoid
Pregabalin
Pregabalin is prescribed for nerve pain and anxiety. It's now one of the fastest-growing prescription-drug dependencies in the UK, and withdrawal can be severe: rebound anxiety, insomnia, sweating and, in some cases, seizures. Stopping suddenly is unsafe.
Z-drug (benzodiazepine-like sleeping pill)
Zopiclone
Zopiclone is a short-term sleeping pill that's routinely used for years despite being licensed for 2–4 weeks. Dependence looks like insomnia, morning anxiety and needing higher doses to sleep. Withdrawal is best managed with a slow taper under medical supervision.
Cannabinoid
Cannabis
Modern UK cannabis is dominated by high-THC skunk, which is far more addictive than the plant of 20 years ago. Daily use commonly drives low mood, anxiety, loss of motivation and, in vulnerable users, psychosis. Withdrawal is real: sleep disruption, irritability, sweats and cravings peak in the first two weeks.
Opioid
Heroin
Heroin remains the drug most associated with UK overdose deaths, and the arrival of nitazenes in the UK supply from 2023 has made overdose risk sharply higher. Physical dependence develops within weeks; withdrawal is intensely uncomfortable but rarely dangerous.
Benzodiazepine
Diazepam
Diazepam is the most-prescribed UK benzodiazepine and — alongside alcohol — one of the only withdrawals that can kill without medical supervision. Long-term users develop tolerance, dose creep, and severe rebound anxiety. Never stop abruptly.
Opioid
Codeine
Codeine is Britain's most common over-the-counter opioid dependence. Products like Nurofen Plus, Solpadeine and co-codamol are widely available and easy to escalate on. Long-term use adds paracetamol or ibuprofen overdose to the opioid problem.
Opioid (atypical)
Tramadol
Tramadol is an atypical opioid that also affects serotonin and noradrenaline. That gives it a nastier withdrawal than pure opioids — panic, mood crashes, and seizure risk on top of standard opioid symptoms. It is a UK Class C controlled drug.
Gabapentinoid
Gabapentin
Gabapentin is a nerve-pain and epilepsy medication. Alongside pregabalin, it's one of the fastest-growing prescription-drug dependencies in the UK, particularly among people who also use opioids. Withdrawal mirrors pregabalin: rebound anxiety, sweats, insomnia and, in heavy users, seizure risk.
Benzodiazepine
Xanax
Xanax (alprazolam) is not routinely prescribed in the UK, but is widely bought online — often counterfeit, sometimes containing nitazenes or novel benzos. It's short-acting, powerful, and produces one of the fastest, most severe benzodiazepine dependencies.
Empathogen / stimulant
MDMA
MDMA is not classically physically addictive, but heavy weekend use and rising pill/crystal strength in the UK cause serious problems: mid-week mood crashes, worsening anxiety, and — in vulnerable users — persistent low mood and derealisation.
Dissociative gas
Nitrous oxide
Nitrous oxide became a Class C drug in the UK in November 2023. Heavy use — especially large canisters — causes vitamin B12 inactivation and can lead to serious, sometimes permanent, nerve damage (subacute combined degeneration of the spinal cord).