Mental health & dual-diagnosis guides
Addiction rarely travels alone. These guides cover the conditions we most often see alongside substance use in the UK, and how integrated treatment works.
Dual diagnosis is the UK term for having both an addiction and a mental-health condition — most commonly depression, anxiety, PTSD, bipolar or a personality disorder. Around 70% of people in UK addiction treatment meet criteria for at least one co-occurring condition.
Depression and addiction feed each other. Alcohol, cocaine, cannabis and prescription opioids all worsen depression over time — but they numb it short-term, which is exactly why so many people use them. Treating one without the other rarely holds.
Anxiety is the single most common reason people give for daily drinking, cannabis use or benzodiazepine dependence. The substances calm the anxiety in the moment and dramatically worsen it between doses — the loop that traps most people.
Untreated trauma is at the root of most severe addiction cases in the UK. Alcohol, opioids, ketamine and cannabis all numb intrusive memories, nightmares and hypervigilance — until they stop working. Treating one without the other rarely holds.
Borderline personality disorder (called EUPD in the NHS) and addiction commonly co-occur. Impulsivity, emotional intensity and self-harm risk make standard rehab hard to hold — treatment needs to be DBT-informed and long enough to matter.
Adults with untreated ADHD are 3–5× more likely to develop addiction. Cocaine, amphetamines and cannabis all self-medicate the underrepresented dopamine — the substances 'work' until tolerance and consequences catch up. Diagnosis and treatment change the picture.
Eating disorders and addiction share brain systems and often trade places over a lifetime. Bulimia and binge-eating disorder co-occur with alcohol and stimulant addiction most often. Both need specialist treatment — a rehab that only knows addiction can make an eating disorder worse.
Around 60% of people with bipolar disorder experience addiction at some point — the highest rate of any mental-health condition. Alcohol, cocaine and cannabis are the most common. Stopping any of them without stable mood treatment risks a manic or depressive episode.
OCD is often missed alongside addiction. Alcohol and cannabis quiet intrusive thoughts short-term; stopping them without OCD treatment usually causes a symptom flare. The evidence-based OCD treatment (ERP therapy) works alongside recovery — most people need both.