Dual Diagnosis

For millions of people living with addiction, there’s a simultaneous conflict happening with their mental health. The research suggests that as many as half of all people with a substance use disorder (SUD) will also develop a drug addiction in their lifetime, and vice versa.

This pattern is what is clinically referred to as dual diagnosis. It underlines why recovery so often fails, when only one side of the problem is treated. Gaining clarity on how mental health and addiction interact might become your turning point when seeking treatment, helping you move beyond short-term relief and start the path towards sustained, complete recovery.

What exactly is “dual diagnosis” in recovery?

Dual diagnosis is a term used when someone is living with both a substance use disorder (SUD) and a mental health condition at the same time. Rather than living with the effects of both on their own, the two issues, more often than not, interact in ways that intensify one another. This makes recovery more complex if only one side is treated.

Millions of people around the world live with mental health issues that affect countless aspects of their lives. Conditions like anxiety, depression or trauma very often predate substance use, becoming ways to cope with deeply uncomfortable feelings. For others, prolonged substance use will trigger or worsen pre-existing mental health conditions, deeply altering their brain chemistry over time. Thus, we can see how either condition can fuel the development of the other.

What defines dual diagnosis is not simply the presence of two diagnoses, but the way the two are dangerously intertwined. Symptoms often overlap, mask one another or shift depending on which issue is worse at any given time. This is why dual diagnosis needs the most considerate and accurate assessments, followed by a treatment approach that addresses both conditions together, rather than in isolation.

Which mental health problems are most common in dual diagnosis?

Dual diagnosis can involve a wide range of mental health conditions, but some appear more frequently alongside substance use than others. The link between the more prevalent mental health conditions and SUDs cannot be mere coincidence. A person’s personal life, financial stability and Adverse Childhood Experiences (ACEs) can all make someone more vulnerable to developing an SUD or mental health condition. Some of the most common co-occurring mental health issues include:

• Anxiety disorders: Having anxiety that feels like it never goes away can drive people towards drugs as a way to calm themselves, often worsening the symptoms over time.
• Depression: Persistent low mood and hopelessness can fuel substance use as a form of escape, while drugs and alcohol often extend depressive cycles.
• Bipolar disorder: Drugs are sometimes used to heighten manic states or dampen depressive lows, which destabilises mood regulation.
• Personality disorders: Difficulties with emotional regulation, impulse control and relationships can increase vulnerability to addictive behaviours.
• PTSD and trauma-related disorders: Those struggling with PTSD and trauma might use drugs to suppress intrusive thoughts and emotional distress, which reinforces avoidance patterns and dependence.

The substances most frequently found in dual diagnosis

As we’ve listed some of the most commonly recurring mental health issues, research also shows us how some substances are more common than others in dual diagnosis. These substances include:

• Alcohol: Alcohol, being the most readily available substance, is involved in most dual diagnosis cases. Excessive drinking will make depression worse and cause greater emotional instability in the long term.
• Marijuana: Cannabis is another substance observed in dual diagnosis treatment, with research indicating its increasing use amongst young people. Marijuana addiction is linked with anxiety and mood disorders, especially when used to manage stress.
• Cocaine: cocaine addiction is often associated with underlying depression, bipolar disorder or low self-worth. Stimulant highs mask emotional pain before intensifying crashes.
• Opioids: Opioid addiction is commonly connected to trauma and PTSD, where numbing effects provide temporary relief but eventually make life worse.

What makes identifying and treating dual diagnosis difficult?

In a sense, identifying dual diagnosis is comparable to looking into a two-way mirror. What first appears to be a single condition can actually be the reflection of another working alongside it. For many people, drug addiction forms after looking for a way to cope with psychological distress. Over time, however, that coping mechanism can deepen mental health symptoms or introduce entirely new ones.

This overlap can make dual diagnosis difficult to identify and treat. Research indicates that as many as one-third of all people receiving treatment for mental health also meet the criteria for a substance use disorder. When the focus shifts in the opposite direction, the numbers can be just as high. Estimates from the NHS Addictions Provider Alliance indicate that over 80% of people entering treatment for alcohol misuse report a co-existing mental health problem.

Determining which came first, or which one is currently posing a greater threat, is rarely straightforward. Mental health symptoms and drug addiction effects often coincide, making a clear diagnosis more complex.

Many warning signs appear in both conditions. Anxiety, disrupted sleep, low mood, fatigue and emotional instability can stem from mental illness, substance use, or both. When only one side is treated, the other may continue unchecked, undermining recovery.

For this reason, long-term progress often depends on recognising and treating both conditions together, rather than attempting to separate them.

Dual diagnosis treatment: the critical role of integrated care

Dual diagnosis treatment is most effective when both mental health conditions and substance use disorders are addressed together, rather than treated as separate issues. This approach is known as integrated care, and it has become the most effective method for treating those who receive a dual diagnosis.

Research published in Psychiatric Clinics of North America highlights that people with co-occurring disorders experience better outcomes when both conditions are treated simultaneously by a coordinated clinical team, rather than through parallel services. When mental health symptoms are treated in isolation, substance use often remains unaddressed, and vice versa, increasing the risk of relapse in early recovery.

Integrated care helps clinicians understand how each condition influences the other. By using an integrated care approach, neither condition is overlooked and overlapping symptoms are given effective treatment.

For people receiving dual diagnosis treatment, recovery becomes much more likely when therapy, medical care and relapse prevention are aligned to both conditions.

Where can I find out more about dual diagnosis treatment?

If you or someone you care about is struggling with both mental health challenges and substance use, it’s important to know that support exists that treats both conditions together.

At Banbury Lodge, we specialise in dual diagnosis treatment that recognises how closely addiction and mental health are connected. Our clinical team is experienced in integrated care, which combines medical detox, psychiatric support and evidence-based therapy within a coordinated treatment plan. Our approach means neither condition is left in isolation, guiding you towards lasting and complete recovery.

If you’re ready for the next step, our team is waiting to listen, support and then guide you towards the healthier, sober future you deserve.