What is dual diagnosis treatment, and why does it matter?

In this article

1. What is dual diagnosis?
2. What are the risk factors for dual diagnosis?
3. Which mental illnesses are linked to addiction?
4. Which drugs can trigger a mental disorder?
5. Why is dual diagnosis assessment and treatment important?
6. What are the signs and symptoms of dual diagnosis?
7. How is dual diagnosis treated?
8. Questions people ask

In a study of 250 inpatients treated for alcohol, cocaine or heroin dependence, those with major depression during abstinence relapsed at about three times the rate of the others (Hasin and colleagues, 2002). In South Africa, 17% of people admitted to specialist treatment in the second half of 2025 arrived with a dual diagnosis, up from 15% earlier that year (SACENDU). Renewed Life Center in Lakeside, Cape Town, treats both on one plan.

What is dual diagnosis?

Dual diagnosis means a substance use disorder and a mental health condition in the same person at the same time: alcohol dependence with depression, tik with psychosis, cocaine with ADHD. Clinicians also call it co-occurring disorders or comorbidity. Each makes the other worse and harder to treat.

In England, 74% of adults starting drug and alcohol treatment in 2024 to 2025 reported a mental health treatment need, government statistics show.

2023 to 202472%

2024 to 202574%

Which comes first, the addiction or the mental health condition?

Either can come first, NIDA explains:

• shared risks such as trauma and stress can lead to both;
• anxiety or depression can lead to drinking for relief;
• substance use can bring on a condition a person was already prone to.

Heavy drinking can itself cause low mood that lifts once the person stops, which is why NICE guideline CG115 advises assessing depression or anxiety that “continues after 3 to 4 weeks of abstinence from alcohol”.

What are the risk factors for dual diagnosis?

The main risk factors for dual diagnosis are genes, brain chemistry and the environment, especially chronic stress and childhood trauma.

Genetics

Genes account for between 40 and 60 percent of a person’s risk of addiction, NIDA estimates. A parent or sibling with addiction, depression or bipolar disorder tells the team where to look.

Brain chemistry

Substance use changes the circuits for reward, impulse control and mood, the same ones disrupted in depression and anxiety. That is why early sobriety can feel flat or restless for weeks.

Environment: stress and childhood trauma

In the ACE Study of 9,508 adults, those with four or more kinds of childhood adversity had a 4- to 12-fold higher risk of alcoholism, drug abuse, depression and suicide attempts (Felitti and colleagues, 1998). Stop the drink without touching that root, and the root is still there when the cravings come.

At Renewed Life Center both conditions are assessed from the first days and go into one plan. Ruby Weber, who heads psychology here, is particularly interested in how trauma feeds an addiction, and the WHO and UNODC International Standards (2020) ask for the same screening for “comorbid mental disorders”.

Which mental illnesses are linked to addiction?

The mental illnesses most often linked to addiction are:

• anxiety disorders, often eased by alcohol or benzodiazepines (see anxiety and depression support);
• depression and bipolar disorder;
• personality disorders, borderline above all;
• PTSD, where substances dull flashbacks and nightmares (see trauma and PTSD recovery);
• ADHD, found in 23% of people with a substance use disorder in a 2012 meta-analysis.

Which drugs can trigger a mental disorder?

Alcohol, cannabis (dagga), cocaine, methamphetamine (tik) and benzodiazepines have the clearest links to depression, anxiety, paranoia and psychosis. Heroin is sold in South Africa as nyaope or whoonga, often mixed with other substances, SACENDU notes, and depression and anxiety are common alongside it.

Anyone who drinks every day or takes benzos, mandrax or opioids should not stop suddenly on their own: message us first, and we will tell you whether a medical detox is needed and arrange it.

Why is dual diagnosis assessment and treatment important?

Dual diagnosis assessment matters because the condition nobody finds is the one that brings the person back. The drink or the drug was quietening anxiety, low mood or trauma symptoms. When those return a few weeks into sobriety and the plan covers only cravings, a drink is the quickest relief.

“Take the substance away without treating what sits underneath, and the symptoms return.”

What are the signs and symptoms of dual diagnosis?

The signs of dual diagnosis are mood, sleep and behaviour changes that get worse after drinking or using, and relapses that follow a feeling rather than a party. Common signs include:

• low mood, hopelessness or loss of interest;
• anxiety or panic eased only by a drink or a pill;
• paranoia, hallucinations or sharp mood swings;
• pulling away from family and friends;
• self-harm or talk of suicide.

Call 10177 for an ambulance, or 112 from any cellphone, if someone is talking about ending their life or has tried to; is having a seizure; is confused or hallucinating after stopping alcohol or sedatives; or is unresponsive or breathing slowly after using drugs. The Suicide Crisis Helpline is 0800 567 567, day or night.

At home it looks like a husband who is fine on Monday and gone by Thursday. If that is your family, write to us and tell us what you have seen.

How is dual diagnosis treated?

Dual diagnosis is treated with integrated care: one team assesses both conditions, writes one plan and treats both during the same stay. Treating both at once “can make all the treatments more effective”, NIDA reports, and SAMHSA’s guide puts safety and detox first, then therapy for the underlying condition.

We use CBT for the thoughts behind a drink or a panic attack, DBT for intense emotion and cravings, schema therapy for old patterns, EMDR and TRE for trauma, family therapy, and relapse prevention that covers low mood as well as cravings. NICE recommends CBT for alcohol dependence, and NICE and the WHO recommend EMDR for PTSD.

How does Renewed Life Center treat dual diagnosis?

Renewed Life Center, a private residential rehab in Lakeside, Cape Town, treats addiction and mental health in one house, on one plan.

Ruby Weber has worked in addiction for more than twenty years and has held clinical directorships at rehabilitation clinics in South Africa. Around her are Dr John Wulz, our GP, who sees every client; Leila Bolland, social worker and therapist since 2015; Nikki Edwards, Programme Director and Clinical Manager, with 11 years in recovery; and John Roberts, Senior Recovery Specialist, with 39 years in recovery. A psychiatrist selects medication where needed, and medical detox happens on site with 24-hour nursing supervision.

Treatment runs in one-month phases, with individual therapy typically three times a week in the first month, when you live at the centre and get safe and steady; the second month goes to what the drinking or using was covering. NIDA calls an adequate length of treatment critical, so we plan in months. More on our dual diagnosis treatment in Cape Town.

Our family group meets on Zoom every Wednesday at 18:00. If your family member is not ready yet, read how to talk to a loved one about going to rehab. The first call is free, and admission usually follows within three days.

Questions people ask

Sources

1. SAMRC, SACENDU Research Update, July to December 2025; OHID treatment statistics 2024 to 2025
2. Hasin and colleagues, Archives of General Psychiatry, 2002; Felitti and colleagues, ACE Study, 1998
3. NIDA: co-occurring disorders; Drugs, Brains, and Behavior; Principles of Drug Addiction Treatment
4. van Emmerik-van Oortmerssen and colleagues, ADHD in substance use disorder, 2012
5. WHO and UNODC International Standards, 2020; SAMHSA TIP 42; NICE CG115 and NG116

This article is general information, not medical advice.