COMHAD: Understanding Co-Occurring Mental Health, Alcohol and Drugs (previously: Dual Diagnosis)

Cheshire Sobriety Clinic
Sep 19
6 min read

Updated: Nov 4

John & Dr Shyra — Also known as: Co-occurring substance use and mental health disorders (CoSUM)

Dual diagnosis, or co-occurring disorders refers to the presence of concurrent mental health difficulties and substance misuse in the same person. This combination presents particular risks and complications, but recent research has highlighted just how widespread it is, what underlies it, and how services are evolving to respond. In this article, we’ll unpack the latest evidence (2022-2025), explore why dual diagnosis is so hard to treat, and show how integrated, compassionate care can make a difference.

In recent years, professionals have moved away from simply calling it “dual diagnosis.” Increasingly, the term COMHAD short for Co-occurring Mental Health, Alcohol and Drugs is used to describe people who experience both substance use difficulties and mental health problems at the same time. COMHAD better reflects the complexity of the issue, acknowledging that alcohol, drugs, and mental illness rarely exist in isolation.

This blog explores what COMHAD means, why it’s such a pressing issue, the risks people face, and how integrated care, like that offered at Cheshire Sobriety Clinic can make recovery possible. Our founder John Wilkinson is also a COMHAD (Dual Diagnosis) Practitioner in NHS mental health service.

What Is COMHAD?

The term COMHAD is used by the Office for Health Improvement and Disparities (OHID, 2025) and the Royal College of Psychiatrists (2025) to highlight the reality that most people in substance misuse treatment also have mental health needs. Unlike the older “dual diagnosis,” COMHAD reflects the fact that individuals often face multiple difficulties simultaneously:

Alcohol misuse combined with depression or anxiety.
Opiate dependence alongside psychosis.
Polysubstance use connected with post-traumatic stress disorder (PTSD).

Using COMHAD helps services design more integrated responses, breaking down the unhelpful separation between “addiction services” and “mental health services.”

How Common Is COMHAD?

COMHAD is widespread. According to the latest UK figures, 72% of adults starting substance misuse treatment in 2023–2024 also had a co-occurring mental health treatment need (GOV.UK, 2024). This represents a significant rise from 53% in 2018–2019. The OHID COMHAD profile (2025) confirms that people with both alcohol/drug misuse and mental illness face much higher rates of hospital admission, self-harm, and mortality than those with either issue alone.

International research echoes this. In the U.S., adults with substance use disorders were far more likely to report depression or anxiety, yet only 14.4% accessed treatment in the past year (Katz et al., 2025). Studies of people with opioid use disorder show that up to 60% also have another SUD and more than 70% report a lifetime of polysubstance misuse, clear evidence of overlapping complexity (Santucci et al., 2024).

Why Do COMHAD Conditions Occur Together?

Researchers highlight several reasons why COMHAD is so common:

Shared Risk Factors – Early trauma, adverse childhood experiences, and social deprivation increase vulnerability to both substance misuse and mental health problems (Stringer et al., 2023).
Biological Links – Genetic studies reveal shared markers that increase susceptibility to both substance misuse and psychiatric disorders, particularly in relation to dopamine regulation (NIH/NIMH, 2023).
Coping Mechanisms – Many people use alcohol or drugs to self-medicate symptoms of anxiety, depression, or psychosis, creating a cycle of dependence (Leung et al., 2023).
Social Exclusion – Poverty, homelessness, and unemployment heighten the risk of both conditions and make accessing help harder (Stringer et al., 2023).

The Risks of COMHAD

Living with COMHAD carries serious risks, many of which are more severe than when conditions occur alone.

Poor physical health: Higher rates of liver disease, HIV, and cardiovascular illness are common (Santucci et al., 2024).
Increased psychiatric instability: Alcohol and drugs often worsen underlying symptoms. For example, cannabis use in schizophrenia increases relapse risk (Royal College of Psychiatrists, 2025).
Elevated suicide risk: People with COMHAD are at significantly greater risk of suicide and premature mortality (Royal College of Psychiatrists, 2025).
Poorer treatment outcomes: A Sydney cohort found that dual diagnosis patients were more likely to relapse, disengage from treatment, or need multiple hospital admissions (Leung et al., 2023).
Wider social harms: COMHAD is strongly linked with homelessness, unemployment, and criminal justice involvement (OHID, 2025).

Barriers to Treating COMHAD

Despite the scale of COMHAD, treatment remains fragmented. Barriers include:

Split services – Addiction and mental health services often work separately, leaving clients excluded if they don’t meet narrow eligibility thresholds (Royal College of Psychiatrists, 2025).
Diagnostic overshadowing – Substance misuse can obscure psychiatric symptoms, or vice versa, delaying accurate diagnosis (Leung et al., 2023).
Stigma – People with COMHAD face a “double stigma,” discouraging them from seeking help (Katz et al., 2025).
Socioeconomic barriers – Poverty and social deprivation reduce engagement and increase relapse risk (Stringer et al., 2023).

What Works in Treating COMHAD?

The evidence highlights several effective approaches:

Integrated care: Programmes that address both mental health and substance misuse together lead to better outcomes (Stewart et al., 2023).
Psychological therapies: CBT, motivational interviewing, and trauma-informed approaches are effective when delivered within integrated models (Marques et al., 2023).
Medication: While evidence is still limited, some pharmacological treatments show promise when carefully managed alongside psychiatric medication (Leung et al., 2023).
Holistic support: Addressing housing, employment, and social support is critical, since these factors strongly predict recovery (Stringer et al., 2023).
Early intervention: Screening in community and healthcare settings helps identify COMHAD earlier, preventing escalation (GOV.UK, 2024).

How Cheshire Sobriety Clinic Helps with COMHAD

At Cheshire Sobriety Clinic, we recognise COMHAD as the reality for many of our clients. Our approach is designed to meet both mental health and substance use needs in an integrated and compassionate way:

Comprehensive assessment: We identify both alcohol/drug use and underlying mental health concerns.
Therapeutic integration: Our programme includes counselling and Rapid Transformational Therapy (RTT®), helping clients address both emotional distress and addictive behaviours.
Relapse prevention: By targeting both mental health triggers and cravings, we give clients practical tools for sustainable recovery.
Flexible support: Sessions can be delivered online or in person, making care accessible.
Collaborative pathways: When medical or psychiatric input is needed, we link clients with trusted professionals for joined-up care.

Conclusion

COMHAD, co-occurring mental health, alcohol, and drug problems, is one of the most pressing challenges facing health and social care today. Far from being rare, COMHAD is the reality for the majority of people in substance misuse treatment. The evidence is clear: integrated, compassionate, and holistic care delivers the best outcomes. At Cheshire Sobriety Clinic, we work with people to break free from cycles of distress, mental health symptoms and drug/alcohol dependence, offering hope and practical tools for recovery.

If you or someone you love is struggling with COMHAD, know that support is available and recovery is possible.

References

GOV.UK (2024) Adult substance misuse treatment statistics 2023 to 2024: Report. London: Department of Health and Social Care. Available at: https://www.gov.uk/government/statistics/substance-misuse-treatment-for-adults-statistics-2023-to-2024/adult-substance-misuse-treatment-statistics-2023-to-2024-report (Accessed: 15 September 2025).

Katz, S., Mauro, C., Han, B. and Blanco, C. (2025) ‘Treatment use among U.S. adults with a substance use disorder: Associations with symptom severity, problem self-perception, comorbid mental illness, and mental health treatment’, International Journal of Environmental Research and Public Health, 22(4), 640.

Leung, J., Chiu, C., Douglas, L. and Ling, W. (2023) ‘Psychiatric comorbidities of substance use disorders: Does dual diagnosis predict inpatient detoxification outcomes?’, International Journal of Mental Health and Addiction, 21, pp. 3785–3799.

Marques, A., Ribeiro, J. and Martins, C. (2023) ‘Recent advances in dual disorders (addiction and other mental disorders)’, Journal of Clinical Medicine, 12(9), 3315.

National Institutes of Health / National Institute of Mental Health (NIH/NIMH) (2023) New NIH study reveals shared genetic markers underlying substance use disorders. Available at: https://www.nimh.nih.gov/news/science-news/2023/new-nih-study-reveals-shared-genetic-markers-underlying-substance-use-disorders (Accessed: 15 September 2025).

Office for Health Improvement and Disparities (OHID) (2025) Co-occurring substance misuse and mental health issues profile: September 2025 update. London: OHID. Available at: https://www.gov.uk/government/statistics/announcements/co-occurring-substance-misuse-and-mental-health-issues-profile-september-2025-update (Accessed: 15 September 2025).

Royal College of Psychiatrists (2025) CoSUM report: People with substance use and mental health disorders suffering harm and premature death after being excluded from care. London: RCPsych. Available at: https://www.rcpsych.ac.uk/news-and-features/latest-news/detail/2025/05/13/people-with-substance-use-and-mental-health-disorders-suffering-harm-and-premature-death-after-being-excluded-from-care--warns-rcpsych (Accessed: 15 September 2025).

Santucci, C., Hasin, D., Magidson, J. and Stokes, P. (2024) ‘Systematic review: Prevalence of comorbid substance use disorders among people with opioid use disorder’, Addiction, 119(4), pp. 1200–1215.

Stewart, R., Farris, S. and Carney, J. (2023) ‘Integrated behavioural treatments for comorbid anxiety and substance use disorders: A meta-analysis’, Drug and Alcohol Dependence, 253, 110990.

Stringer, B., McGovern, R. and Degenhardt, L. (2023) ‘Investigating social deprivation and comorbid mental health diagnosis as predictors of treatment access among patients with an opioid use disorder’, Substance Abuse Treatment, Prevention, and Policy, 18, 59.