A clinician’s guide to medication assisted treatment for drug addiction

Drug addiction is not a matter of choice or moral failing; it is a complex, chronic condition rooted in neuroadaptive changes within the brain. Repeated substance use alters neural pathways, particularly those governing reward, motivation, and executive function, leading to compulsive behaviours and a diminished capacity for self-regulation¹

• In England and Wales, the prevalence of drug use remains a significant public health concern. 
• As of March 2023, approximately 9.5% of individuals aged 16 to 59 years reported using drugs within the past year, equating to around 3.1 million people ²
• Notably, 3.3% of this demographic had used Class A substances, such as heroin or cocaine, during the same period. ​
• Between April 2022 and March 2023, over 290,000 adults in England engaged with drug and alcohol treatment services ³ reflecting the widespread nature of substance misuse.

Public figures have begun to shed light on the realities of drug addiction, emphasising its nature as a health issue rather than a personal failing. The Princess of Wales, Kate Middleton, has highlighted the importance of compassion and support for those living with addiction ^4.

“For too long, many have suffered in silence, harboring feelings of shame and guilt about their condition, despite their vulnerability.”

• Kate Middleton 

Recognising addiction as a neuroadaptive disorder underscores the necessity for comprehensive, evidence-based treatment approaches. Medication assisted treatment (MAT) addresses the physiological aspects of dependence, while psychosocial interventions, such as cognitive-behavioural therapy, target the behavioural and psychological components. Together, these strategies form a whole-person framework essential for effective recovery.

If you have a client who may benefit from medication assisted treatment for drug addiction, contact us to make a referral today. 

Medication assisted treatment: mechanisms, modalities, & neurochemical targets

Medication assisted treatment (MAT) refers to the use of FDA-approved pharmacological interventions alongside psychological and behavioural therapies to treat substance use disorders5 – most notably opioid use disorder (OUD). In UK-based clinical settings, this approach is increasingly recognised as a cornerstone of evidence-based addiction treatment, endorsed by NICE⁶ and supported by public health bodies in the UK⁷.

MAT addresses the core neurochemical disruptions caused by chronic drug use – not merely suppressing symptoms, but actively stabilising brain function and enabling engagement ⁸ in psychosocial recovery.

Neurochemical dysregulation in addiction

Chronic exposure to substances like heroin or prescription opioids leads to significant dysregulation in the brain’s reward circuitry ⁹, particularly:

• Dopaminergic pathways – blunted dopamine signalling contributes to anhedonia and drug-seeking behaviour.
• Mu-opioid receptor activity – dysregulated receptor activity impairs pain modulation, mood, and stress response.
• Hypofunction in prefrontal regions – impaired executive function compromises decision-making and impulse control.

These adaptations make abrupt abstinence not only intolerable for many patients but neurobiologically unsustainable without clinical support ¹⁰.

Key medications used in MAT, & their mechanisms

→ Buprenorphine

A partial mu-opioid receptor agonist with high receptor affinity and a ceiling effect, buprenorphine reduces cravings and withdrawal symptoms without producing full opioid euphoria. It displaces full agonists like heroin or morphine and is associated with improved safety¹¹ in overdose settings.

→ Methadone

A full opioid agonist that stabilises opioid levels in the bloodstream, methadone reduces the highs and lows associated with short-acting opioids. Despite its potential for misuse, it remains a mainstay in opioid treatment programmes ¹² due to its efficacy in retention and relapse prevention.

→ Naltrexone

An opioid receptor antagonist that blocks the effects of exogenous opioids. While effective in relapse prevention¹³, adherence remains a clinical challenge – especially in oral form. Extended-release injectable formulations are being explored for improved outcomes.

→ Naloxone (adjunctive use)

While not a maintenance medication, naloxone is a critical harm-reduction tool, reversing opioid overdoses by rapidly displacing opioids from mu-receptors¹⁴. Increasing availability via community programmes and take-home kits is saving lives across the UK.

Beyond opioids –  MAT for other substances

While MAT is most commonly associated with OUD, pharmacotherapies are increasingly applied to alcohol use disorder (eg., acamprosate, disulfiram)¹⁵ and emerging trials are exploring utility in stimulant use disorders¹⁶. Though results remain mixed¹⁷, targeting specific neurotransmitter systems (eg., GABA, glutamate, norepinephrine) continues to inform future protocols.

Clinical indications for MAT

Medication assisted treatment (MAT) is indicated for individuals diagnosed with moderate to severe opioid use disorder (OUD), based on established diagnostic criteria such as those outlined in the DSM-5¹⁸. MAT may also be appropriate in cases involving:

• Recurrent relapse following abstinence-based treatment
• Co-occurring mental health conditions (eg., depression, PTSD)
• High risk of overdose or previous overdose events
• Chronic pain with opioid misuse
• Limited access to psychosocial care in rural or underserved areas

Initiating MAT should follow a comprehensive assessment that includes substance use history, physical and psychiatric evaluation, and psychosocial needs.

Contraindications & cautions

While MAT is broadly safe when prescribed appropriately, there are clinical scenarios that may require caution¹⁹ or warrant alternative approaches:

• Active hypersensitivity to specific medications (eg., buprenorphine, methadone)
• Severe respiratory insufficiency in methadone initiation
• Hepatic impairment, particularly with naltrexone use
• Concurrent use of CNS depressants (eg., benzodiazepines), which may increase sedation and overdose risk
• Lack of opioid dependence, particularly for antagonist-based therapies such as naltrexone, which can precipitate withdrawal if opioids are present

A period of abstinence (typically 7–10 days) is required prior to naltrexone initiation to avoid acute withdrawal.

Psychosocial integration

Medication assisted treatment (MAT) is most effective when embedded within a broader, person-centred care plan²⁰ that includes psychosocial support. 

Pharmacotherapy addresses neurochemical dysregulation, but it does not resolve the behavioural, psychological, and social drivers of substance use. Without concurrent psychosocial interventions, long-term recovery outcomes are significantly compromised²¹.

Why integration matters

In addition to the active pharmacological mechanisms that occur within MAT, complementary psychosocial support serves to:

• Enhance treatment engagement and retention
• Reduce risk of relapse by targeting maladaptive thought patterns and behaviours
• Address co-occurring mental health conditions (eg., anxiety, depression, trauma)
• Strengthen coping mechanisms and emotional regulation
• Improve quality of life, housing stability, employment, and relationships

Data consistently shows²² that combining MAT with psychosocial care produces superior outcomes to either modality alone²³. NICE, WHO, and SAMHSA all recommend integrated approaches as the gold standard.

Recommended psychosocial modalities

The following therapies are commonly used alongside MAT:

• Cognitive behavioural therapy (CBT): targets distorted thinking, avoidance behaviours, and coping deficits
• Motivational interviewing (MI): builds internal motivation and supports readiness for change²⁴
• Contingency management: reinforces abstinence through structured incentives
• Trauma-informed approaches: crucial for individuals with histories of ACEs or PTSD²⁵

At every stage of the recovery journey, psychosocial integration ensures treatment is not merely about symptom suppression, but about building resilience, restoring autonomy, and supporting long-term reintegration.

Integrating MAT Into multidisciplinary, whole-person care

Ultimately, medication assisted treatment (MAT) should not be viewed as a standalone ‘fix’ – rather, it’s a clinically validated cornerstone of a broader, multidisciplinary approach to treating drug addiction26. When integrated with evidence-based psychosocial interventions, MAT helps stabilise neurobiology, reduce harm, and create space for meaningful psychological and social recovery.

For practitioners, effective implementation means viewing MAT as part of a dynamic, person-centred care model.

As drug-related deaths continue to rise in the UK, the case for expanding MAT access is not just clinical: it is ethical. Reframing MAT as an enabler of long-term recovery, rather than a substitute or crutch, is essential for shifting public perception, health policy, and service delivery.

In the hands of skilled, compassionate teams, MAT becomes more than medication. It becomes an entry point to hope, stability, and the possibility of a life beyond addiction. Contact us now to learn more or to refer a client. 

References

1. https://www.mayoclinic.org/diseases-conditions/drug-addiction/symptoms-causes/syc-20365112#:~:text=Drug%20addiction%2C%20also%20called%20substance,nicotine%20also%20are%20considered%20drugs.
2. https://commonslibrary.parliament.uk/research-briefings/cdp-2024-0050/#:~:text=According%20to%20the%20Office%20for,using%20a%20Class%20A%20drug.
3. https://www.gov.uk/government/statistics/substance-misuse-treatment-for-adults-statistics-2022-to-2023/adult-substance-misuse-treatment-statistics-2022-to-2023-report
4. https://people.com/kate-middleton-speaks-up-for-people-addiction-during-her-cancer-recovery-8753172 
5. https://americanaddictioncenters.org/addiction-medications
6. https://www.nice.org.uk/advice/es19/evidence/evidence-review-pdf-6666819661
7. https://rightdecisions.scot.nhs.uk/tam-treatments-and-medicines-nhs-highland/adult-therapeutic-guidelines/mental-health/substance-misuse-guidelines/medication-assisted-treatment-mat-guidelines/
8. https://nida.nih.gov/publications/research-reports/medications-to-treat-opioid-addiction/how-do-medications-to-treat-opioid-addiction-work
9. https://nida.nih.gov/publications/research-reports/medications-to-treat-opioid-addiction/how-do-medications-to-treat-opioid-addiction-work
10. https://www.sciencedirect.com/science/article/pii/S0092867415009629
11. https://psychiatry.uams.edu/clinical-care/outpatient-care/cast/buprenorphine/#:~:text=Buprenorphine%20is%20used%20in%20medication,as%20pain%20relievers%20like%20morphine.
12. https://psychiatryonline.org/doi/10.1176/appi.ps.201300235
13. https://www.ncbi.nlm.nih.gov/books/NBK574913/
14. https://www.communitypharmacy.scot.nhs.uk/nhs-fife/pages/addiction-services/naloxone/
15. https://pmc.ncbi.nlm.nih.gov/articles/PMC6032529/
16. https://pubmed.ncbi.nlm.nih.gov/31008728/
17. https://www.tandfonline.com/doi/full/10.1080/00952990.2017.1362419
18. https://www.asam.org/docs/default-source/education-docs/dsm-5-dx-oud-8-28-2017.pdf
19. https://pmc.ncbi.nlm.nih.gov/articles/PMC10467182/
20. https://pmc.ncbi.nlm.nih.gov/articles/PMC4795974/
21. https://aspe.hhs.gov/reports/psychosocial-supports-medication-assisted-treatment-recent-evidence-current-practice-0
22. https://pmc.ncbi.nlm.nih.gov/articles/PMC4866634/
23. https://pmc.ncbi.nlm.nih.gov/articles/PMC5244449/
24. https://harborlondon.com/motivational-interviewing-drug-addiction/
25. https://harborlondon.com/the-link-between-childhood-trauma-and-adult-behaviour/
26. https://www.matstandards.co.uk/