By Dr Brendan Clifford

Journal articles

Hudson-Buhagiar K; Brett J; Spillane A; Clay S; Freestone J; Clifford B; Riches-Evans S; Ezard N; Roberts DM; Race K; Siefried KJ, 2026, '‘A fine line between euphoria and death’: a qualitative study exploring gamma-hydroxybutyrate (GHB) use among people who identify as heterosexual living in Australia', Harm Reduction Journal, 23, http://dx.doi.org/10.1186/s12954-026-01405-1

Acheson LS; Siefried KJ; Clifford B; Steele M; Fletcher K; Ezard N, 2026, 'People Seeking Treatment for Meth/Amphetamine Use Are Getting Older and Treatment Services Need to Adapt', Drug and Alcohol Review, 45, pp. e70238, http://dx.doi.org/10.1111/dar.70238

Clifford B; Deacon RM; Mammen K; Siefried KJ; Ezard N; Lintzeris N, 2026, 'Assessing the Concurrent Validity of the Australian Treatment Outcomes Profile in a Methamphetamine Dependent Treatment‐Seeking Population', Drug and Alcohol Review, 45, http://dx.doi.org/10.1111/dar.70224

Freestone J; Siefried KJ; Ezard N; Brown JA; Peacock A; Griffiths P; Gough C; Barratt MJ; Kypri S; Lyons T; Harvey CA; Clifford B, 2026, 'Building trust for rapid response: Examining how network collaboration operates within Australian drug-related early warning systems', International Journal of Drug Policy, 155, pp. 105430 - 105430, http://dx.doi.org/10.1016/j.drugpo.2026.105430

Holman T; Macdonald P; Slade D; Goncharov L; Middleton S; Watts GJ; Williams M; Carr G; Mitchell I; McErlean G; Sheppard-Law S; Jones K; Paull G; Templeton N; Rayner S; Davis S; Gao Y; You W; Kennedy R; Clifford B; Proctor R; Algoso C; Ng P; Myhill B; Lowe D; Devlin E; Lennox K; McVeigh J; Ryan M; Straiton N, 2026, 'Improving End-of-Life Care for Patients in Australian Cardiology Wards: A Retrospective Medical Record Audit', Heart Lung and Circulation, 35, pp. 845 - 854, http://dx.doi.org/10.1016/j.hlc.2026.04.111

Matepi QGJ; Clifford B; Acheson LS; McKetin R; Montebello M; Siefried KJ; Chan DKE; Olsen N; May R; Ezard N, 2026, 'Insomnia is associated with psychological distress in individuals with methamphetamine dependence', Australasian Psychiatry, 34, pp. 246 - 252, http://dx.doi.org/10.1177/10398562251406035

Freestone J; MacDonald H; Kypri S; Clifford B; Siefried KJ; Ezard N, 2026, 'Exploring the Utility and Appropriateness of Dose Thresholds for Issuing of Public Drug Alerts on High-Dose MDMA: A Qualitative Study', Drug and Alcohol Review, 45, pp. e70140, http://dx.doi.org/10.1111/dar.70140

Clifford B; Bruno R; Acheson L; Cecilio ME; Siefried KJ; Freestone J; Cornelisse VJ; Crozier B; Bath N; Ezard N, 2026, 'Substance Use and Sex Index version 2 (SUSI-2): Validation of a brief questionnaire for the measurement of behaviours associated with transmission of blood borne viruses and sexually transmitted infections', Addiction, 121, pp. 670 - 679, http://dx.doi.org/10.1111/add.70253

Smylie CS; Moller CI; McWilliams L; Clifford B; Acheson L; Chambers M; Siefried KJ; Brett J; Shakeshaft A; Roberts DM; Corliss C; Rich J; Clark SC; Manzie R; Dunlop A; Speirs B; Kay‐Lambkin F; Ezard N, 2026, 'Expanding Access to Addiction Medicine Specialist Care in Regional New South Wales, Australia Through Telehealth', Drug and Alcohol Review, 45, http://dx.doi.org/10.1111/dar.70101

Fletcher K; Freestone J; Clifford B; Ezard N; Kershaw S; Acheson LS; Karavasilis T; Siefried KJ, 2026, 'Digital health interventions for people who use methamphetamine: a scoping review', Frontiers in Psychiatry, 16, pp. 1658021, http://dx.doi.org/10.3389/fpsyt.2025.1658021

Freestone J; Zhou C; Kypri S; Howes M; Ebdon E; Purcell L; Dessauer P; Beckers C; Chapman B; Weith S; Lamb M; Clifford B; Siefried KJ; Barratt MJ; Peacock A; Sutherland R; Doumany J; Gava P; Standfield M; Kavanagh R; Dicka J; Sidaway P; Farah B; Ezard N, 2026, 'Incorporating experiential reports provided by people who use drugs into drug-related early warning systems: benefits, risks principles and approaches', International Journal of Drug Policy, 147, pp. 105098, http://dx.doi.org/10.1016/j.drugpo.2025.105098

Fletcher K; Ezard N; Siefried KJ; van der Helder S; Freestone J; Brett J; May R; Acheson L; Clifford B, 2026, 'Navigating ‘k-land’: a qualitative exploration of participants’ experiences of ketamine-assisted psychotherapy for methamphetamine use disorder', Frontiers in Psychiatry, 17, pp. 1873497, http://dx.doi.org/10.3389/fpsyt.2026.1873497

Freestone J; Siefried KJ; Drysdale K; Murray J; Ward J; Ezard N; Clifford B; Bourne A, 2026, 'Sex, Methamphetamine, and a Surge in Syphilis Among Women and Men Who Have Sex With Women: A Call to Diversify Research Addressing Sexualized Drug Use', Contemporary Drug Problems, http://dx.doi.org/10.1177/00914509261433267

Freestone J; Kypri S; Schumann JL; Franklin E; Francis C; Barratt MJ; Peacock A; Sutherland R; Clifford B; MacDonald H; Ezard N; Fletcher K; Acheson L; Siefried KJ, 2025, 'The Emergence of Novel Benzodiazepines in Australia, Evidence, Alerts, Clinical Management and Harm Reduction—A Narrative Review', Drug and Alcohol Review, 45, http://dx.doi.org/10.1111/dar.70086

Acheson LS; Siefried KJ; Lintzeris N; Dunlop AJ; Haber PS; Arunogiri S; Christmass M; Doyle M; Donoghoe M; Nagle J; Clifford B; McKetin R; Lubman DI; Brett J; Taylor N; Carr A; Levin FR; Shoptaw S; Ezard N, 2025, 'Study protocol for a randomised controlled trial to determine the efficacy of lisdexamfetamine for the treatment of acute methamphetamine withdrawal in inpatient settings', BMJ Open, 15, pp. e107242 - e107242, http://dx.doi.org/10.1136/bmjopen-2025-107242

Freestone J; Siefried KJ; Peacock A; Fletcher K; Barratt MJ; Sutherland R; Ezard N; Doumany J; MacDonald H; Kypri S; Acheson L; Clifford B, 2025, 'From environmental disasters to emerging drugs; a framework to understand, map and assess drug-related early warning systems', International Journal of Drug Policy, 145, pp. 104946, http://dx.doi.org/10.1016/j.drugpo.2025.104946

Chalabianloo F; Fadnes LT; Mordal J; Spigset O; Løberg EM; Halmøy A; Lid TG; Andersen CD; Daltveit JT; Assmus J; Erga AH; Solli KK; Askjer JF; Hansen MAK; Ohldieck C; Ezard N; Lintzeris N; Johansson KA; Siefried K; Clifford B, 2025, 'Impact of dextroamphetamine substitution on the use of illicit amphetamines in adults with amphetamine dependence: a study protocol for the multicentre double blind randomised controlled trial ATLAS4Dependence', BMJ Open, 15, pp. e095383, http://dx.doi.org/10.1136/bmjopen-2024-095383

Clifford B; Searby A, 2025, 'Nursing Preparedness for Emerging Drugs of Concern.', J Addict Nurs, http://dx.doi.org/10.1097/JAN.0000000000000668

Ezard N; Siefried KJ; Clifford B, 2025, 'Commentary on Young et al.: Clinical guidance is required for stimulant co-prescription with opioid agonist therapy', Addiction, 120, pp. 1195 - 1197, http://dx.doi.org/10.1111/add.70061

Clifford B; Peacock A; Siefried KJ; Gobeil J; Smith JL; Ezard N, 2025, 'Responding to reports of nitazene toxicity in Australia', Medical Journal of Australia, 222, pp. 216 - 219, http://dx.doi.org/10.5694/mja2.52605

Fletcher K; Ezard N; Siefried KJ; MacDonald H; Acheson L; Bedi G; Guerin A; Knock E; Millard M; May R; Brett J; Doumany J; Morgan C; Clifford B, 2025, 'Protocol of an open-label safety and feasibility pilot study of ketamine-assisted psychotherapy for methamphetamine use disorder (the KAPPA trial)', BMJ Open, 15, pp. e092504, http://dx.doi.org/10.1136/BMJOPEN-2024-092504

Siefried KJ; Acheson L; Clifford B; Moller C; Brett J; Christmass M; Dunlop AJ; Haber PS; Jutras-Aswad D; Lintzeris N; Morley K; Shoptaw S; Trivedi MH; Ezard N, 2025, 'Trial protocol of an open-label pilot study of oral naltrexone–bupropion combination pharmacotherapy for the treatment of methamphetamine use disorder (the NABU trial)', BMJ Open, 15, pp. e092032, http://dx.doi.org/10.1136/BMJOPEN-2024-092032

Siefried KJ; Hill P; Clifford B; Brown J; Camilleri A; Crawford S; Dessauer P; Dilkes-Frayne E; Freestone J; Gobeil J; Harrod ME; Hudson S; Hull P; Lenton S; Lyons T; Oh G; Peacock A; Pierce A; Sidaway P; Soderstrom J; Tzanetis S; Ezard N, 2025, 'Co-design of the Australian Prompt Response Network for a public-health focused intersectoral approach to information sharing on emerging drugs of concern', Frontiers in Public Health, 13, pp. 1521911, http://dx.doi.org/10.3389/fpubh.2025.1521911

Ezard N; Clifford B; Siefried KJ; Ali R; Dunlop A; McKetin R; Bruno R; Carr A; Ward J; Farrell M; Graham R; Haber P; Lubman D; Donoghoe MW; Olsen N; Baker A; Hall M; Arunogiri S; Lintzeris N; Gill A; Rodgers C; Montebello M; Liaw W; Liu Z, 2025, 'Lisdexamfetamine in the treatment of methamphetamine dependence: A randomised, placebo-controlled trial', Addiction, 120, pp. 1345 - 1359, http://dx.doi.org/10.1111/add.16730

Siefried KJ; Bascombe F; Clifford B; Liu Z; Middleton P; Kay-Lambkin F; Freestone J; Herman D; Millard M; Steele M; Acheson L; Moller C; Bath N; Ezard N, 2024, 'Effect of a Smartphone App (S-Check) on Actual and Intended Help-Seeking and Motivation to Change Methamphetamine Use Among Adult Consumers of Methamphetamine in Australia: Randomized Waitlist-Controlled Trial', Jmir Mhealth and Uhealth, 12, pp. e55663 - e55663, http://dx.doi.org/10.2196/55663

Clifford B; Van Gordon K; Magee F; Malone V; Siefried KJ; Graham D; Ezard N, 2023, '“There’s a big tag on my head”: exploring barriers to treatment seeking with women who use methamphetamine in Sydney, Australia', BMC Health Services Research, 23, pp. 162, http://dx.doi.org/10.1186/s12913-023-09125-z

Bascombe F; Siefried KJ; Clifford B; Child S; Loos R; Sgouras H; Stevens L; Wilson H; Ezard N, 2023, 'Methamphetamine and emerging drugs of concern: A training needs analysis of Australian alcohol and other drug helplines', Drug and Alcohol Review, 42, pp. 1744 - 1753, http://dx.doi.org/10.1111/dar.13719

Clifford B; Wood L; Vallesi S; Macfarlane S; Currie J; Haigh F; Gill K; Wilson A; Harris P, 2022, 'Integrating healthcare services for people experiencing homelessness in Australia: key issues and research principles', Integrated Healthcare Journal, 4, pp. e000065, http://dx.doi.org/10.1136/ihj-2020-000065

Acheson LS; Siefried KJ; Clifford B; Murray E; Steele M; Clague L; Malone V; Roberts DM; Ferguson LJ; Matthews GV; Ezard N, 2021, 'One-third of people who inject drugs are at risk of incomplete treatment for Staphylococcus aureus bacteraemia: a retrospective medical record review', International Journal of Infectious Diseases, 112, pp. 63 - 65, http://dx.doi.org/10.1016/j.ijid.2021.09.012

Ezard N; Clifford B; Dunlop A; Bruno R; Carr A; Liu Z; Siefried KJ; Lintzeris N, 2021, 'Safety and tolerability of oral lisdexamfetamine in adults with methamphetamine dependence: A phase-2 dose-escalation study', BMJ Open, 11, pp. e044696, http://dx.doi.org/10.1136/bmjopen-2020-044696

Clifford B; Wilson A; Harris P, 2019, 'Homelessness, health and the policy process: A literature review', Health Policy, 123, pp. 1125 - 1132, http://dx.doi.org/10.1016/j.healthpol.2019.08.011

Malone V; Ezard N; Clifford B; Middleton S; McInnes E; Bonevski B, 2019, 'A systems change intervention for nurse-led smoking cessation care in hospitals', Collegian, 26, pp. 235 - 241, http://dx.doi.org/10.1016/j.colegn.2018.07.007

Ezard N; Dunlop A; Hall M; Ali R; McKetin R; Bruno R; Phung N; Carr A; White J; Clifford B; Liu Z; Shanahan M; Dolan K; Baker AL; Lintzeris N, 2018, 'LiMA: A study protocol for a randomised, double-blind, placebo controlled trial of lisdexamfetamine for the treatment of methamphetamine dependence', BMJ Open, 8, http://dx.doi.org/10.1136/bmjopen-2017-020723

Ezard N; Webb B; Clifford B; Cecilio ME; Jellie A; Lea T; Rodgers C; Ruth S; Bruno R, 2018, 'Substance Use and Sex Index (SUSI): First stage development of an assessment tool to measure behaviour change in sexualised drug use for substance use treatment studies', International Journal of Drug Policy, 55, pp. 165 - 168, http://dx.doi.org/10.1016/j.drugpo.2018.03.020

Ezard N; Cecilio ME; Clifford B; Baldry E; Burns L; Day CA; Shanahan M; Dolan K, 2018, 'A managed alcohol program in Sydney, Australia: Acceptability, cost-savings and non-beverage alcohol use', Drug and Alcohol Review, 37, pp. S184 - S194, http://dx.doi.org/10.1111/dar.12702

Ezard N; Dunlop A; Clifford B; Bruno R; Carr A; Bissaker A; Lintzeris N, 2016, 'Study protocol: A dose-escalating, phase-2 study of oral lisdexamfetamine in adults with methamphetamine dependence', BMC Psychiatry, 16, http://dx.doi.org/10.1186/s12888-016-1141-x

Ezard N; Dunlop AJ; Clifford B; Bruno R; Carr A; Bissaker A; Lintzeris N, 2016, 'LISDEX I: DOSE-ESCALATING, PHASE-2 STUDY OF ORAL LISDEXAMFETAMINE IN ADULTS WITH METHAMPHETAMINE DEPENDENCE', DRUG AND ALCOHOL REVIEW, 35, pp. 36 - 36, https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000398381500098&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=891bb5ab6ba270e68a29b250adbe88d1

Conference Papers

Clifford B; Acheson LS; Brener L; Siefried KJ; Steele M; Matthews G; Ezard N, 2022, 'A qualitative exploration of client and healthcare provider perspectives on why people who inject drugs with injecting-related infections discharge against medical advice', in DRUG AND ALCOHOL REVIEW, WILEY, pp. S43 - S44, https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000862018700077&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=891bb5ab6ba270e68a29b250adbe88d1

Conference Posters

Acheson L; Siefried K; Clifford B; Moller C; Brett J; Christmass M; Dunlop A; Haber P; Jutras-Aswad D; Lintzeris N; Morley K; Shoptaw S; Trivedi M; Ezard N, 2025, 'Daily smartphone assessments for substance use measurement in a methamphetamine clinical trial', New Orleans, USA, presented at The 87th Annual Scientific Meeting of the College on Problems of Drug Dependence (CPDD), New Orleans, USA, 14 June 2025 - 18 June 2025

Fletcher K; Ezard N; Siefried K; MacDonald H; Acheson L; Bedi G; Guerin A; Knock E; Millard M; May R; Brett J; Doumany J; Morgan C; Clifford B, 2024, 'An open-label safety and feasibility pilot trial of ketamine-assisted psychotherapy for methamphetamine use disorder', Canberra, Australia, presented at Australasian Professional Society on Alcohol and other Drugs (APSAD) Scientific Conference 2024, Canberra, Australia, 30 October 2024 - 02 November 2024, http://dx.doi.org/10.1111/dar.13943

Budebes M; Clifford B; Siefried K, 2024, 'The GHB cultures, experiences and practices quantitative study', Canberra, Australia, presented at Australasian Professional Society on Alcohol and other Drugs (APSAD) Scientific Conference 2024, Canberra, Australia, 30 October 2024 - 02 November 2024, http://dx.doi.org/10.1111/dar.13943

Conference Presentations

Siefried K; Acheson L; Clifford B; Moller C; Brett J; Christmass M; Dunlop A; Haber P; Jutras-Aswad D; Lintzeris N; Morley K; Shoptaw S; Trivedi M; Ezard N, 2025, 'A pilot study of the safety and feasibility of oral naltrexone and bupropion for methamphetamine use disorder', presented at The 87th Annual Scientific Meeting of the College on Problems of Drug Dependence (CPDD), New Orleans, USA, 14 June 2025 - 18 June 2025

Acheson L; Ezard N; Fletcher K; Clifford B; Steele M; Moses M; Siefried K, 2024, 'A heuristic for evaluating methamphetamine withdrawal treatment programs', presented at Australasian Professional Society on Alcohol and other Drugs (APSAD) Scientific Conference 2024, Canberra, Australia, 30 October 2024 - 02 November 2024, http://dx.doi.org/10.1111/dar.13943

Broadbent E; Siefried K; Ezard N; MacDonald H; Gobeil J; Clifford B, 2024, 'Implementing a national Prompt Response Network to improve health-led decision making and processes for emerging drugs', presented at Australasian Professional Society on Alcohol and other Drugs (APSAD) Scientific Conference 2024, Canberra, Australia, 30 October 2024 - 02 November 2024, http://dx.doi.org/10.1111/dar.13943

Clifford B, 2024, 'Emerging drugs of concern - Prompt Response Network update', presented at 2024 NDARC Annual Research Symposium, Wesley Conference Centre, Sydney NSW, 20 September 2024, https://www.youtube.com/watch?v=vxBO7_cTwPU&t=3141s

Siefried K; Clifford B; Acheson L; Ezard N, 2023, 'Innovations beyond BC: Lisdexamfetamine for the treatment of methamphetamine use disorder and withdrawal', presented at The 5th Annual BC Substance Use Conference, Vancouver, Canada, 20 April 2023 - 23 April 2023

Hill P; Clifford B; Brown J; Dessauer P; Oh G; Lyons T; Herbert A; McKinnon G; Lamb M; Crawford S; Mason C; Siefried K; Ezard N, 2023, 'Strength in solidarity: Bringing together diverse local stakeholders to disseminate public drug information (presented on behalf of the Prompt Response Network)', presented at Harm Reduction International, Melbourne, Australia, 16 April 2023 - 19 April 2023, https://hr23.hri.global/programme/

Bascombe F; Siefried K; Clifford B; Middleton P; Liu Z; Wilson J; Steele M; Kay-Lambkin F; Ezard N, 2022, 'Feasibility and efficacy of the S-Check App to change help seeking behaviour of people who use methamphetamine', presented at Lisbon Addictions, Lisbon, Portugal, 23 November 2022 - 25 November 2022

Ezard N; Clifford B; Siefried K; Acheson L, 2022, 'Safety and tolerability of lisdexamfetamine for  methamphetamine dependence and withdrawal, early experience from Australia: The LiMA Trial and OLAM pilot', presented at Annual Meeting Conference of the Norwegian Association for Addiction Medicine, Bergen, Norway, 02 November 2022

Conference Abstracts

Clifford B; Ousley R; May R; Olsen N; Siefried K; Ezard N, 2025, 'Association Between Age of First Methamphetamine Use and Childhood Attention Deficit Hyperactivity Disorder Symptomatology—An Exploratory Study in a Clinical Trial Cohort', Sydney, Australia, presented at APSAD 2025 Conference, Sydney, Australia, 09 November 2025 - 12 November 2025, http://dx.doi.org/10.1111/dar.70014

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