ICDD2022 will cover all aspects of evidence-based treatment of Dual Disorders. A renowned faculty will offer the delegates a wide selection of scientific and interactive sessions.

Thursday 29 Sep

day’s chairman: Niels Mulder, Psychiatrist, Professor of Public Mental Health Epidemiological and Social Psychiatric Research institute, Erasmus MC/Parnassia Psychiatric Institute





Erik Masthoff, Director, Fivoor, the Netherlands


ADHD and Addiction: Epidemiologu, Neurobiology and Treatment

Wim van den Brink, Professor of Psychiatry and Addiction, AMC Amsterdam, the Netherlands

ADHD and substance use disorders (SUDs) are highly comorbid with 20-25% of all SUD patients also meeting criteria for adult ADHD (van Emmerik-van Oortmerssen et al., 2012) and about 50% of the patients with childhood ADHD developing SUD (Manuzza et al., 2008). This high level of concurrent and prospective comorbidity is largely explained by genetic overlap (Derks et al., 2014; Abdellaoui et al., 2020). Moreover, prospective clinical and retrospective register studies suggest that early treatment of ADHD with robust doses of stimulants may prevent or postpone the development of SUD in children with ADHD (Groenman et al., 2013, 2019; Zheng Chang et al., 2014). Together these findings suggest that ADHD and SUD share neurobiological mechanisms.

In this presentation, we explore the neurobiological overlap between ADHD and SUD using data from cross-sectional and prospective neurocognitive and neuroimaging studies. The neurobiology of both ADHD and SUD can be summarized as a combination of an impaired motivational and reward system and a deficient cognitive control system, including impairments of delay discounting and error monitoring (Frodl, 2010; Moline & Pelham, 2014; Adisetiyo & Gray, 2017).

Patients with both disorders also show reduced dopamine transporter binding of methylphenidate (Crunelle et al., 2013) causing reduced efficacy of standard doses of stimulants for the treatment of ADHD patients with comorbid SUD explaining the need for high dose stimulant treatment in these comorbid patients (Carpentier & Levin, 2017; Levin et al., 2015; Konstenius et al., 2014). Finally, a recent paper showed better ADHD outcomes in comorbid SUD+ADHD patients treated with integrated cognitive behavior therapy (iCBT) (van Emmerik-van Oortmerssen et al., 2019).


Coffee break & intermezzo


The Neurosequential Model of Therapeutics in Dual Disorder treatment

Tony Bloemendaal, clinicial Psychologist/Psychotherapist - PhD student, Director of postgraduate training at Fivoor

Background: People with a dual disorder (comorbidity of addiction and other psychiatric afflictions) have less treatment adherence, more morbidity, somatic complaints and psychosocial problems (Norman et al, 2012). This is in part caused by an underestimation of the influence of trauma and neglect. The Neurosequential Model of Therapeutics (Perry, 2009; Perry and Dobson, 2013) incorporates early trauma and neglect in the assessment of current functioning.

Aims: To describe the role of trauma and neglect in the treatment of patients with dual disorders. And also, to investigate the possible role of the Neurosequential Model of Therapeutics in understanding the high dropout and treatment nonresponse within this group of patients.

Method: The relevant literature is presented and discussed.

Conclusion: The Neurosequential Model of Therapeutics may be helpful in understanding the often found connection between trauma and neglect, and addiction and treatment nonresponse.

Norman, S.B., Myers, U.S., Wilkins K.C., Goldsmith, A.A., Histova, V., Huang, Z., McCullough, K.C., Robinson, S.K. (2012). Review of Biological Mechanisms and Pharmacological Treatments of Comorbid PTSD and Substance Use Disorder. Neuropharmacology 62 (2): 542 – 551.

Perry, B.D. (2009). Examining child maltreatment through a neurodevelopmental lens: Clinical application of the Neurosequential Model of Therapeutics. Journal of Loss and Trauma 14: 240–255.

Perry, B.D., Dobson, C. (2013). Application of the Neurosequential Model (NMT) in maltreated children. In J. Ford en C. Courtois (Eds.), Treating Complex Traumatic Stress Disorders in Children and Adolescents. New York: Guilford Press.


Contingency Management as an effective intervention in Dual Disorders treatment

Geert Dom, Medical Director, Psychiatric Center Multiversum & University of Antwerp, Belgium

Substance use disorders (SUD) are highly prevalent among patients with severe psychiatric disorders and are associated with poorer clinical and functional outcomes. Effective interventions for this clinical population are scarce and challenging. Contingency management (CM) is one of the most evidence-based treatments for SUD’s. Increasingly evidence is growing that CM might be an effective behavioural intervention for patients with these complex co-morbidities. In the presentation we will highlight the current state of CM in different dual disorder populations and present data from a recent meta-analysis of the effect of CM in patients with a dual diagnosis of psychotic disorder and SUD.



14:00 - 15:00 Parallel session I


1.2 The psychedelic renaissance; our personal experiences

Tatja Hendriks, Psychotherapist, Fivoor/Parnassia

There is quite a taboo around talking about our own psychiatric illnesses or addiction in general, for care providers in particular. There might even be a bigger taboo around the personal use of psychedelics. Yet the last couple of years a renaissance has been going on. After years of being banned, new research is being done into the effects of psychedelics, and psychedelic-assisted psychotherapy is gaining ground. Few therapists will talk about their own experiences with psychedelics though, partly because of the illegal status of many of these substances.

But would you like to learn surfing from a surf-teacher who has only read books about surfing?

So let’s talk… mdma, psilocybine, ketamine, ayahuasca, iboga, lsd etc.


1.3 Treating trauma and addiction: the effect of seeking-safety on PTSD and substance abuse

Annette Bonebakker, PhD, clinical neuropsychologist, EMDR practitioner and researcher, Center of Dual Disorder in The Hague

Trauma in combination with addiction is an underestimated problem, while these patients often suffer from severe symptoms and severe psycho-social problems. Patients with these dual disorders are either treated in addiction health care, or in psychiatric health care. As a consequence their disorders are treated separately while there is compelling scientific evidence that these disorders overlap. Drawing a hard line between psychiatric health and addiction is therefore, not realistic (Kok e.a. 2015).

Dual disorders (i.e. psychiatry and addiction) treated at the same time as co-occuring psychopathology leads to better treatment outcome (Neven e.a. 2018).

Seeking Safety is the first evidence based integrated treatment for trauma and addiction. (Najavits e.a. 2005; Najavits e.a. 2010). At the centre for Dual Disorders in The Hague, we study the effect of seeking safety on PTSD and on substance abuse in dual disorder patients. We are especially interested in the treatment outcome of seeking safety as a group treatment. We plan to include 40 patients in this study.


1.4 HPPD, VSS and DPS: detection, diagnostics and treatment of persistent perception disorders after use of recreational drugs

Gerard Alderliefste, Physician in addiction medicine

Drs. Gerard Alderliefste (1964, Amsterdam) ) has been an addiction doctor at Brijder, centre for addiction treatment, since 1992.  For 14 years he deals with heroin and polydrug addicted people and provides education for employees. Since 2008 he has run the LMSP, the National Medical Recreational drugs consultation, where persisting symptoms after drug use become his specialization. These concern the diagnoses HPPD (Hallucinogen Persisting Perception Disorder), VSS (Visual Snow Syndrome) and DPS (depersonalization-derealization disorder). Gerard worked together with HPPD pioneer psychiatrist dr Abraham, who retired and often refers patients that seek for help that is hard to find.  Collaboration takes place with neurologists of the LUMC in Leiden concerning visual snow research. Contributions to six scientific publications are made among which two in English ( 1,2).  In addition, he regularly appears as a specialist on Dutch television, radio and press and gives countless lectures. Thousands of drug-related questions (mainly about pharmacological interactions between drugs and regular medication) are answered on Besides, Gerard is a professional musician.

The proposed treatment plan after a teleconsultation is based on a bio-psychosocial approach. Meaning that there will be focus at biological both as psychological contributing factors that do maintain the perceptional disturbances. The treatment plan provides 4 steps:

  1. Information/explanation
  2. Life style advices (self-help)
  3. Therapy (external help)
  4. Medication


1). Hallucinogen persisting perception disorder and the serotonergic system: A comprehensive review including new MDMA-related clinical cases
Ruud P.W. Litjensa,b , Tibor M. Bruntb , Gerard-Jan Alderliefste , Remco H.S. Westerink. Neurotoxicology Research Group, Toxicology Division, Utrecht, The Netherlands

2). Migraine prevalence in visual snow with prior illicit drug use (hallucinogen persisting perception disorder) versus without
Robin M. van Dongen | Gerard J. Alderliefste | Gerrit L. J. Onderwater |
Michel D. Ferrari | Gisela M. Terwindt


1.5 Heppie and Heidi, two pigs on a ward. A qualitative study of experiences of patients and staff

Nicole Hartmann, mentor, Fivoor and Nienke Kool, PhD, sr. Researcher, Fivoor, Parnassia Groep and Inholland University of Applied Sciences

Introduction: In 2018, in a centre for patients with dual disorder, two pigs were added to the treatment program. The aim was to learn patients to take responsibility but also for distraction and recreation.

Aims: To evaluate what the presence of the pigs means for the patients of a centre for dual disorder and what it adds to the treatment program.

Methods: A qualitative design with thematic analysis was used. Two focus-group interviews were held, one with patients (N=7) and one with staff (N=7). The study took place in close co-operation with the client council.

Results: Two themes emerged: taking care of the pigs and therapeutic effect. Both groups agree about the therapeutic effect: it is experienced as added value in difficult times. The groups differ about the impact of the caring theme. Where staff experience the care as an extra task which costs effort and time, patients experience it as important, giving them satisfaction, distraction and something to do.

Conclusion: Overall, the presence of the pigs are seen as added value for the patients. We recommend to consider upfront what kind of animal is suitable for the patients and setting. Animal welfare is as important as human welfare.


Guided tour CDP, Mangostraat 5

maximum 15 places available, based on pre-registration

Shuttle service to Mangostraat 5 at 13.00h, guided tour of 60 minutes, Shuttle service back at 14:30h. Lunch is arranged for at Mangostraat.


Beating the stigma of substance use disorder

Patrick Corrigan, Distinguished Professor of Psychology, Illinois Institute of Technology, USA

Unlike other behavioral health conditions, the stigma of substance use disorder (SUD) may be especially resilient to change because it is socially and legally sanctioned. After a brief overview addressing the “What” of SUD stigma, I consider measures on “How” to change it. I summarize what research shows about methods that seem to have little effect or actually may make stigma worse; e.g., educate the public that SUD is a brain disorder. I then describe one effective approach to stigma change: promoting contact between people with SUD and the general public. This requires strategic disclosure of SUD experiences for this approach to go big scale.


Coffee Break & intermezzo

16:15 - 17:15 Parallel session II


2.1 Addiction, assessment, and treatment: two methodological applications to better understand changes in crime related factors in forensic SUD and non-SUD populations

Stefan Bogaerts, professor, Tilburg School of Social and Behavioral Sciences, the Netherlands

Addiction, assessment, and treatment: two methodological applications to better understand changes in crime related factors in forensic SUD and non-SUD populations

Because of the very complex relationship between substance use disorders (SUD), comorbid mental health problems, and criminal recidivism in forensic patients, personalized statistical approaches are indicated and needed.
First, latent class analysis investigates whether homogeneous patient classes can be identified from a large heterogeneous group of forensic patients. In our study, several homogeneous classes were identified that differ in the risk of recidivism, Axis I and II diagnoses and type of drug use. This information can be a first step towards more refined personalized treatment, with the restriction that the information does not teach us much about associations between these factors.
Second, we therefore share information about the dynamic associations between individual clinical risk and protective factors and the centrality of these factors in a group of patients diagnosed with SUD and without SUD using network analyses. This will give us insights into changes in associations between factors over time, and together, we can discuss how treatment can contribute to changes in associations and centrality of factors in both groups.

The workshop mainly strives for interaction and learning from each other.

Jankovic, M., van Boxtel, G., Masthoff, E., De Caluwe, E., Bogaerts, S. (2021). The Long-Term Changes in Dynamic Risk and Protective Factors Over Time in a Nationwide Sample of Dutch Forensic Psychiatric Patients. Frontiers in Psychiatry, 12, Article Number737846, https://doi: 10.3389/fpsyt.2021.737846
Jankovic, M., Masthoff, E., Spreen, M., de Looff, P., & Bogaerts, S. (2021). Latent Class Analysis of Forensic Psychiatric Patients in Relation to Risk and Protective Factors. Frontiers in Psychology, 12, Article Number 695354. htpps://doi: 10.3389/fpsyg.2021.695354
Schmitter, M., Vermunt, J., Blaauw, E., & Bogaerts, S. (2021), “Risk classes of patients diagnosed with substance use disorders in Dutch forensic psychiatric centers”, The Journal of Forensic Practice, 23(1), 39-52.
Bogaerts, S., Spreen, M., Masthoff, E., & Jankovic, M. (2020). Longitudinal Network Structure and Changes of Clinical Risk and Protective Factors in a Nationwide Sample of Forensic Psychiatric Patients. International Journal of offender therapy and Comparative Criminology, 64(15), 1533-1550.


2.2 Memories of the Sun’s secretary

Gijs Nooitgedagt, experience expert, Parnassia

Moving to the Dutch city of Delft in 1.998, to study mechanical engineering, I had found a student house to live with 17 housemates. Being used to drink a lot of alcohol in the weekends with friends in my hometown, in the student house I was introduced with cannabis. I remember my first smoking weed and having a burst into laughter, a ‘lachkick’ we say in Dutch, to keep laughing out loud for quite a while, thinking all the ordinary is so funny!

Quite soon smoking joints become a problem. My study did not have a real launch, I barely finished any exams. But listening to music being stoned was so much more intense. It was pleasant to fantasize about all kind of things and masturbating was also more intense.

Having stress due to lying about my not achieved study results, stress of missing a sweet girlfriend to share life and to be intimate with. I was changing in how to deal with all the negative of our world as it also comes to us by the media. Why is there so much misery in our World? If most people grow up in loving and caring homes, why and how all the aggression and indifference on our planet? Why all the lack of love!

I could fantasize a lot about writing a book which would contribute strongly to World Peace. Being a fan of Star Trek Voyager series, I fantasized about travelling through space meeting all kinds of friendly and interesting aliens.

Suddenly the terror attacks of nine eleven 2.001 occurred. By this it went much further downwards with me, questioning how it was possible the Twin Towers collapsed with gravitational acceleration, as if the metal constructions did not have any resistance against collapse; was all this a false flag operation? I quit attending classes and started smoking joints all day, following the news intensively. A few months later, February 2.002, a voice appeared in my head, introducing herself as our Sun and explained the following:

The intelligent Sun, who directs all life on Earth, as stars are used to do with life on their surrounding planets, was suffering from an internal stellar infection called Alf. Alf was evil and responsible for all the negative in the Sun and on our World.

Infected stars are a common horror-problem in the Milky Way and far beyond, all over the Cosmos many stars are suffering from Alf-like infections. The Sun had been in war with Alf for millions of years, as the period with the dinosaurs was also a rough moment in time, all to get back her autonomy and being free of Alf his horror-influences.

My birth was planned millions of years ago, in the fight between the Sun and Alf the Sun had conquered my birth to be determined in 1.974 AC (After Christ). I was born as the Sun’s secretary. As she explained to me by her voice in my head, I had a key position to help the Sun to get rid of Alf and to install Peace on Earth.

What happened next, and what I am going to tell you about, was me being in the trenches of a totally insane war, which lasted a year…


2.3 Integrated Dual Disorder Treatment: from a theoretical frame to everyday practice

Monique van Winden, GZ Psychologist in training/clinical psychologist, Parnassia and Samantha Hoogenraad, nurse Fivoor and Frouke Knetsch, nurse practitioner Fivoor

Treatment of patients with addiction and psychiatric problems requires an integrated approach. IDDT, integrated dual disorder treatment, focusses on simultaneously helping patients with their psychiatric and substance disorders. IDDT is a treatment model which doesn’t describe specific interventions but offers a fundamental base from which interventions can be deployed.  It offers health care professionals, patients and relatives holding and helps them to speak the same language.

In this workshop we translate the theorical framework of IDDT to the practical use in the daily life in a clinical treatment program. There will be time to embay your own casuistry or to zoom in on specific problems that can occur when you implement IDDT in a clinical program.


2.4 Family in therapy

Michel Stemkens, the Netherlands

The presentation of the NBR will be carried out by a representative. Regarding the family therapy topic, I would like to point out the importance of inviting relatives for intakes, not only to provide information about treatment options, but also in order to clarify mutual expectations. Secondly, I would like to talk about partner relation therapy and family therapy and finally I would like to address the informative family meetings with a different focus, e.g. providing information. Psychological education, for instance the relation between addiction and mental disorders and peer (or fellow suffers contact) as a form of family support.


2.5 Nitrous oxide (laughing gas) in The Netherlands

Jan van Amsterdam, Amsterdam UMC and Yll Nushi, medical doctor specialized in addiction, Arkin

Nitrous oxide (N2O: laughing gas) has been inhaled by hundreds of millions of patients in medical settings since 1844. More recently, recreational N2O use increased worldwide.

Incidental N2O use gives little or no harm, but prolonged use of high doses may lead to neurological damage, including generalized demyelinating polyneuropathy, resulting in paresthesia, and even paralysis due to spinal cord injury. Hallmark of almost all clinical cases is vitamin B12 (cyanocobalamin) deficiency. Timely supplementing with vitamin B12, is indicated.

Patients present too late to hospital, and one of the reasons is shame, notably in a small subgroup of young Muslim heavy N2O users. In addition, users shift from using standard cartridges (8 grams) to 2 kg tanks. A specific harm is the increased number of N2O related traffic accidents (from 130 in 2017 to 960 mid 2019).

Conclusion: the low level of awareness about the risks to prolonged and/or heavy N2O use, and the late presentation to treatment after experiencing side-effects is concerning. Therefore, we advocate a combined effort of legislation (reducing availability of N2O) and better education of potential users (including N2O information in existing prevention strategies) and medical professionals about side-effects to limit problems associated with (excessive) N2O use.


End of Congress day 1


Congress Dinner

Friday 30 Sep

day’s chairman: Stefan Bogaerts, professor, Tilburg School of Social and Behavioral Sciences, the Netherlands





Bastiaan van der Hoeven, director Parnassia, the Netherlands


ADHD and substance use disorder, what have we learned over the past decade of research?

Arnt Schellekens, Professor in Psychiatry and Addiction, Radboudumc, the Netherlands

ADHD and substance use disorders often co-occur and co-occurrence of these conditions has a negative impact on the course of both conditions. Yet, ADHD is still too often overlooked or ignored. An increasing scientific interest in these conditions over the past decade has furthered our understanding of this frequent comorbidity in psychiatry and yielded directions for clinical practice with regard to the diagnostic process and treatment. This lecture will provide an overview of developments in this field over the past decade, including shared heritability, reliability of the diagnostic process and effectiveness of different pharmacotherapies, including high-dose stimulant treatment.


Nicotine Addiction, Mental Health and Substance Abuse: Management in clinical practice

Renee Bittoun,Tobacco Treatment Specialist/ Consultant, Professor at Notre Dame and Avondale University, Sydney, Australia

There are myths that nicotine itself is benign in the brain and may have little impact on mental health or other substance use and abuse. This presentation will debunk these myths and describe strategies to prioritize and better manage nicotine addiction and nicotine abuse in order to improve mental health and drug and alcohol abstinence outcomes. Examples will be presented where protocols for nicotine addiction treatments have been implemented in institutions and for individuals in Mental Health, Detox and Dual Diagnosis Institutions both as out-patients and inpatients. Cases of alcohol dependence, Paranoid Schizophrenia, Long-term depression and anxiety disorder, Gambling and PTSD will be described.


Coffee Break


Integrated Dual Disorder Treatment: Looking Forward After Twenty Years of Implementation

Patrick Boyle, Consulting Director, Center for Evidence Based Practices, USA

Integrated Dual Disorder Treatment (IDDT) was researched and developed during the 1990’s and implemented as an integrated clinical practice to help people with co-occurring mental illness and substance use disorders live full lives in an evolving recovery process (Drake, Goldman, et al 2001).  While such evidence based practices have become more widely implemented across the world during the past twenty years, people with these two co-occurring disorders are still at risk of not receiving fully integrated care services for many reasons.

Looking to the future, an ongoing focus, expectation, and effort is required to: 1) rule out substance use disorders for people having mental disorders in all practice settings; 2) recruit, train and supervise all practitioners to properly detect, assess, and treat both disorders in an integrated manner, as well as other co-occurring disorders and conditions such as trauma; 3) support continuous quality improvement strategies in all practice settings to evaluate integrated practice implementation and supervision in an effective and routine manner; 4) make adjustments to services as indicated by such evaluations; 5) fully develop housing, employment, and primary health care systems to support these essential foundations to a full life for all.

Evidence Based Practices clinical interventions needed for full IDDT implementation initially included Motivational Interviewing (and its implied responsibility that all practitioners help people develop the motivation to change), Cognitive Behavioral Treatment, Substance Abuse Treatment (including tobacco cessation), Family educational interventions, Self-help 12-Step support, Pharmacological Treatment for all disorders and practices such as intensive case management, competitive employment, illness self-management recovery and leisure activities, all delivered with a stage-wise person-centered approach to care through multi-disciplinary teams (R. Drake, G. Bond, et al., 2002).

The importance of pragmatism, curiosity, self-reflection, and optimism (hope) is essential for success. We are disseminating “hope” for and with people as we continue to add to our knowledge base of integrated disorder treatment implementation.


Interventions for improving the prognosis of dual diagnosis patients

Niels Mulder, psychiatrist Professor of Public Mental Health Epidemiological and Social Psychiatric Research institute, Erasmus MC Parnassia Psychiatric Institute

Dual Diagnosis (DD) patients suffer from both psychiatric disorders such as psychosis or depression, in combination with an addictive disorder. Addictive disorders include substance abuse disorders as well as gambling. Over 50% of Severely Mentally Ill patients suffer from DD, making this a very large group. Treatment of DD is challenging, since the various disorders that are present in one patient cause negative vicious circles and making treatment of e.g. psychosis, depression, as well as the addictive disorder more difficult. In this presentation, we will focus on psychosocial treatments, including motivation enhancing strategies such as motivation enhancing strategies, the possibilities for using community reinforcement (family) approaches for this target group, as well as contingency management. Finally we will discuss the place, effects and ethics of involuntary treatment.



14:15 - 15:15 Parallel session III


3.1 Integrated treatment of dual disorders in The Netherlands: a qualitative study of client experiences

Anneke van Wamel, Research Associate, Trimbos-institute & Ankie Lempens, Senior projectmedewerker - Zorg & Participatie, Trimbos-institute

Many clients who suffer from severe mental health problems also struggle with alcohol and drug use. And although there seems to be a consensus in most European countries that integrated treatment models are best fitted to help these clients, none of these have strong evidence.

This is a qualitative study in which we conducted in-depth interviews with sixteen dual diagnosis clients with severe problems. We reflected on their situation at admission, the care they received in integrated treatment and their opinions on positive and negative elements. We also explored the changes and Improvements achieved through the use of integrated care care.

The interviews showed that the IDDT treatment had contributed to improvements in the areas of substance use, psychiatric well-being, housing, social relationships and daytime activities. In the analyses of the interviews we found three clusters of elements that clients indicated were the most helpful during their treatment and recovery process: trusting and meaningful relationship with the team, components of integrated treatment and organisation of care.

The findings emphasized the importance of working relationship in the treatment of complex and long-term problems. This has implications for the evaluation of these integrated treatment models.


3.2 Application of psychedelic drugs in psychiatric disorders

Tijmen Bostoen, psychiatrist and master of Pharmaceutical Sciences, ARQ Centrum '45

Psychedelic drugs show promising results in the treatment of psychiatric disorders. Esketamine has already been approved for treatment resistant depression. MDMA and Psilocybin combined with psychotherapy have been granted a ‘breakthrough therapy’ designation by the FDA for PTSD and depression.
This presentation examines the application of psychedelic drugs in psychiatric disorders that are currently under investigation. A brief scientific overview is given of the different substances such as MDMA, ketamine and psilocybin and the treatment of PTSD, addiction (nicotine, alcohol and cocaine) and depression. Different treatment models, pharmacotherapy versus psychedelic psychotherapy, will be explained. The psychotherapeutic framework within which these psychedelics are applied will also be discussed.

Mitchell, J. M., Bogenschutz, M., Lilienstein, A., Harrison, C., Kleiman, S., Parker-Guilbert, K., … & Doblin, R. (2021). MDMA-assisted therapy for severe PTSD: a randomized, double-blind, placebo-controlled phase 3 study. Nature Medicine, 27(6), 1025-1033
Horton, D. M., Morrison, B., & Schmidt, J. (2021). Systematized review of psychotherapeutic components of psilocybin-assisted psychotherapy. American Journal of Psychotherapy, 74(4), 140-149.
Ly, C., Greb, A. C., Cameron, L. P., Wong, J. M., Barragan, E. V., Wilson, P. C., … & Olson, D. E. (2018). Psychedelics promote structural and functional neural plasticity. Cell reports, 23(11), 3170-3182.
Krediet, E., Bostoen, T., Breeksema, J., van Schagen, A., Passie, T., & Vermetten, E. (2020). Reviewing the potential of psychedelics for the treatment of PTSD. International Journal of Neuropsychopharmacology, 23(6), 385-400.


3.3 Beyond addiction: a randomized controlled trial on the effectiveness of group schema therapy in patients with dual diagnosis

Sarah Brouwer, clinical psychologist, Brijder Kliniek, the Netherlands

The presence of substance use problems in combination with other mental illnesses (i.e. Dual Diagnosis) is associated with negative treatment outcomes. Research shows that integrated treatment for this population is recommended. However, until so far research has only focused on integrated treatment programs that deal with manifest symptoms and not on possible psychological origins, like youth trauma, parenting style and problems in emotion regulation.

The aim of this study is to compare the effectiveness of Group Schema Therapy (G-ST) and Group Cognitive Behavioral Therapy (G-CBT+MI) on symptoms, emotion regulation and addiction in DD outpatients. Moreover the effect of the severity of childhood maltreatment experiences, parenting style and degree of secure attachment on the effectiveness of G-ST will be investigated. At last, it will be examined whether security of attachment improves during therapy.

We will conduct a Randomized Controlled Trial (RCT), a pretest-midtest-posttest-3-month-12-month-follow-up-design, with two treatment conditions: the experimental condition (G-ST) and the control condition (G-CBT+MI). The study population will consist of 80 Dual Diagnosis patients between 18 and 65 years of age who are willing to participate in the study.

Patients assigned to the experimental condition will receive 30 weekly sessions (2 hours) of G-ST, plus 3 preparatory individual meetings. Patients in the control condition will also start with 3 individual meetings, followed by 30 weekly sessions (2 hours) of G-CBT+MI. At this moment, the study is in the data collection stage. 75 of the intended 106 subjects are being included.

In this workshop I will discuss our research design, how we adapted Schematherapy in order to pay attention to addiction and clinical observations until so far.


3.4 Oral esketamine for treatment-resistant depression: results of a randomized controlled trial and open-label treatment

Sanne Smith-Apeldoorn, Resident in Psychiatry and PhD Candidate and Dr. Jeanine Kamphuis, psychiatrist, University Medical Center Groningen

Background: (Es) ketamine can produce a rapid and large antidepressant response in patients with treatment-resistant depression (TRD). Oral administration of (es)ketamine has the greatest potential for accessibility and scalability. However, little is known of the efficacy, safety, and optimal frequency and dosing of oral (es)ketamine.

Objectives: To examine the antidepressant properties and safety of repeated oral esketamine in patients with TRD.

Methods: We conducted two studies to investigate repeated administration of oral esketamine in patients with TRD. The first study featured a triple-blind, randomized, placebo-controlled trial. 113 patients were randomly assigned to receive thrice daily oral esketamine (30 mg) or inactive placebo for 6 weeks, in addition to standard-of-care treatment. The second study featured a 6-weeks open-label treatment study. Patients with unipolar or bipolar TRD received oral esketamine twice weekly, with doses individually tailored.

Results: No difference in improvement in the HDRS total scores was observed in the thrice daily low-dose esketamine group compared with the placebo group (p=0.488). Between-group response rates were neither statistically different (p=0.446). However, after open-label treatment with twice weekly individualized doses, we observed a significant effect of treatment on the HDRS total score.

Conclusions: These preliminary findings indicate that a low dose of daily oral esketamine does not result in improvement in depressive symptoms among patients with TRD. On the other hand, individualized twice weekly dosing in an open-label design can induce significant improvement in depressive symptoms.


Guided tour CDP, Mangostraat 5

maximum 15 places available, based on pre-registration

Shuttle service to Mangostraat 5 at 13.15h, guided tour of 60 minutes, Shuttle service back at 15:00h. Lunch is arranged for at Mangostraat.


Coffee break

15:50 - 16:50 Parallel session IV


4.1 Self-harming behaviour and addiction: similarities, differences and possibilities for treatment using EMDR

Nieke Kool, PhD, sr. researcher, Fivoor, Parnassia Groep and Inholland University of Applied Sciences and Mariska van Kampen, clinical psychologist. Fivoor,the Netherlands

Is self-harming behaviour an addiction? Some say it is and some say it is not. In literature, differences but also similarities between these two kinds of behaviour are found. As self-harm is difficult to treat, there is a need for effective treatment. Therefore, we used the similarities between self-harm and addiction and investigated the “protocol imaginary execution of self-damaging behavior” as a potential treatment for self-harm. This protocol is based on EMDR. With this protocol, the patient is asked to imagine that he / she is performing the undesirable behaviour and at the same time a distracting task is offered, with which the working memory is double burdened. The purpose of this technique is to reduce the patient’s unwanted, harmful behaviour.

In our PIT-study (Protocol Imaginary execuTion of self-injury), we use a single-case experimental design, aiming to investigate whether there is a functional relationship between the treatment, the urge to self-harm and the frequency and seriousness of the self-harm.

In this workshop, we will present an overview of the similarities and differences between self-harm and addiction. Next, the PIT-study will be presented and the results will be discussed with the audience.


4.2 Money 4 medication, Contingency Management and the power of Nudge!

Ernst Noordraven, psychologist, Phd, Erasmus MC

In this workshop we will explain the concept of Contingency Management (CM) and Nudging within mental health care facilities. How can these methods effectively help to change people’s behaviour? Within our centre for Dual Diagnosis (CDP), patients with psychiatric illnesses and substance use disorders are treated using Integrated Dual Disorder Treatment (IDDT). This model is an evidence-based practice that improves quality of life for people by combining substance abuse services with mental health services. An important component is to stimulate behavioural changes. Therefore, the Money for Medication study was conducted within our clinic. Financial incentives (30 euro’s per month) were used for improving adherence in patients taking antipsychotic medication. In total, 169 patients were randomly assigned to the intervention group (n=84) or the control group (n=85). At 12 months, the mean adherence rate was higher in the intervention group (94.3%) than in the control group (80.3%), with an adjusted difference of 14.9% (95% CI 8.9–20.9%; p<0.0001). This difference was maintained throughout the 6 month follow-up period. Participants are invited to discuss the ethical and practical considerations of using CM interventions (such as financial incentives) in clinical practice and to what extend Nudging procedures can be used to change behaviour within patients with both psychiatric illnesses and substance use disorders.


4.3 Dual Disorder service delivery: Flexible and Stagewise treatment in community mental health teams

Koen Westen, Avans Hogeschool / CCAF, the Netherlands

Service delivery for people with a dual disorder: Flexible and stagewise treatment in community mental health teams. Dutch community mental health teams need to be able to deliver different services in a flexible and integrated manner for the total of their caseload and, in the same time, deliver these services stagewise per individual client. This workshop will provide an interactive explanation of the concepts of flexible and stagewise treatment for community mental health teams working with people with severe mental illness. An introduction will be given on the main topics and its practical implications. Based on a case study, stepwise treatment for dual disorders will be put into practice in order to use the knowledge gained to implement the method in daily practice.


4.4 Cannabis use, cannabis-induced psychosis and psychotic disorders. Findings from recent Scandinavian registry studies

Jørgen G. Bramness, Eline Borger Rognli, Solja Niemelä, Carsten Hjorthøj

Introduction: Jørgen G. Bramness

Cannabis use is increasingly acknowledged as a risk factor for schizophrenia. The causality is however debated. Genetic disposition may explain parts of the association, and while use and potency of cannabis has increased, we have up until recently not seen a parallel increase in the incidence of schizophrenia. This may be changing. Cannabis-induced psychosis (CIP) is diagnostically considered to be a type of a substance use disorder, but may also be seen as a condition linked to both cannabis use and to schizophrenia. A clearer understanding of the role of cannabis in the precipitation of schizophrenia is of great importance, and may have implications for the health care system and for policy makers.

Based on registry data from Sweden, Norway and Denmark, this symposium will present recent novel research on the association between cannabis and schizophrenia, and on CIP.

The results presented show an increase in cannabis-induced psychosis, and an increase in the proportion of cases of schizophrenia attributable to cannabis use disorder. Further, a substantial proportion of those with cannabis-induced psychosis are later diagnosed with schizophrenia. Persons with CIP differ from other first-episode psychosis patients in having less psychiatric comorbidity and better functional ability. These findings have important implications regarding legalization and control of use of cannabis, and also on how to view CIP.

Talk 1: Eline Borger Rognli

Cannabis-induced psychosis: incidence and transition to schizophrenia

Background: Cannabis use is increasingly viewed as a risk factor for schizophrenia. The incidence of CIP, and the transition rate from CIP to schizophrenia, is less investigated.

Methods: National patient registries from Denmark and Sweden for the years 2000 to 2016, and from Norway from 2010 to 2015, were used to estimate annual incidence of different types of SIP including CIP. In a separate Norwegian study, we estimated the cumulative hazard and the adjusted hazard ratios for transition from cannabis-induced psychosis to schizophrenia.

Results: The annual incidence rate of CIP increased from 2000 to 2016 with 113% in Denmark and with 265% in Sweden, and from 2010 to 2015 with 69% in Norway. The six-year cumulative hazard for transition from CIP to schizophrenia in Norway was 36% (95% CI 31.4-41.0). The risk of transition from SIP to schizophrenia increased with lower age in men and with more episodes of SIP in both genders.

Conclusion: The incidence of cannabis-induced psychosis has increased, and cannabis-induced psychosis is a considerable risk factor for later schizophrenia.

Talk 2: Solja Niemelä

Incident cannabis-induced psychosis compared to first-episode psychosis: findings from a national register-linkage study from Sweden

Background: Approximately 25-46% of persons with cannabis-induced psychosis (CIP) will subsequently receive a schizophrenia diagnosis. However, there is little previous research on differences between persons with incident CIP and persons with other types of first episode psychosis (FEP).

Methods; Incident substance-induced psychosis (SIP) cases aged 16 to 65 years (n=7320; CIP n=1185, 16.2% of all SIP cases) were identified from Swedish National Patient Register during the years 2006-2016. SIP cases were matched 1:1 (age, gender, calendar year) with incident FEP cases. Information on sociodemographic background, psychiatric disorders, and work-related factors during the proceeding two-year period before the incident SIP/FEP episode were linked from national registries. Comparisons were done using logistic regression analysis.

Results: Anxiety disorder, depression, eating disorder, mental retardation or autism spectrum disorders were less prevalent among CIP cases compared to FEP cases, being in line with other SIP types. Self-harm/suicide attempts were as prevalent as among FEP cases (8.4% vs 10.8%), but less prevalent than among any SIP (22.9%). Persons with CIP were more likely to be employed, and less likely to be on a disability pension compared to FEP cases.

Conclusion: Before the first psychotic episode, persons with CIP have less psychiatric comorbidity and better functional ability compared to other first-episode psychosis patients.

Talk 3: Carsten Hjorthøj

Prevention of cannabis may prevent a large proportion of schizophrenia cases – Danish register-based study

Background: Cannabis use and potency of cannabis has increased over the past years. If the association between cannabis and schizophrenia is causal, this should be reflected in an increase in the proportion of cases of schizophrenia being attributable to cannabis, the population attributable risk fraction (PAR%).

Methods: Nationwide, register-based cohort study of 7M+ individuals on the association and PAR% between cannabis use disorder and schizophrenia. We further investigated whether the association differed according to sex and age.

Results: The PAR% of cannabis use disorder schizophrenia increased from around 1995 (where the PAR% was relatively stable around 2%, with 95% CI of approximately 0.3% to either side) until reaching some stability between 6% and 8% (with 95% CI of approximately 0.5% to either side) since 2010. Preliminary, ongoing analyses indicated a much higher PAR% for young men, at upwards of 15% or even 20%-25% for younger men.


The proportion of cases of schizophrenia attributable to cannabis use disorder has increased three to four fold over the past two decades. In particular, almost a quarter of schizophrenia-cases among young men may be attributable to cannabis use disorder. This has important ramifications regarding legalization and control of use of cannabis.


4.5 Creating Evidence, Art Therapy experience on improving motivation for SUD treatment and feeling actor ship while creating an art piece

Marion Huijbregts and Martine Ruijter, Dutch Association of Art Therapy, The Netherlands

This workshop will start off with a small talk about the product we are writing about art therapy for adult clients with a substance use disorder, a product that can increase their motivation for treatment. We will also define what art therapy is and how it can be linked to motivational interviewing. This lecture presents the evidence, and argues what needs to be done to increase the evidence, on this topic and describes the clinical experiences in the Netherlands. Participants are given an exercise in which we use art materials and present it in the same way we would present it in therapy. Participants will experience what it is like to act in an art therapy session and what working with art materials can do for the motivation of the SUD population. After the exercise we will have time to talk about the experience and answer questions.


Closing ICDD 2022