Observational studyThe British journal of psychiatry : the journal of mental science2015
Response to clozapine in a clinically identifiable subtype of schizophrenia.
Open access · bronzeAbstract readComparative StudyObservational Study
In one paragraph
Observational study in The British journal of psychiatry : the journal of mental science, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 40 papers, 3 of them syntheses that pooled it.
0numbers the graph read from it
0cells of the map it votes in
40citing papers in PubMed, 3 pooled it
5.3field-weighted citation impact, top 4% of its field
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
40 citing papers in PubMed, 3 syntheses or guidelines pooled it, 75 citations in OpenAlex.
- Effectiveness and side effects of psychopharmacotherapy in individuals with 22q11.2 deletion syndrome with comorbid psychiatric disorders: a systematic review.European child & adolescent psychiatry · 2020Pooled it
- Adverse effects of antipsychotic medication in patients with 22q11.2 deletion syndrome: A systematic review.American journal of medical genetics. Part A · 2019Pooled it
- Clozapine for psychotic disorders in adults with intellectual disabilities.The Cochrane database of systematic reviews · 2015Pooled it
- Following the Action of Atypical Antipsychotic Clozapine and Possible Prediction of Treatment Response in Schizophrenia.Life (Basel, Switzerland) · 2025Review
- Psychopharmacology in children with genetic disorders of epigenetic and chromatin regulation.Journal of neurodevelopmental disorders · 2025Article
- An integrated clinical approach to children at genetic risk for neurodevelopmental and psychiatric conditions: interdisciplinary collaboration and research infrastructure.Journal of neurodevelopmental disorders · 2024Article
- Increased Prevalence of Rare Copy Number Variants in Treatment-Resistant Psychosis.Schizophrenia bulletin · 2023Article
- A case study of the utilization of clozapine treatment for treatment-resistant schizophrenia associated with 22q11.2 deletion syndrome.Neuropsychopharmacology reports · 2023Article
- Barriers to genetic testing in clinical psychiatry and ways to overcome them: from clinicians' attitudes to sociocultural differences between patients across the globe.Translational psychiatry · 2022Review
- Neurological manifestation of 22q11.2 deletion syndrome.Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology · 2022Review
- Clinical evaluation of patients with a neuropsychiatric risk copy number variant.Current opinion in genetics & development · 2021Review
- Clozapine-induced gastroesophageal rumination in 22q11.2 Deletion Syndrome. A case report on gastroesophageal side effects management without renouncing clozapine's effectiveness.Clinical case reports · 2021Article
- Need for psychiatric phenotyping in patients with rare genetic disorders.European child & adolescent psychiatry · 2021Article
- Towards Precision Medicine in Psychosis: Benefits and Challenges of Multimodal Multicenter Studies-PSYSCAN: Translating Neuroimaging Findings From Research into Clinical Practice.Schizophrenia bulletin · 2020Article
- Cognition- and circuit-based dysfunction in a mouse model of 22q11.2 microdeletion syndrome: effects of stress.Translational psychiatry · 2020Article
- Polygenic Risk Scores for Subtyping of Schizophrenia.Schizophrenia research and treatment · 2020Article
- Association of a functional Claudin-5 variant with schizophrenia in female patients with the 22q11.2 deletion syndrome.Schizophrenia research · 2020Article
- All-cause mortality and survival in adults with 22q11.2 deletion syndrome.Genetics in medicine : official journal of the American College of Medical Genetics · 2019Article
- 22q11.2 Deletion Syndrome-Associated Parkinson's Disease.Movement disorders clinical practice · 2019Review
- Clozapine-induced myocarditis in an adolescent male with DiGeorge Syndrome.The mental health clinician · 2018Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors at 2 institutions in 1 country.
Nancy J ButcherNancy J. Butcher, MSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Institute of Medical Science, University of Toronto, Toronto; Wai Lun Alan Fung, MD, ScD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto General Research Institute, University Health Network, Toronto, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome and Department of Psychiatry, University Health Network and Department of Psychiatry, University of Toronto, Toronto; Laura Fitzpatrick, Alina Guna, BSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto; Danielle M. Andrade, MD, MSc, FRCPC, Division of Neurology, Department of Medicine, University of Toronto, Toronto; Anthony E. Lang, MD, FRCPC, Institute of Medical Science, University of Toronto, Division of Neurology, Department of Medicine, University of Toronto, Tanz Centre for Research in Neurodegenerative Diseases, Department of Medicine, University of Toronto, Toronto Western Hospital Research Institute, University Health Network and Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, Toronto; Eva W. C. Chow, MD, MPH, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Department of Psychiatry, University of Toronto, Toronto; Anne S. Bassett, MD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Institute of Medical Science, University of Toronto, Toronto General Research Institute, University Health Network, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome, Department of Medicine and Department of Psychiatry, University Health Network, Department of Psychiatry, University of Toronto, Ontario, Canada.
Wai Lun Alan FungNancy J. Butcher, MSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Institute of Medical Science, University of Toronto, Toronto; Wai Lun Alan Fung, MD, ScD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto General Research Institute, University Health Network, Toronto, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome and Department of Psychiatry, University Health Network and Department of Psychiatry, University of Toronto, Toronto; Laura Fitzpatrick, Alina Guna, BSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto; Danielle M. Andrade, MD, MSc, FRCPC, Division of Neurology, Department of Medicine, University of Toronto, Toronto; Anthony E. Lang, MD, FRCPC, Institute of Medical Science, University of Toronto, Division of Neurology, Department of Medicine, University of Toronto, Tanz Centre for Research in Neurodegenerative Diseases, Department of Medicine, University of Toronto, Toronto Western Hospital Research Institute, University Health Network and Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, Toronto; Eva W. C. Chow, MD, MPH, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Department of Psychiatry, University of Toronto, Toronto; Anne S. Bassett, MD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Institute of Medical Science, University of Toronto, Toronto General Research Institute, University Health Network, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome, Department of Medicine and Department of Psychiatry, University Health Network, Department of Psychiatry, University of Toronto, Ontario, Canada.
Laura FitzpatrickNancy J. Butcher, MSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Institute of Medical Science, University of Toronto, Toronto; Wai Lun Alan Fung, MD, ScD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto General Research Institute, University Health Network, Toronto, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome and Department of Psychiatry, University Health Network and Department of Psychiatry, University of Toronto, Toronto; Laura Fitzpatrick, Alina Guna, BSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto; Danielle M. Andrade, MD, MSc, FRCPC, Division of Neurology, Department of Medicine, University of Toronto, Toronto; Anthony E. Lang, MD, FRCPC, Institute of Medical Science, University of Toronto, Division of Neurology, Department of Medicine, University of Toronto, Tanz Centre for Research in Neurodegenerative Diseases, Department of Medicine, University of Toronto, Toronto Western Hospital Research Institute, University Health Network and Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, Toronto; Eva W. C. Chow, MD, MPH, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Department of Psychiatry, University of Toronto, Toronto; Anne S. Bassett, MD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Institute of Medical Science, University of Toronto, Toronto General Research Institute, University Health Network, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome, Department of Medicine and Department of Psychiatry, University Health Network, Department of Psychiatry, University of Toronto, Ontario, Canada.
Alina GunaNancy J. Butcher, MSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Institute of Medical Science, University of Toronto, Toronto; Wai Lun Alan Fung, MD, ScD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto General Research Institute, University Health Network, Toronto, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome and Department of Psychiatry, University Health Network and Department of Psychiatry, University of Toronto, Toronto; Laura Fitzpatrick, Alina Guna, BSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto; Danielle M. Andrade, MD, MSc, FRCPC, Division of Neurology, Department of Medicine, University of Toronto, Toronto; Anthony E. Lang, MD, FRCPC, Institute of Medical Science, University of Toronto, Division of Neurology, Department of Medicine, University of Toronto, Tanz Centre for Research in Neurodegenerative Diseases, Department of Medicine, University of Toronto, Toronto Western Hospital Research Institute, University Health Network and Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, Toronto; Eva W. C. Chow, MD, MPH, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Department of Psychiatry, University of Toronto, Toronto; Anne S. Bassett, MD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Institute of Medical Science, University of Toronto, Toronto General Research Institute, University Health Network, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome, Department of Medicine and Department of Psychiatry, University Health Network, Department of Psychiatry, University of Toronto, Ontario, Canada.
Danielle M AndradeNancy J. Butcher, MSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Institute of Medical Science, University of Toronto, Toronto; Wai Lun Alan Fung, MD, ScD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto General Research Institute, University Health Network, Toronto, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome and Department of Psychiatry, University Health Network and Department of Psychiatry, University of Toronto, Toronto; Laura Fitzpatrick, Alina Guna, BSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto; Danielle M. Andrade, MD, MSc, FRCPC, Division of Neurology, Department of Medicine, University of Toronto, Toronto; Anthony E. Lang, MD, FRCPC, Institute of Medical Science, University of Toronto, Division of Neurology, Department of Medicine, University of Toronto, Tanz Centre for Research in Neurodegenerative Diseases, Department of Medicine, University of Toronto, Toronto Western Hospital Research Institute, University Health Network and Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, Toronto; Eva W. C. Chow, MD, MPH, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Department of Psychiatry, University of Toronto, Toronto; Anne S. Bassett, MD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Institute of Medical Science, University of Toronto, Toronto General Research Institute, University Health Network, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome, Department of Medicine and Department of Psychiatry, University Health Network, Department of Psychiatry, University of Toronto, Ontario, Canada.
Anthony E LangNancy J. Butcher, MSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Institute of Medical Science, University of Toronto, Toronto; Wai Lun Alan Fung, MD, ScD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto General Research Institute, University Health Network, Toronto, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome and Department of Psychiatry, University Health Network and Department of Psychiatry, University of Toronto, Toronto; Laura Fitzpatrick, Alina Guna, BSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto; Danielle M. Andrade, MD, MSc, FRCPC, Division of Neurology, Department of Medicine, University of Toronto, Toronto; Anthony E. Lang, MD, FRCPC, Institute of Medical Science, University of Toronto, Division of Neurology, Department of Medicine, University of Toronto, Tanz Centre for Research in Neurodegenerative Diseases, Department of Medicine, University of Toronto, Toronto Western Hospital Research Institute, University Health Network and Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, Toronto; Eva W. C. Chow, MD, MPH, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Department of Psychiatry, University of Toronto, Toronto; Anne S. Bassett, MD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Institute of Medical Science, University of Toronto, Toronto General Research Institute, University Health Network, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome, Department of Medicine and Department of Psychiatry, University Health Network, Department of Psychiatry, University of Toronto, Ontario, Canada.
Eva W C ChowNancy J. Butcher, MSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Institute of Medical Science, University of Toronto, Toronto; Wai Lun Alan Fung, MD, ScD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto General Research Institute, University Health Network, Toronto, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome and Department of Psychiatry, University Health Network and Department of Psychiatry, University of Toronto, Toronto; Laura Fitzpatrick, Alina Guna, BSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto; Danielle M. Andrade, MD, MSc, FRCPC, Division of Neurology, Department of Medicine, University of Toronto, Toronto; Anthony E. Lang, MD, FRCPC, Institute of Medical Science, University of Toronto, Division of Neurology, Department of Medicine, University of Toronto, Tanz Centre for Research in Neurodegenerative Diseases, Department of Medicine, University of Toronto, Toronto Western Hospital Research Institute, University Health Network and Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, Toronto; Eva W. C. Chow, MD, MPH, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Department of Psychiatry, University of Toronto, Toronto; Anne S. Bassett, MD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Institute of Medical Science, University of Toronto, Toronto General Research Institute, University Health Network, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome, Department of Medicine and Department of Psychiatry, University Health Network, Department of Psychiatry, University of Toronto, Ontario, Canada.
Anne S BassettNancy J. Butcher, MSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Institute of Medical Science, University of Toronto, Toronto; Wai Lun Alan Fung, MD, ScD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto General Research Institute, University Health Network, Toronto, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome and Department of Psychiatry, University Health Network and Department of Psychiatry, University of Toronto, Toronto; Laura Fitzpatrick, Alina Guna, BSc, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto; Danielle M. Andrade, MD, MSc, FRCPC, Division of Neurology, Department of Medicine, University of Toronto, Toronto; Anthony E. Lang, MD, FRCPC, Institute of Medical Science, University of Toronto, Division of Neurology, Department of Medicine, University of Toronto, Tanz Centre for Research in Neurodegenerative Diseases, Department of Medicine, University of Toronto, Toronto Western Hospital Research Institute, University Health Network and Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, Toronto; Eva W. C. Chow, MD, MPH, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health and Department of Psychiatry, University of Toronto, Toronto; Anne S. Bassett, MD, FRCPC, Clinical Genetics Research Program, Centre for Addiction and Mental Health, Institute of Medical Science, University of Toronto, Toronto General Research Institute, University Health Network, The Dalglish Family Hearts and Minds Clinic for Adults with 22q11.2 Deletion Syndrome, Department of Medicine and Department of Psychiatry, University Health Network, Department of Psychiatry, University of Toronto, Ontario, Canada.
Centre for Addiction and Mental Health · CAUniversity Health Network · CA
Funding
CIHR 111238-2CIHR MOP111238CIHR MOP97800
Abstract
backgroundGenetic testing in psychiatry promises to improve patient care through advances in personalised medicine. However, there are few clinically relevant examples.
aimsTo determine whether patients with a well-established genetic subtype of schizophrenia show a different response profile to the antipsychotic clozapine than those with idiopathic schizophrenia.
methodWe retrospectively studied the long-term safety and efficacy of clozapine in 40 adults with schizophrenia, half with a 22q11.2 deletion (22q11.2DS group) and half matched for age and clinical severity but molecularly confirmed to have no pathogenic copy number variant (idiopathic group).
resultsBoth groups showed similar clinical improvement and significant reductions in hospitalisations, achieved at a lower median dose for those in the 22q11.2DS group. Most common side-effects were similarly prevalent between the two groups, however, half of the 22q11.2DS group experienced at least one rare serious adverse event compared with none of the idiopathic group. Many were successfully retried on clozapine.
conclusionsIndividuals with 22q11.2DS-schizophrenia respond as well to clozapine treatment as those with other forms of schizophrenia, but may represent a disproportionate number of those with serious adverse events, primarily seizures. Lower doses and prophylactic (for example anticonvulsant) management strategies can help ameliorate side-effect risks. This first systematic evaluation of antipsychotic response in a genetic subtype of schizophrenia provides a proof-of-principle for personalised medicine and supports the utility of clinical genetic testing in schizophrenia.
Indexed as
AdultAntipsychotic AgentsClozapineDiGeorge SyndromeDose-Response Relationship, DrugDrug SubstitutionFemaleHospitalizationHumansMaleMiddle AgedMyocarditisNeutropeniaSchizophreniaSeizuresTreatment OutcomeAntipsychotic AgentsClozapine
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