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Kaar SJ, Nottage JF, Angelescu I, Marques TR, Howes OD. Gamma Oscillations and Potassium Channel Modulation in Schizophrenia: Targeting GABAergic Dysfunction. Clin EEG Neurosci 2024; 55:203-213. [PMID: 36591873 PMCID: PMC10851642 DOI: 10.1177/15500594221148643] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 12/08/2022] [Accepted: 12/12/2022] [Indexed: 01/03/2023]
Abstract
Impairments in gamma-aminobutyric acid (GABAergic) interneuron function lead to gamma power abnormalities and are thought to underlie symptoms in people with schizophrenia. Voltage-gated potassium 3.1 (Kv3.1) and 3.2 (Kv3.2) channels on GABAergic interneurons are critical to the generation of gamma oscillations suggesting that targeting Kv3.1/3.2 could augment GABAergic function and modulate gamma oscillation generation. Here, we studied the effect of a novel potassium Kv3.1/3.2 channel modulator, AUT00206, on resting state frontal gamma power in people with schizophrenia. We found a significant positive correlation between frontal resting gamma (35-45 Hz) power (n = 22, r = 0.613, P < .002) and positive and negative syndrome scale (PANSS) positive symptom severity. We also found a significant reduction in frontal gamma power (t13 = 3.635, P = .003) from baseline in patients who received AUT00206. This provides initial evidence that the Kv3.1/3.2 potassium channel modulator, AUT00206, may address gamma oscillation abnormalities in schizophrenia.
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Affiliation(s)
- Stephen J. Kaar
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- MRC London Institute of Medical Sciences, Hammersmith Hospital, London, UK
- Division of Psychology and Mental Health, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| | - Judith F. Nottage
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Ilinca Angelescu
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- Max Planck UCL Centre for Computational Psychiatry and Ageing Research London, London, UK
| | - Tiago Reis Marques
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- MRC London Institute of Medical Sciences, Hammersmith Hospital, London, UK
| | - Oliver D. Howes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- MRC London Institute of Medical Sciences, Hammersmith Hospital, London, UK
- Faculty of Medicine, Institute of Clinical Sciences (ICS), Imperial College London, London, UK
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Kaar SJ, Angelescu I, Nour MM, Marques TR, Sharman A, Sajjala A, Hutchison J, McGuire P, Large C, Howes OD. The effects of AUT00206, a novel Kv3.1/3.2 potassium channel modulator, on task-based reward system activation: a test of mechanism in schizophrenia. Psychopharmacology (Berl) 2022; 239:3313-3323. [PMID: 36094619 PMCID: PMC9481488 DOI: 10.1007/s00213-022-06216-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 08/16/2022] [Indexed: 11/28/2022]
Abstract
The pathophysiology of schizophrenia involves abnormal reward processing, thought to be due to disrupted striatal and dopaminergic function. Consistent with this hypothesis, functional magnetic resonance imaging (fMRI) studies using the monetary incentive delay (MID) task report hypoactivation in the striatum during reward anticipation in schizophrenia. Dopamine neuron activity is modulated by striatal GABAergic interneurons. GABAergic interneuron firing rates, in turn, are related to conductances in voltage-gated potassium 3.1 (Kv3.1) and 3.2 (Kv3.2) channels, suggesting that targeting Kv3.1/3.2 could augment striatal function during reward processing. Here, we studied the effect of a novel potassium Kv3.1/3.2 channel modulator, AUT00206, on striatal activation in patients with schizophrenia, using the MID task. Each participant completed the MID during fMRI scanning on two occasions: once at baseline, and again following either 4 weeks of AUT00206 or placebo treatment. We found a significant inverse relationship at baseline between symptom severity and reward anticipation-related neural activation in the right associative striatum (r = -0.461, p = 0.035). Following treatment with AUT00206, there was a significant increase in reward anticipation-related activation in the left associative striatum (t(13) = 4.23, peak-level p(FWE) < 0.05)), but no significant effect in the ventral striatum. This provides preliminary evidence that the Kv3.1/3.2 potassium channel modulator, AUT00206, may address reward-related striatal abnormalities in schizophrenia.
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Affiliation(s)
- Stephen J Kaar
- Institute of Psychiatry, Psychology & Neuroscience - King's College London, 16 De Crespigny Park, Camberwell, London, SE5 8AB, UK. .,Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, London, W12 0NN, UK. .,Division of Psychology and Mental Health, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, M13 9WL, UK. .,Greater Manchester Mental Health NHS Foundation Trust, Manchester, UK.
| | - Ilinca Angelescu
- Institute of Psychiatry, Psychology & Neuroscience - King's College London, 16 De Crespigny Park, Camberwell, London, SE5 8AB, UK.,Max Planck University College London Centre for Computational Psychiatry and Ageing Research, London, WC1B 5EH, UK
| | - Matthew M Nour
- Institute of Psychiatry, Psychology & Neuroscience - King's College London, 16 De Crespigny Park, Camberwell, London, SE5 8AB, UK.,Wellcome Trust Centre for Human Neuroimaging, University College London, London, WC1N 3AR, UK.,Department of Psychiatry, University of Oxford, Oxford, OX3 7JX, UK
| | - Tiago Reis Marques
- Institute of Psychiatry, Psychology & Neuroscience - King's College London, 16 De Crespigny Park, Camberwell, London, SE5 8AB, UK
| | - Alice Sharman
- Autifony Therapeutics Limited, Stevenage, SG1 2FX, UK
| | - Anil Sajjala
- Autifony Therapeutics Limited, Stevenage, SG1 2FX, UK
| | | | - Philip McGuire
- Institute of Psychiatry, Psychology & Neuroscience - King's College London, 16 De Crespigny Park, Camberwell, London, SE5 8AB, UK
| | - Charles Large
- Autifony Therapeutics Limited, Stevenage, SG1 2FX, UK
| | - Oliver D Howes
- Institute of Psychiatry, Psychology & Neuroscience - King's College London, 16 De Crespigny Park, Camberwell, London, SE5 8AB, UK.,Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, London, W12 0NN, UK.,South London and Maudsley NHS Foundation Trust, London, UK.,Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, W12 0NN, UK
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3
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Angelescu I, Kaar SJ, Marques TR, Borgan F, Veronesse M, Sharman A, Sajjala A, Deakin B, Hutchison J, Large C, Howes OD. The effect of AUT00206, a Kv3 potassium channel modulator, on dopamine synthesis capacity and the reliability of [ 18F]-FDOPA imaging in schizophrenia. J Psychopharmacol 2022; 36:1061-1069. [PMID: 36164687 PMCID: PMC9554157 DOI: 10.1177/02698811221122031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Current treatments for schizophrenia act directly on dopamine (DA) receptors but are ineffective for many patients, highlighting the need to develop new treatment approaches. Striatal DA dysfunction, indexed using [18F]-FDOPA imaging, is linked to the pathoetiology of schizophrenia. We evaluated the effect of a novel drug, AUT00206, a Kv3.1/3.2 potassium channel modulator, on dopaminergic function in schizophrenia and its relationship with symptom change. Additionally, we investigated the test-retest reliability of [18F]-FDOPA PET in schizophrenia to determine its potential as a biomarker for drug discovery. METHODS Twenty patients with schizophrenia received symptom measures and [18F]-FDOPA PET scans, before and after being randomised to AUT00206 or placebo groups for up to 28 days treatment. RESULTS AUT00206 had no significant effect on DA synthesis capacity. However, there was a correlation between reduction in striatal dopamine synthesis capacity (indexed as Kicer) and reduction in symptoms, in the AUT00206 group (r = 0.58, p = 0.03). This was not observed in the placebo group (r = -0.15, p = 0.75), although the placebo group may have been underpowered to detect an effect. The intraclass correlation coefficients of [18F]-FDOPA indices in the placebo group ranged from 0.83 to 0.93 across striatal regions. CONCLUSIONS The relationship between reduction in DA synthesis capacity and improvement in symptoms in the AUT00206 group provides evidence for a pharmacodynamic effect of the Kv3 channel modulator. The lack of a significant overall reduction in DA synthesis capacity in the AUT00206 group could be due to variability and the low number of subjects in this study. These findings support further investigation of Kv3 channel modulators for schizophrenia treatment. [18F]-FDOPA PET imaging showed very good test-retest reliability in patients with schizophrenia.
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Affiliation(s)
- Ilinca Angelescu
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.,Max Planck UCL Centre for Computational Psychiatry and Ageing Research, Institute of Neurology, London, UK
| | - Stephen J Kaar
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Tiago Reis Marques
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.,Faculty of Medicine, Institute of Clinical Sciences, Imperial College London, London, UK
| | - Faith Borgan
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Mattia Veronesse
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.,Department of Information Engineering, University of Padua, Padua, Italy
| | - Alice Sharman
- Autifony Therapeutics Limited, Stevenage Bioscience Catalyst, Stevenage, UK
| | - Anil Sajjala
- Autifony Therapeutics Limited, Stevenage Bioscience Catalyst, Stevenage, UK
| | - Bill Deakin
- Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, UK
| | - John Hutchison
- Autifony Therapeutics Limited, Stevenage Bioscience Catalyst, Stevenage, UK
| | - Charles Large
- Autifony Therapeutics Limited, Stevenage Bioscience Catalyst, Stevenage, UK
| | - Oliver D Howes
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.,Faculty of Medicine, Institute of Clinical Sciences, Imperial College London, London, UK
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Lobo MC, Whitehurst TS, Kaar SJ, Howes OD. New and emerging treatments for schizophrenia: a narrative review of their pharmacology, efficacy and side effect profile relative to established antipsychotics. Neurosci Biobehav Rev 2022; 132:324-361. [PMID: 34838528 DOI: 10.1016/j.neubiorev.2021.11.032] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 11/13/2021] [Accepted: 11/21/2021] [Indexed: 01/07/2023]
Abstract
Schizophrenia is associated with substantial unmet needs, highlighting the necessity for new treatments. This narrative review compares the pharmacology, clinical trial data and tolerability of novel medications to representative antipsychotics. Cariprazine, brexpiprazole and brilaroxazine are partial dopamine agonists effective in acute relapse. Lumateperone (serotonin and dopamine receptor antagonist) additionally benefits asocial and depressive symptoms. F17464 (D3 antagonist and 5-HT1A partial agonist) has one positive phase II study. Lu AF35700 (dopamine and serotonin receptor antagonist) was tested in treatment-resistance with no positive results. Pimavanserin, roluperidone, ulotaront and xanomeline do not act directly on the D2 receptor at clinical doses. Initial studies indicate pimavanserin and roluperidone improve negative symptoms. Ulotaront and xanomeline showed efficacy for positive and negative symptoms of schizophrenia in phase II trials. BI 409306, BI 425809 and MK-8189 target glutamatergic dysfunction in schizophrenia, though of these only BI 425809 showed efficacy. These medications largely have favourable cardiometabolic side-effect profiles. Overall, the novel pharmacology, clinical trial and tolerability data indicate these compounds are promising new additions to the therapeutic arsenal.
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Affiliation(s)
- Maria C Lobo
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; MRC London Institute of Medical Sciences, Hammersmith Hospital, London, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK; South London and Maudsley NHS Foundation Trust, Maudsley Hospital, London, UK.
| | - Thomas S Whitehurst
- MRC London Institute of Medical Sciences, Hammersmith Hospital, London, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK.
| | - Stephen J Kaar
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; South London and Maudsley NHS Foundation Trust, Maudsley Hospital, London, UK.
| | - Oliver D Howes
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK; South London and Maudsley NHS Foundation Trust, Maudsley Hospital, London, UK; H. Lundbeck UK, Ottiliavej 9, 2500, Valby, Denmark.
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Beck K, Arumuham A, Veronese M, Santangelo B, McGinnity CJ, Dunn J, McCutcheon RA, Kaar SJ, Singh N, Pillinger T, Borgan F, Stone J, Jauhar S, Sementa T, Turkheimer F, Hammers A, Howes OD. N-methyl-D-aspartate receptor availability in first-episode psychosis: a PET-MR brain imaging study. Transl Psychiatry 2021; 11:425. [PMID: 34385418 PMCID: PMC8361127 DOI: 10.1038/s41398-021-01540-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/03/2021] [Accepted: 06/28/2021] [Indexed: 02/07/2023] Open
Abstract
N-methyl-D-aspartate receptor (NMDAR) hypofunction is hypothesised to underlie psychosis but this has not been tested early in illness. To address this, we studied 40 volunteers (21 patients with first-episode psychosis and 19 matched healthy controls) using PET imaging with an NMDAR selective ligand, [18F]GE-179, that binds to the ketamine binding site to index its distribution volume ratio (DVR) and volume of distribution (VT). Hippocampal DVR, but not VT, was significantly lower in patients relative to controls (p = 0.02, Cohen's d = 0.81; p = 0.15, Cohen's d = 0.49), and negatively associated with total (rho = -0.47, p = 0.04), depressive (rho = -0.67, p = 0.002), and general symptom severity (rho = -0.74, p < 0.001). Exploratory analyses found no significant differences in other brain regions (anterior cingulate cortex, thalamus, striatum and temporal cortex). These findings are consistent with the NMDAR hypofunction hypothesis and identify the hippocampus as a key locus for relative NMDAR hypofunction, although further studies should test specificity and causality.
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Affiliation(s)
- Katherine Beck
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, De Crespigny Park, London, SE5 8AF, UK.
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, London, W12 0NN, UK.
- South London and Maudsley NHS Foundation Trust, London, UK.
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, W12 0NN, UK.
| | - Atheeshaan Arumuham
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, De Crespigny Park, London, SE5 8AF, UK
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, London, W12 0NN, UK
- South London and Maudsley NHS Foundation Trust, London, UK
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, W12 0NN, UK
| | - Mattia Veronese
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, De Crespigny Park, London, SE5 8AF, UK
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Barbara Santangelo
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, De Crespigny Park, London, SE5 8AF, UK
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Colm J McGinnity
- King's College London & Guy's and St Thomas' PET Centre, School of Biomedical Engineering & Imaging Sciences, King's College London, St Thomas' Hospital, London, SE1 7EH, UK
| | - Joel Dunn
- King's College London & Guy's and St Thomas' PET Centre, School of Biomedical Engineering & Imaging Sciences, King's College London, St Thomas' Hospital, London, SE1 7EH, UK
| | - Robert A McCutcheon
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, De Crespigny Park, London, SE5 8AF, UK
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, London, W12 0NN, UK
- South London and Maudsley NHS Foundation Trust, London, UK
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, W12 0NN, UK
| | - Stephen J Kaar
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, De Crespigny Park, London, SE5 8AF, UK
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, London, W12 0NN, UK
- South London and Maudsley NHS Foundation Trust, London, UK
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, W12 0NN, UK
| | - Nisha Singh
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Toby Pillinger
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, De Crespigny Park, London, SE5 8AF, UK
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, London, W12 0NN, UK
- South London and Maudsley NHS Foundation Trust, London, UK
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, W12 0NN, UK
| | - Faith Borgan
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, De Crespigny Park, London, SE5 8AF, UK
- COMPASS Pathways plc, London, UK
| | - James Stone
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, De Crespigny Park, London, SE5 8AF, UK
- South London and Maudsley NHS Foundation Trust, London, UK
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
- Brighton and Sussex Medical School, University of Sussex, Falmer, Brighton, UK
| | - Sameer Jauhar
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, De Crespigny Park, London, SE5 8AF, UK
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, London, W12 0NN, UK
- South London and Maudsley NHS Foundation Trust, London, UK
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, W12 0NN, UK
| | - Teresa Sementa
- King's College London & Guy's and St Thomas' PET Centre, School of Biomedical Engineering & Imaging Sciences, King's College London, St Thomas' Hospital, London, SE1 7EH, UK
| | - Federico Turkheimer
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Alexander Hammers
- King's College London & Guy's and St Thomas' PET Centre, School of Biomedical Engineering & Imaging Sciences, King's College London, St Thomas' Hospital, London, SE1 7EH, UK
| | - Oliver D Howes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, De Crespigny Park, London, SE5 8AF, UK.
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Hammersmith Hospital, London, W12 0NN, UK.
- South London and Maudsley NHS Foundation Trust, London, UK.
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, W12 0NN, UK.
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Kaar SJ, Gobjila C, Butler E, Henderson C, Howes OD. Making decisions about antipsychotics: a qualitative study of patient experience and the development of a decision aid. BMC Psychiatry 2019; 19:309. [PMID: 31646985 PMCID: PMC6806500 DOI: 10.1186/s12888-019-2304-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 09/23/2019] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Shared decision making is a widely accepted standard of patient-centred care that leads to improved clinical outcomes, yet it is commonly underutilised in the field of mental health. Furthermore, little is known regarding patient decision making around antipsychotic medication, which is often poorly adhered to. We aim to explore psychiatric patients' experiences of antipsychotic medication decision making in order to develop a patient decision aid to promote shared decision making. METHODS Focus groups were conducted with patients with chronic psychotic illnesses (n = 20) who had previously made a decision about taking or changing antipsychotic medication. Transcripts were coded and analysed for thematic content and continued until thematic saturation. These themes subsequently informed the development of a decision aid with the help of expert guidance. Further patient input was sought using the think aloud method (n = 3). RESULTS Twenty-three patients participated in the study. Thematic analysis revealed that 'adverse effects' was the most common theme identified by patients surrounding antipsychotic medication decision-making followed by 'mode and time of administration', 'symptom control' and 'autonomy'. The final decision aid is included to provoke further discussion and development of such aids. CONCLUSIONS Patients commonly report negative experiences of antipsychotic medication, in particular side-effects, which remain critical to future decision making around antipsychotic medication. Clinical encounters that increase patient knowledge and maximise autonomy in order to prevent early negative experiences with antipsychotic medication are likely to be beneficial.
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Affiliation(s)
- S J Kaar
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, PO63 De Crespigny Park, London, SE5 8AF, UK.
| | - C Gobjila
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, PO63 De Crespigny Park, London, SE5 8AF, UK
| | - E Butler
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, PO63 De Crespigny Park, London, SE5 8AF, UK
| | - C Henderson
- Health Service and Population Research, Psychological and Systems Sciences, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, London, SE5 8AZ, UK
| | - O D Howes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, PO63 De Crespigny Park, London, SE5 8AF, UK.,Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Imperial College, Hammersmith Hospital, London, UK
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Kaar SJ, Natesan S, McCutcheon R, Howes OD. Antipsychotics: Mechanisms underlying clinical response and side-effects and novel treatment approaches based on pathophysiology. Neuropharmacology 2019; 172:107704. [PMID: 31299229 DOI: 10.1016/j.neuropharm.2019.107704] [Citation(s) in RCA: 143] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 06/13/2019] [Accepted: 07/08/2019] [Indexed: 12/17/2022]
Abstract
Antipsychotic drugs are central to the treatment of schizophrenia and other psychotic disorders but are ineffective for some patients and associated with side-effects and nonadherence in others. We review the in vitro, pre-clinical, clinical and molecular imaging evidence on the mode of action of antipsychotics and their side-effects. This identifies the key role of striatal dopamine D2 receptor blockade for clinical response, but also for endocrine and motor side-effects, indicating a therapeutic window for D2 blockade. We consider how partial D2/3 receptor agonists fit within this framework, and the role of off-target effects of antipsychotics, particularly at serotonergic, histaminergic, cholinergic, and adrenergic receptors for efficacy and side-effects such as weight gain, sedation and dysphoria. We review the neurobiology of schizophrenia relevant to the mode of action of antipsychotics, and for the identification of new treatment targets. This shows elevated striatal dopamine synthesis and release capacity in dorsal regions of the striatum underlies the positive symptoms of psychosis and suggests reduced dopamine release in cortical regions contributes to cognitive and negative symptoms. Current drugs act downstream of the major dopamine abnormalities in schizophrenia, and potentially worsen cortical dopamine function. We consider new approaches including targeting dopamine synthesis and storage, autoreceptors, and trace amine receptors, and the cannabinoid, muscarinic, GABAergic and glutamatergic regulation of dopamine neurons, as well as post-synaptic modulation through phosphodiesterase inhibitors. Finally, we consider treatments for cognitive and negative symptoms such dopamine agonists, nicotinic agents and AMPA modulators before discussing immunological approaches which may be disease modifying. This article is part of the issue entitled 'Special Issue on Antipsychotics'.
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Affiliation(s)
- Stephen J Kaar
- Department of Psychosis Studies, 5th Floor, Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King's College London, PO63 De Crespigny Park, London, SE5 8AF, United Kingdom.
| | - Sridhar Natesan
- Department of Psychosis Studies, 5th Floor, Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King's College London, PO63 De Crespigny Park, London, SE5 8AF, United Kingdom
| | - Robert McCutcheon
- Department of Psychosis Studies, 5th Floor, Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King's College London, PO63 De Crespigny Park, London, SE5 8AF, United Kingdom
| | - Oliver D Howes
- Department of Psychosis Studies, 5th Floor, Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King's College London, PO63 De Crespigny Park, London, SE5 8AF, United Kingdom.
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8
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Affiliation(s)
- Oliver H Howes
- Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
- Medical Research Council London Institute of Medical Sciences, London, UK
- Institute of Clinical Sciences, Imperial College, Hammersmith Hospital Campus, London, UK
| | - Stephen J Kaar
- Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
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Kaar SJ, Ferris J, Waldron J, Devaney M, Ramsey J, Winstock AR. Up: The rise of nitrous oxide abuse. An international survey of contemporary nitrous oxide use. J Psychopharmacol 2016; 30:395-401. [PMID: 26912510 DOI: 10.1177/0269881116632375] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In recent years the recreational use of inhaled nitrous oxide gas (N2O) is becoming increasingly popular, yet little is known about the characteristics of its users or the effects they experience. This paper presents original research from the 2014 Global Drug Survey (GDS) (n=74,864). GDS runs the largest survey of recreational drug use in the world. The findings confirm N2O as a very common drug of use, in particular in the UK and US (38.6% and 29.4% lifetime prevalence). In the UK N2O was reported to be the eighth most commonly used substance. N2O was generally consumed via gas-filled balloons, at festivals and clubs where use of other substances was common. The vast majority of users use infrequently, and their use is not associated with significant harm. However, there appears to be a subpopulation of heavy users who may be using in a dependent pattern. Analysis of last year N2O users (n=4883), confirms that N2O is associated with hallucinations and confusion (which may be the desired effects) and persistent numbness and accidental injury (27.8%, 23.9%, 4.3% and 1.2% of last year users, respectively). Accidental injury is associated with the highest number of 'hits' per session, suggesting a dose-response relationship. The presence of significant harm is discussed in the light of public education on the risks of N2O use and harm-reduction strategies appropriate to N2O use. Further work needs to be completed to confirm the presence of persistent neurological symptoms in recreational users.
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Affiliation(s)
- Stephen J Kaar
- Addiction CAG, South London and Maudsley NHS Trust, London, UK Global Drug Survey, London, UK
| | - Jason Ferris
- Institute for Social Science Research, The University of Queensland, Brisbane, QLD, Australia ARC Centre of Excellence for Children and Families over the Life Course, Institute for Social Science Research, The University of Queensland, Brisbane, QLD, Australia
| | | | - Madonna Devaney
- Institute for Social Science Research, The University of Queensland, Brisbane, QLD, Australia
| | - John Ramsey
- Global Drug Survey, London, UK TICTAC Communications Ltd, St George's, University of London, London, UK
| | - Adam R Winstock
- Addiction CAG, South London and Maudsley NHS Trust, London, UK Global Drug Survey, London, UK
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10
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Affiliation(s)
- C Kan
- Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience
| | - S J Kaar
- General Adult Psychiatry, South London and Maudsley NHS Foundation Trust
| | - M Eisa
- General Adult Psychiatry, Barnet, Enfield and Haringey NHS Trust
| | - L Jones
- General Adult Psychiatry, South London and Maudsley NHS Foundation Trust
| | - J Beckett
- General Adult Psychiatry, South London and Maudsley NHS Foundation Trust
| | - O Mustafa
- Department of Diabetes, King's College Hospital, King's Health Partners, London, UK
| | - K Ismail
- Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience
- Department of Diabetes, King's College Hospital, King's Health Partners, London, UK
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11
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Kaar SJ, Gao CX, Lloyd B, Smith K, Lubman DI. Trends in cannabis-related ambulance presentations from 2000 to 2013 in Melbourne, Australia. Drug Alcohol Depend 2015; 155:24-30. [PMID: 26361711 DOI: 10.1016/j.drugalcdep.2015.08.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 07/28/2015] [Accepted: 08/25/2015] [Indexed: 01/14/2023]
Abstract
AIMS The current burden of cannabis-related presentations to emergency health services is largely unknown. This paper presents data collected over a 13-year period in metropolitan Melbourne, Australia as part of the Ambo Project, a unique surveillance system that analyses and codes paramedic records for drug-related trends and harms. METHODS Cannabis-related ambulance attendances involving 15-59 year olds in metropolitan Melbourne were analysed retrospectively from 2000 to 2013 (n=10,531). Trends and attendance characteristics were compared among cannabis only (CO)-, cannabis and alcohol (CA)- and cannabis with polydrug use (CP)-related attendances. Changes in alcohol and drug involvements in cannabis-related attendances were explored. RESULTS Rates of cannabis-related ambulance attendances increased significantly over the study period. Increasing rate of attendances per 100,000 population per year changed from 0.6 (2000-2010) to 5.5 (2010-2013). This sharp change was driven by CO- and CP-related attendances (rate of CA-related attendance increased steadily). The highest increasing rate (15.6) was for CO-related attendances among 15-29 years old males (2010-2013). Crystal methamphetamine became the most common illicit co-intoxicant amongst cannabis presentations in 2013. CONCLUSIONS Relative to the total drug-related burden on ambulance services, cannabis-related presentations appear to be a small but significant and increasing problem. Significant changes in trends across other drug involvement and demographic subgroups suggest a possible shift in the cannabis using population and/or a change in using behaviours. Public health strategies should raise awareness of the increased risk posed by cannabis polydrug use and high attendance subpopulations should be determined.
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Affiliation(s)
- Stephen J Kaar
- Turning Point, Eastern Health, 54-62 Gertrude Street, Fitzroy, Vic 3065, Australia; South London and Maudsley NHS Trust, Addictions Clinical Academic Group, Lorraine Hewitt House, 12-14 Brighton Terrace, Brixton, London SW9 8DG, United Kingdom
| | - Caroline X Gao
- Turning Point, Eastern Health, 54-62 Gertrude Street, Fitzroy, Vic 3065, Australia; Eastern Health Clinical School, Monash University, Level 2, 5 Arnold Street, Box Hill, Vic 3128, Australia
| | - Belinda Lloyd
- Turning Point, Eastern Health, 54-62 Gertrude Street, Fitzroy, Vic 3065, Australia; Eastern Health Clinical School, Monash University, Level 2, 5 Arnold Street, Box Hill, Vic 3128, Australia
| | - Karen Smith
- Ambulance Victoria, PO Box 2000, Doncaster, Vic 3108, Australia; Department of Epidemiology and Preventive Medicine, Monash University, The Alfred Centre, 99 Commercial Road, Melbourne, Vic 3004, Australia
| | - Dan I Lubman
- Turning Point, Eastern Health, 54-62 Gertrude Street, Fitzroy, Vic 3065, Australia; Eastern Health Clinical School, Monash University, Level 2, 5 Arnold Street, Box Hill, Vic 3128, Australia.
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