A systematic review of interventions in the early course of bipolar disorder I or II: a report of the International Society for Bipolar Disorders Taskforce on early intervention.

"Declarations Ethics approval and consent to participateNot applicable. Consent for publicationNot applicable. Competing interestsMB is supported by a NHMRC Senior Principal Research Fellowship (1156072). MB has received Grant/Research Support from the NIH, Cooperative Research Centre, Simons Autism Foundation, Cancer Council of Victoria, Stanley Medical Research Foundation, Medical Benefits Fund, National Health and Medical Research Council, Medical Research Futures Fund, Beyond Blue, Rotary Health, A2 milk company, Meat and Livestock Board, Woolworths, Avant and the Harry Windsor Foundation, has been a speaker for Abbot, Astra Zeneca, Janssen and Janssen, Lundbeck and Merck and served as a consultant to Allergan, Astra Zeneca, Bioadvantex, Bionomics, Collaborative Medicinal Development, Eisai, Janssen and Janssen, Lundbeck Merck, Pfizer and Servier—all unrelated to this work. LVK has within recent three years been a consultant for Teva and Lundbeck. SJ has received speaker fees for educational talks given for Jannsen, Lundbeck and Sunovian. MT was an employee of Lilly (1997 to 2008) and has received honoraria from or consulted for Abbott, Abvvie, AstraZeneca, Alkermes, Allergan, Bristol Myers Squibb, GlaxoSmithKline, Lilly, Johnson & Johnson, Otsuka, Merck, Gedeon Richter Plc, Sunovion, Intracellular Therapies, Forest, Roche, Elan, Lundbeck, Teva, Pamlab, Minerva, Neurocrine, Pfizer, and Wiley Publishing; his spouse was a full time employee at Lilly (1998–2013). DJM receives research support from the NIMH, the Danny Alberts Foundation, Attias Family Foundation, Carl and Roberta Deutsch Foundation, Kayne Family Foundation, AIM for Mental Health, and Max Gray Fund; and book royalties from Guilford Press and John Wiley and Sons. MAF receives royalties from American Psychiatric Publishing and Guilford Press, research support from Janssen, and an editorial stipend from the Society of Clinical Child and Adolescent Psychology. AY has been paid for lectures and advisory boards for the following companies with drugs used in affective and related disorders: Astrazenaca, Eli Lilly, Lundbeck, Sunovion, Servier, Livanova, Janssen, Allegan, Bionomics, Sumitomo Dainippon Pharma, COMPASS, Sage, Novartis. He has been a consultant for Johnson & Johnson and Livanova. He has received honoraria for attending advisory boards and presenting talks at meetings organised by LivaNova, and has been the principal Investigator in the Restore-Life VNS registry study funded by LivaNova. He has also been a principal or chief Investigator on ESKETINTRD3004, Novartis MDD study MIJ821A12201, and trials on psilocybin. He has received grant funding (past and present) from: NIMH (USA); CIHR (Canada); NARSAD (USA); Stanley Medical Research Institute (USA); MRC (UK); Wellcome Trust (UK); Royal College of Physicians (Edin); BMA (UK); UBC-VGH Foundation (Canada); WEDC (Canada); CCS Depression Research Fund (Canada); MSFHR (Canada); NIHR (UK). Janssen (UK). He has no shareholdings in pharmaceutical companies. Professor Young’s independent research is funded by the National Institute for Health Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR, or the Department of Health. AR is supported by an NHMRC (Australia) Early Career Fellowship. The other authors have no conflicts to declare. Competing interests MB is supported by a NHMRC Senior Principal Research Fellowship (1156072). MB has received Grant/Research Support from the NIH, Cooperative Research Centre, Simons Autism Foundation, Cancer Council of Victoria, Stanley Medical Research Foundation, Medical Benefits Fund, National Health and Medical Research Council, Medical Research Futures Fund, Beyond Blue, Rotary Health, A2 milk company, Meat and Livestock Board, Woolworths, Avant and the Harry Windsor Foundation, has been a speaker for Abbot, Astra Zeneca, Janssen and Janssen, Lundbeck and Merck and served as a consultant to Allergan, Astra Zeneca, Bioadvantex, Bionomics, Collaborative Medicinal Development, Eisai, Janssen and Janssen, Lundbeck Merck, Pfizer and Servier—all unrelated to this work. LVK has within recent three years been a consultant for Teva and Lundbeck. SJ has received speaker fees for educational talks given for Jannsen, Lundbeck and Sunovian. MT was an employee of Lilly (1997 to 2008) and has received honoraria from or consulted for Abbott, Abvvie, AstraZeneca, Alkermes, Allergan, Bristol Myers Squibb, GlaxoSmithKline, Lilly, Johnson & Johnson, Otsuka, Merck, Gedeon Richter Plc, Sunovion, Intracellular Therapies, Forest, Roche, Elan, Lundbeck, Teva, Pamlab, Minerva, Neurocrine, Pfizer, and Wiley Publishing; his spouse was a full time employee at Lilly (1998–2013). DJM receives research support from the NIMH, the Danny Alberts Foundation, Attias Family Foundation, Carl and Roberta Deutsch Foundation, Kayne Family Foundation, AIM for Mental Health, and Max Gray Fund; and book royalties from Guilford Press and John Wiley and Sons. MAF receives royalties from American Psychiatric Publishing and Guilford Press, research support from Janssen, and an editorial stipend from the Society of Clinical Child and Adolescent Psychology. AY has been paid for lectures and advisory boards for the following companies with drugs used in affective and related disorders: Astrazenaca, Eli Lilly, Lundbeck, Sunovion, Servier, Livanova, Janssen, Allegan, Bionomics, Sumitomo Dainippon Pharma, COMPASS, Sage, Novartis. He has been a consultant for Johnson & Johnson and Livanova. He has received honoraria for attending advisory boards and presenting talks at meetings organised by LivaNova, and has been the principal Investigator in the Restore-Life VNS registry study funded by LivaNova. He has also been a principal or chief Investigator on ESKETINTRD3004, Novartis MDD study MIJ821A12201, and trials on psilocybin. He has received grant funding (past and present) from: NIMH (USA); CIHR (Canada); NARSAD (USA); Stanley Medical Research Institute (USA); MRC (UK); Wellcome Trust (UK); Royal College of Physicians (Edin); BMA (UK); UBC-VGH Foundation (Canada); WEDC (Canada); CCS Depression Research Fund (Canada); MSFHR (Canada); NIHR (UK). Janssen (UK). He has no shareholdings in pharmaceutical companies. Professor Young’s independent research is funded by the National Institute for Health Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR, or the Department of Health. AR is supported by an NHMRC (Australia) Early Career Fellowship. The other authors have no conflicts to declare."

"Funding This project did not have specific funding."

"The study followed a peer-reviewed protocol (registered on the Prospero website: CRD42020195956) and adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA, 2020 (Page et al. ), Additional file : Table S2) and Synthesis Without Meta-Analysis (SWIM (Campbell et al. )) guidelines."