1. Barkus E, Lewis S (2008) Schizotypy and psychosis-like experiences from recreational cannabis in a non-clinical sample. Psychol Med 38:1267–1276

2. Gage SH, Hickman M, Zammit S (2016) Association between cannabis and psychosis: epidemiologic evidence. Biol Psychiatry 79:549–556

3. Martin-Santos R, Crippa JA, Batalla A et al (2012) Acute effects of a single, oral dose of d9-tetrahydrocannabinol (THC) and cannabidiol (CBD) administration in healthy volunteers. Curr Pharm Des 18:4966–4979

4. Mechoulam R, Hanus LO, Pertwee R et al (2014) Early phytocannabinoid chemistry to endocannabinoids and beyond. Nat Rev Neurosci 15:757–764

5. Gage SH, Zammit S, Hickman M (2013) Stronger evidence is needed before accepting that cannabis plays an important role in the aetiology of schizophrenia in the population. F1000 Med Rep 5:2

6. Hill M (2015) Perspective: be clear about the real risks. Nature 525:S14

7. Ksir C, Hart CL (2016) Cannabis and psychosis: a critical overview of the relationship. Curr Psychiatry Rep 18:12

8. Minozzi S, Davoli M, Bargagli AM et al (2010) An overview of systematic reviews on cannabis and psychosis: discussing apparently conflicting results. Drug Alcohol Rev 29:304–317

9. Di Forti M, Quattrone D, Freeman TP et al (2019) The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicentre case–control study. Lancet Psychiatry 6:427–436

10. Schoeler T, Monk A, Sami MB et al (2016) Continued versus discontinued cannabis use in patients with psychosis: a systematic review and meta-analysis. Lancet Psychiatry 3:215–225

11. Burns JK (2013) Pathways from cannabis to psychosis: a review of the evidence. Front Psychiatry 4:128

12. D’souza DC, Sewell RA, Ranganathan M (2009) Cannabis and psychosis/schizophrenia: human studies. Eur Arch Psychiatry Clin Neurosci 259:413–431

13. Bersani G, Orlandi V, Kotzalidis GD et al (2002) Cannabis and schizophrenia: impact on onset, course, psychopathology and outcomes. Eur Arch Psychiatry Clin Neurosci 252:86–92

14. Hartz SM, Pato CN, Medeiros H et al (2014) Comorbidity of severe psychotic disorders with measures of substance use. JAMA Psychiatry 71:248–254

15. Radhakrishnan R, Wilkinson ST, D’souza DC (2014) Gone to pot—a review of the association between cannabis and psychosis. Front Psychiatry 5:54

16. Falkai P, Rossner MJ, Schulze TG et al (2015) Kraepelin revisited: schizophrenia from degeneration to failed regeneration. Mol Psychiatry 20:671–676

17. Schmitt A, Malchow B, Hasan A et al (2014) The impact of environmental factors in severe psychiatric disorders. Front Neurosci 8:19

18. Bastian H, Glasziou P, Chalmers I (2010) Seventy-five trials and eleven systematic reviews a day: how will we ever keep up? PLoS Med 7:e1000326

19. Smith V, Devane D, Begley CM et al (2011) Methodology in conducting a systematic review of systematic reviews of healthcare interventions. BMC Med Res Methodol 11:15

20. Hoch E, Friemel C, Schneider M (2018) Cannabis: Potenzial und Risiko. In: Hoch E, Friemel C, Schneider M (eds) Eine wissenschaftliche Bestandsaufnahme. Springer, Berlin

21. Äzq (2013) Institut für Medizinisches Wissensmanagement, Ärztliches Zentrum für Qualität in der Medizin. In: “Manual Systematische Literaturrecherche für die Erstellung von Leitlinien”. 1. Auflage 2013. Verfügbar: DCZ: http://www.cochrane.de/de/webliographie-litsuche; AWMF: http://www.awmf.org/leitlinien/awmf-regelwerk/ll-entwicklung.html; ÄZQ: http://www.aezq.de/aezq/publikationen/kooperation

22. Higgins JPT, Green S (2011) Cochrane handbook for systematic reviews of interventions Version 5.1.0. The Cochrane Collaboration, London

23. Hall W, Hoch E, Lorenzetti V (2019) Cannabis use and mental health: risks and benefits. Eur Arch Psychiatry Clin Neurosci 269:1–3

24. Awmf (2012) German Association of the Scientific Medical Societies (AWMF). AWMF-Regelwerk “Leitlinien”. 1. Auflage. In: Standing Guidelines Commission. AWMF guidance manual and rules for guideline development sEEvAahwaola-rh (ed)

25. Ocebm (2011) Levels of evidence working group. In: Oxford Centre for Evidence-Based Medicine O (ed), 2nd edn

26. Moher D, Liberati A, Tetzlaff J et al (2009) Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. BMJ 339:b2535

27. Hemming K, Pinkney T, Futaba K et al (2013) A systematic review of systematic reviews and panoramic meta-analysis: staples versus sutures for surgical procedures. PLoS ONE 8:e75132

28. Sign (2015) Scottisch intercollegiate guidelines network 50 methodology checklist. Edinburgh, UK

29. Burns JK (2012) Cannabis use and duration of untreated psychosis: a systematic review and meta-analysis. Curr Pharm Des 18:5093–5104

30. Koskinen J, Lohonen J, Koponen H et al (2010) Rate of cannabis use disorders in clinical samples of patients with schizophrenia: a meta-analysis. Schizophr Bull 36:1115–1130

31. Kraan T, Velthorst E, Koenders L et al (2016) Cannabis use and transition to psychosis in individuals at ultra-high risk: review and meta-analysis. Psychol Med 46:673–681

32. Large M, Sharma S, Compton MT et al (2011) Cannabis use and earlier onset of psychosis: a systematic meta-analysis. Arch Gen Psychiatry 68:555–561

33. Linscott RJ, Van Os J (2013) An updated and conservative systematic review and meta-analysis of epidemiological evidence on psychotic experiences in children and adults: on the pathway from proneness to persistence to dimensional expression across mental disorders. Psychol Med 43:1133–1149

34. Marconi A, Di Forti M, Lewis CM et al (2016) Meta-analysis of the association between the level of cannabis use and risk of psychosis. Schizophr Bull 42:1262–1269

35. Moore TH, Zammit S, Lingford-Hughes A et al (2007) Cannabis use and risk of psychotic or affective mental health outcomes: a systematic review. Lancet 370:319–328

36. Myles H, Myles N, Large M (2016) Cannabis use in first episode psychosis: meta-analysis of prevalence, and the time course of initiation and continued use. Aust N Z J Psychiatry 50:208–219

37. Myles N, Newall H, Nielssen O et al (2012) The association between cannabis use and earlier age at onset of schizophrenia and other psychoses: meta-analysis of possible confounding factors. Curr Pharm Des 18:5055–5069

38. Potvin S, Sepehry AA, Stip E (2007) Meta-analysis of depressive symptoms in dual-diagnosis schizophrenia. Aust N Z J Psychiatry 41:792–799

39. Potvin S, Sepehry AA, Stip E (2006) A meta-analysis of negative symptoms in dual diagnosis schizophrenia. Psychol Med 36:431–440

40. Sara GE, Large MM, Matheson SL et al (2015) Stimulant use disorders in people with psychosis: a meta-analysis of rate and factors affecting variation. Aust N Z J Psychiatry 49:106–117

41. Semple DM, Mcintosh AM, Lawrie SM (2005) Cannabis as a risk factor for psychosis: systematic review. J Psychopharmacol 19:187–194

42. Szoke A, Galliot AM, Richard JR et al (2014) Association between cannabis use and schizotypal dimensions—a meta-analysis of cross-sectional studies. Psychiatry Res 219:58–66

43. Baldacchino A, Hughes Z, Kehoe M et al (2012) Cannabis psychosis: examining the evidence for a distinctive psychopathology in a systematic and narrative review. Am J Addict 21(Suppl 1):S88–S98

44. Ben Amar M, Potvin S (2007) Cannabis and psychosis: what is the link? J Psychoact Drugs 39:131–142

45. Cookey J, Bernier D, Tibbo PG (2014) White matter changes in early phase schizophrenia and cannabis use: an update and systematic review of diffusion tensor imaging studies. Schizophr Res 156:137–142

46. Ferretjans R, Moreira FA, Teixeira AL et al (2012) The endocannabinoid system and its role in schizophrenia: a systematic review of the literature. Revista brasileira de psiquiatria 34(Suppl 2):S163–S177

47. Geoffroy PA, Etain B, Houenou J (2013) Gene × environment interactions in schizophrenia and bipolar disorder: evidence from neuroimaging. Front Psychiatry 4:136

48. James A, James C, Thwaites T (2013) The brain effects of cannabis in healthy adolescents and in adolescents with schizophrenia: a systematic review. Psychiatry Res 214:181–189

49. Malchow B, Hasan A, Fusar-Poli P et al (2013) Cannabis abuse and brain morphology in schizophrenia: a review of the available evidence. Eur Arch Psychiatry Clin Neurosci 263:3–13

50. Rapp C, Bugra H, Riecher-Rossler A et al (2012) Effects of cannabis use on human brain structure in psychosis: a systematic review combining in vivo structural neuroimaging and post mortem studies. Curr Pharm Des 18:5070–5080

51. Serafini G, Pompili M, Innamorati M et al (2012) Can cannabis increase the suicide risk in psychosis? A critical review. Curr Pharm Des 18:5165–5187

52. Vera U, Annarita T, Rocco P et al (2013) Cannabis and psychosis: a systematic review of genetic studies. Curr Psychiatry Rev 9:302–315

53. Zammit S, Moore TH, Lingford-Hughes A et al (2008) Effects of cannabis use on outcomes of psychotic disorders: systematic review. Br J Psychiatry 193:357–363

54. Gage SH, Jones HJ, Burgess S et al (2017) Assessing causality in associations between cannabis use and schizophrenia risk: a two-sample Mendelian randomization study. Psychol Med 47:971–980

55. Buchanan RW, Kreyenbuhl J, Kelly DL et al (2010) The 2009 schizophrenia PORT psychopharmacological treatment recommendations and summary statements. Schizophr Bull 36:71–93

56. DGPPN (2019) S3-Leitlinie Schizophrenie 2019. Available online: https://www.awmf.org/leitlinien/detail/ll/038-009.html

57. Galletly C, Castle D, Dark F et al (2016) Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for the management of schizophrenia and related disorders. Aust N Z J Psychiatry 50:410–472

58. Hasan A, Falkai P, Wobrock T et al (2015) World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for biological treatment of schizophrenia. Part 3: update 2015 management of special circumstances: depression, suicidality, substance use disorders and pregnancy and lactation. World J Biol Psychiatry 16:142–170

59. Colizzi M, Murray R (2018) Cannabis and psychosis: what do we know and what should we do? Br J Psychiatry 212:195–196

60. Ruther T, Bobes J, De Hert M et al (2014) EPA guidance on tobacco dependence and strategies for smoking cessation in people with mental illness. Eur Psychiatry 29:65–82

61. Nielsen SM, Toftdahl NG, Nordentoft M et al (2017) Association between alcohol, cannabis, and other illicit substance abuse and risk of developing schizophrenia: a nationwide population based register study. Psychol Med 47:1668–1677

62. Hjorthoj C, Albert N, Nordentoft M (2018) Association of substance use disorders with conversion from schizotypal disorder to schizophrenia. JAMA Psychiatry 75:733–739