https://doi.org/10.1177/0269881117711920 Journal of Psychopharmacology 1–11 © The Author(s) 2017 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0269881117711920 journals.sagepub.com/home/jop Introduction Cannabis-induced psychosis (CIPD) is one clinical entity asso- ciated with cannabis consumption (Mathias et al., 2008). The prevalence and aetiology of this disorder is still unknown and scarce research has been carried out, mainly due to the evanes- cence characteristics of their symptoms (American Psychiatric Association, 1994). The association of this disorder with schiz- ophrenia has not yet been clarified. CIPD, frequently found in relatives of patients with schizophrenia and the potential risk for developing schizophrenia in some patients with CIPD, has led some authors to consider CIPD as an early sign of schizo- phrenia (Arendt et al., 2008). More specifically, previous stud- ies found that almost half of the patients diagnosed with CIPD later developed a schizophrenia spectrum disorder (Arendt et al., 2005). However, more recent results indicated that there is still scarce evidence supporting the fact that patients with CIPD will present a greater risk of transition from brief psy- chotic episodes to schizophrenia compared with those who do not use cannabis (Manrique-Garcia et al., 2012). One reason that could explain these contradictory results might be the Psychological symptomatology and impaired prepulse inhibition of the startle reflex are associated with cannabis-induced psychosis Isabel Morales-Muñoz 1,2 , Isabel Martínez-Gras 2,3,4,5 , Guillermo Ponce 2,3,4,5 , Javier de la Cruz 2,3 , David Lora 6,7 , Roberto Rodríguez-Jiménez 2,3,4,8 , Rosa Jurado-Barba 2,3,8 , Francisco Navarrete 5,9 , María Salud García-Gutiérrez 5,9 , Jorge Manzanares 5,9 and Gabriel Rubio 2,3,4,5 Abstract Background: Cannabis-induced psychotic disorder (CIPD) is a psychiatric disorder induced by cannabis consumption. The psychological and psychophysiological features of this disorder are still unknown. We aimed to examine the psychological, personality and psychophysiological features of patients with CIPD. This study is an analytical extension of our previously published data, which previously found prepulse inhibition (PPI) deficits in the CIPD group used in this current paper. Methods: We used a sample of 45 patients with CIPD. After 9 months of follow up, these patients were assessed with a Symptom Checklist-90-R (SCL-90-R) questionnaire of psychopathology, with the Eysenck Personality Questionnaire, and with a psychophysiological paradigm of inhibition of the startle reflex (PPI). These results were compared with a group of patients with schizophrenia and cannabis abuse (SCHZ) (n = 54); patients with cannabis dependence (CD) (n = 21); and healthy controls (n = 50). Results: CIPD patients obtained significant higher scores in the SCL-90-R subscale of neuroticism. These patients showed PPI percentages similar to SCHZ patients within early attentional levels (30 ms). The variables with greater correlation, and that appeared in the CIPD group were interpersonal sensitivity, depression and phobia. Conclusions: Neurotic symptomatology and difficulties in inhibition of the startle reflex might be risk factors for developing CIPD. Keywords Cannabis-induced psychotic disorder, psychology, prepulse inhibition, sensory gating 1 Department of Health, National Institute for Health and Welfare (THL), Helsinki, Finland 2 Research Institute 12-i, Madrid, Spain 3 Hospital Universitario 12 de Octubre, Madrid, Spain 4 Department of Psychiatry, Complutense University of Madrid, Madrid, Spain 5 Red temática de Investigación cooperativa en salud (RETIS-Trastornos adictivos), Instituto Carlos III, MICINN and FEDER, Madrid, Spain 6 Clinical Research Unit (i+12), Hospital Universitario 12 de Octubre, Madrid, Spain 7 CIBER de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain 8 Biomedical Research Center Network for Mental Health (CIBERSAM), Madrid, Spain 9 Institute for Neurosciences, Miguel Hernández University-CSIC, Alicante, Spain Corresponding author: Isabel Morales-Muñoz, Department of Health. National Institute for Health and Welfare (THL), Mannerheimintie 168b, FI-00300, Helsinki, Finland. Email: isabel.morales@thl.fi 711920JOP 0 0 10.1177/0269881117711920Journal of PsychopharmacologyMorales-Muñoz et al. research-article 2017 Original Paper