Psychological Medicine

Original Articles

Developmental trajectories of psychotic-like experiences across adolescence: impact of victimization and substance use

C. J. Mackiea1 c1, N. Castellanos-Ryana1 and P. J. Conroda1

a1 Addictions Department, Division of Psychological Medicine and Psychiatry, Institute of Psychiatry, King's College London, UK


Background Research suggests that psychotic-like experiences (PLEs) in the general population are common, but can reflect either transitory or persistent developmental phenomena. Using a general adolescent population it was examined whether different developmental subtypes of PLEs exist and whether different trajectories of PLEs are associated with certain environmental risk factors, such as victimization and substance use.

Method Self-reported PLEs were collected from 409 adolescents (mean age 14 years 7 months) at four time points, each 6 months apart. General growth mixture modelling was utilized to identify classes of adolescents who followed distinct trajectories of PLEs across this period. Predictors of class membership included demographics, personality, victimization, depression, anxiety and substance use.

Results We identified the following three developmental subgroups of PLEs: (1) persistent; (2) increasing; (3) low. Adolescents on the persistent trajectory reported frequent victimization and consistent elevated scores in depression and anxiety. Adolescents on the increasing trajectory were engaging in cigarette use prior to any increases in PLEs and were engaging in cocaine, cannabis and other drug use as PLEs increased at later time points.

Conclusions The findings suggest that different developmental subgroups of PLEs exist in adolescence and are differentially related to victimization and substance use.

(Received September 04 2009)

(Revised February 10 2010)

(Accepted February 20 2010)

(Online publication March 29 2010)


c1 Address for correspondence: Dr C. J. Mackie, Institute of Psychiatry, KCL, 4 Windsor Walk, London SE5 8AF, UK. (Email: