title: Maternal age and trajectories of cannabis use.
abstract: BACKGROUND
  Becoming a mother is a developmental transition that has been linked to desistance from substance use. However, timing of motherhood may be a key determinant of cannabis use in women, based on preliminary evidence from teenage mothers. The goal of this study was to identify trajectories of maternal cannabis use, and to determine if maternal age was associated with different trajectories of use.
  
  
  METHODS
  This prospective study examined 456 pregnant women recruited at a prenatal clinic, ranging in age from 13 to 42 years. The women were interviewed about their cannabis use 1 year prior to pregnancy and during each trimester of pregnancy, and at 6, 10, 14, and 16 years post-partum.
  
  
  RESULTS
  A growth mixture model of cannabis use reported at each time point clearly delineated four groups: non/unlikely to use, decreasing likelihood of use, late desistance, and increasing likelihood/chronic use (Lo-Mendell-Rubin adjusted LRT test statistic=35.7, p<.001). The youngest mothers were least likely to be in the "non/unlikely to use" group. Younger maternal age also differentiated between late desistance and increasing likelihood/chronic use, versus decreasing likelihood of use post-partum.
  
  
  CONCLUSIONS
  This is the first study to demonstrate that younger mothers are more likely to use cannabis across 17 years, including later desistance post-partum and increasing/chronic use. Other substance use and chronic depressive symptoms were also associated with more frequent use. These findings have implications for both prevention and treatment of cannabis use in mothers.
authors.affiliation: Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA. Electronic address: degennan@pitt.edu.
authors.forename: Natacha M
authors.initials: NM
authors.lastname: De Genna
authors.affiliation: Departments of Psychiatry and Epidemiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA. Electronic address: mdc1@pitt.edu.
authors.forename: Marie D
authors.initials: MD
authors.lastname: Cornelius
authors.affiliation: Western Psychiatric Institute and Clinic (WPIC), University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA. Electronic address: lidush@pitt.edu.
authors.forename: Lidush
authors.initials: L
authors.lastname: Goldschmidt
authors.affiliation: Departments of Psychiatry, Epidemiology, Pediatrics, and Occupational Therapy, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA. Electronic address: nday@pitt.edu.
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Day
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D003863:Depression / Q000150:complications / Q000453:epidemiology; D005260:Female; D006791:Hostility; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology* / Q000523:psychology*; D008423:Maternal Age; D009035:Mothers; D011247:Pregnancy; D011446:Prospective Studies; D012959:Socioeconomic Factors; D019966:Substance-Related Disorders / Q000150:complications / Q000453:epidemiology; D055815:Young Adult
keywords: Cannabis; Desistance; Marijuana; Maternal; Mother; Women