Table 1.
Descriptive Information for All Covariates Included in the Models
| Measure | Age(s) Assessed | Informant | Description | Prevalence n (%) or M (SD) | |
|---|---|---|---|---|---|
| Childhood Psychotic Symptoms Present | Childhood Psychotic Symptoms Absent | ||||
| Childhood IQ | 5 | Participant | Vocabulary and Block design subtests on a short form of the Wechsler Preschool and Primary Scale of Intelligence-Revised. Children’s IQs were prorated following procedures described by Sattler43 | 89.1 (14.1) | 96.3 (14.4) |
| Low family socioeconomic status | 5 | Parents | Participants’ family socioeconomic status was defined using a standardized composite of parents’ income, education, and social class ascertained at childhood phases of the study, which loaded significantly onto one latent factor.44 The latent factor was divided in tertiles | 53 (42.4) | 658 (32.9) |
| Family history of psychiatric disorder | 12 | Mother | The Family History Screen was used to assess treatment or hospitalization for a DSM psychiatric disorder or substance-use problem or attempted or completed suicide for any of the child’s biological mother, father, grandparents, or aunts and uncles, which was converted to a proportion (0–1.0) of family members with a history of psychiatric disorder45 | 0.5 (0.3) | 0.4 (0.3) |
| Maternal psychosis | 12 | Mother | Maternal history of psychosis was assessed using the Diagnostic Interview Schedule for DSM-IV,30 which provides a symptom count for characteristic symptoms of schizophrenia (eg, hallucinations, delusions, anhedonia). This was dichotomized to 0 vs 1 or more | 33 (26.6) | 317 (15.9) |
| Depression | 12 | Participant | Depressive symptoms were assessed using the Children’s Depression Inventory (CDI).46 Children who scored 20 or more were deemed to have clinically significant depressive symptoms | 12 (9.6) | 105 (5.2) |
| Anxiety | 12 | Participant | Anxiety symptoms were assessed via private interviews using the 10-item version of the Multidimensional Anxiety Scale for Children (MASC).47 An extreme anxiety group was formed with children who scored at or above the 95th percentile | 20 (16.0) | 107 (5.3) |
| Attention-deficit hyperactivity disorder (ADHD) | 5, 7, 10, 12 | Mother Teacher |
ADHD was assessed using the DSM-IV28 and the requirement of symptom onset prior to age 12 was met if parents or teachers reported more than 2 ADHD symptoms at ages 5, 7, 10, or 12 years | 5 (4.6) | 60 (3.2) |
| Conduct disorder | 12 | Mother Teacher |
Diagnoses of conduct disorder were based on mothers’ and teachers’ reports of children’s behavior problems using the Achenbach family of instruments and additional DSM-IV28 items which have previously been described.48 Conduct disorder was assumed present if it was diagnosed at ages 5, 7, 10, or 12 years | 18 (14.4) | 55 (2.7) |
| Childhood suicidal or self-harm behavior | 10, 12 | Mother | Report of self-harm or suicide attempt made in past 6 months, at either assessment | 11 (8.8) | 51 (2.5) |
Note: DSM, Diagnostic and Statistical Manual of Mental Disorders.