Table 4.
Birth Cohort Studies of Speech and Language Functioning as Antecedents of Schizophrenia?
| Birth Cohorts | Specific Methods |
|||
| Studies | Ages (y) | Components | Instruments/Analyses | Results |
| NSHD UK1946 | ||||
| Jones et al15 | 2, 6, 7, 11, 15 | Speech acquisition and quality | Health visitor/physician records | Speech delay at 2 y; up to age 15, cases had more speech problems than controls (OR 2.8 (0·9–7·8), P = .04) |
| NCDS UK1958 | ||||
| Crow et al42 | 7 | Speech acquisition and quality; oral or reading | Parental and teacher assessment | Parents rated pre-sz speech acquisition and quality as normal. Teachers rated pre-sz speech and reading as poor. |
| 11 | Speech, English | Teacher assessment | Teachers rated pre-sz speech as poor. | |
| NCPP Philadelphia | ||||
| Bearden et al35 | 7 | Receptive and expressive language; speech intelligibility; language ability | Speech pathologist assessment; Auditory-Vocal Association Test | Abnormal speech predicted adult sz (OR = 12.70 95%CI = 2.46–65.66); language performance was negatively associated with sz (OR = 0.71, 95% CI = 0.57–0.89). |
| MHDS, Dunedin, New Zealand | ||||
| Cannon et al38 | 3 and 5 | (All ages) Receptive and expressive language | Reynell Developmental Language Scales | All ages: schizophreniform group receptive (but not expressive) language was significantly poorer than controls (between 0.2 and 0.6 SDs). |
| 7 and 9 | Illinois Test of Psycholinguistic Abilities | Various adjustment including OCs had little effect. | ||
Note: NSHD, National Survey of Health and Development; OR, odds ratio; NCDS, National Child Development Survey; CI, confidence interval; DMHDS, Dunedin Multidisciplinary Health and Development Study; OCs, obstetric complications.