This article combines a review and meta-analysis of research on IQ in schizophrenia, with emphasis on areas of convergence in the findings, as well as questions that remain to be answered. Taken together, the findings suggest that early-onset and adult-onset schizophrenia are associated with intellectual deficits across the lifespan. Preschizophrenic children, adolescents, and young adults perform below matched controls on a variety of standardized measures of intelligence. Significant IQ deficits are also apparent after the onset of the disorder. Moreover, IQ is positively related to several indices of prognosis, and, among hospitalized patients, there is negative within-subject covariance between intellectual performance and symptom severity. Although there is fairly consistent evidence that Verbal IQ is higher than Performance IQ among schizophrenic patients, a more specific pattern of subtest performance is not apparent. A central question raised by the results is whether IQ is an independently determined factor that can serve to mitigate the vulnerability of individuals who are constitutionally predisposed to schizophrenia, or whether intellectual deficit is one manifestation of the constitutional predisposition to the disorder. The findings also raise the question of possible sex differences in the developmental determinants of schizophrenia: Meta-analyses revealed that premorbid IQ deficits are more prevalent among males than females.

Children of depressed parents are at increased risk for depression and other developmental problems. Recent research indicates that disturbances exist in face-to-face interactions between depressed mothers and their infants. In the present study, the effects of maternal depression on motherese, an interactive behavior that plays a significant role in affective, cognitive, and social development, were examined. 2 paralinguistic features of motherese were examined: temporal parameters of utterances and pauses and the frequency of use of 5 types of intonation contours typically found in motherese utterances. Face-to-face interactions between 36 mothers and their 3-4-month-old infants were audio-recorded, and hard copy records of pitch contours and relative intensity were produced for 2-min interaction sequences. Results indicated that depressed mothers failed to modify their behavior according to the behavior of the infant. They were significantly slower to respond to an infant vocalization, had more variable utterances and pauses, and were less likely to utilize the exaggerated intonation contours that are characteristic of motherese. The results provide evidence for a mechanism through which maternal depression increases the infant's risk for psychopathology.

Schizophrenics have been shown to manifest a significant deficit in identifying facial expressions of emotion. The present study sought to determine whether this deficit lay at the level of decoding facial cues of emotion, or whether it is specific to the process of labelling emotional faces. The latter specific deficit would be consistent with the hypothesis of left-hemisphere dysfunction in schizophrenia. Samples of schizophrenics, patients with affective disorders and normal controls were tested on a battery of facial tasks that had previously been shown to be capable of distinguishing between patients with left- and right-hemisphere lesions. The battery was comprised of four tests: facial discrimination, emotion discrimination, emotion labelling, and a multiple choice emotion task. The performance of affective patients fell midway between that of schizophrenics and normals on all the tasks. Schizophrenics performed significantly below normals on all but the facial discrimination task, and below affective patients on the emotion labelling task. There were no other significant group differences in performance. The performance pattern manifested by schizophrenics across the four tasks is not comparable to that shown by patients with unilateral brain damage. These results indicate that previously reported emotion identification deficits in schizophrenia were not solely a function of the labelling requirements of the tasks. Instead it appears that schizophrenics, although capable of deciphering facial cues of identity, are impaired in the ability to extract salient emotional cues from faces.

Children of depressed parents are at increased risk for depression and other developmental problems. Recent research indicates that disturbances exist in face-to-face interactions between depressed mothers and their infants. In the present study, the effects of maternal depression on motherese, an interactive behavior that plays a significant role in affective, cognitive, and social development, were examined. 2 paralinguistic features of motherese were examined: temporal parameters of utterances and pauses and the frequency of use of 5 types of intonation contours typically found in motherese utterances. Face-to-face interactions between 36 mothers and their 3-4-month-old infants were audio-recorded, and hard copy records of pitch contours and relative intensity were produced for 2-min interaction sequences. Results indicated that depressed mothers failed to modify their behavior according to the behavior of the infant. They were significantly slower to respond to an infant vocalization, had more variable utterances and pauses, and were less likely to utilize the exaggerated intonation contours that are characteristic of motherese. The results provide evidence for a mechanism through which maternal depression increases the infant's risk for psychopathology.

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