Prediction From
of Adult-Onset
Childhood
Elaine
Walker,
Home
Ph.D.,
and
In a preliminary study of developmental precursors of schizophrenia, home movies of adult-onset schizophrenic patients and their healthy siblings filmed during their childhood were viewed by judges who were blind to the psychiatric outcome of the subjects. The films began with the infancy of all subjects and extended through at least the first S years of their lives. Although none of the subjects had any psychiatric disorder in childhood, the preschizophrenic children were reliably identified by the viewers. This represents the fi rst demonstration that preschizophrenic subjects can be distinguished from sibling control subjects within the first 8 years of life by observing their behavior. (AmJ Psychiatry 1990; 147:1052-1056)
S
chizophrenia has generally been conceptualized as an adult-onset disorder, because the modal age at clinical onset is 20-25 years (1 ). However, there is reason to believe that the neuropathology underlying schizophrenia may be present early in life, perhaps at birth (2-5). The results of twin and adoption studies, as well as recent genetic linkage studies, indicate that heredity plays a role in schizophrenia (1). Obviously, in cases where genetic factors are operative, constitutional vulnerability would be congenital. Further support for congenital vulnerability comes from findings that a subgroup of schizophrenic patients manifested brain abnormalities on CT and magnetic resonance imaging scans that suggested long-standing structural impairment (4). However, despite the widespread assumption that at least some schizophrenic disorders involve a neuropathology that is present at birth, we have little knowledge of the developmental course that precedes the clinical onset of the disorder. Lewis (6) has pointed out that “the enormous efforts that have been made in defining a phenotype in cross-section have not yet been matched by proper consideration of longitudinal features.” To date, information on the developmental precur-
Receivedjuly 28, 1989; revision received Nov. 14, 1989; accepted Jan. 25, 1990. From the Department of Psychology, Emory University. Address reprint requests to Dr. Walker, Department of Psychology, Emory University, Atlanta, GA 30322. Copyright © 1990 American Psychiatric Association.
1052
Movies
Richard
Schizophrenia of the Patients J. Lewine,
Ph.D.
sons of adult-onset schizophrenia has come from three sources : retrospective reports, follow-back studies, and prospective research on high-risk subjects. Investigations based on retrospective parental reports have yielded inconsistent results; for example, some suggest that there is a higher incidence of peminatal and early infancy complications among preschizophrenic mdividuals, and others do not (7, 8). The potential unreliability of retrospective data provided the impetus for follow-back studies of school records (grades, test scores, and teachers’ anecdotal comments about the child’s behavior). With the use of this latter method, the earliest point at which preschizophnenic subjects were distinguishable from control subjects on the basis of classroom behavior was early adolescence; the preschizophrenic subjects showed greater behavioral problems (9). Significant deficits in test scores have been found in schizophrenic patients as early as the firstgrade (10). Prospective studies of the developmental precursors of schizophrenia in high-risk subjects have focused on the biological offspring of schizophrenic parents (1 1). The subjects of most of these studies have not passed through the major risk period for schizophrenia, so the outcomes are not yet known. However, offspring of schizophrenic parents have been shown to manifest deficits in motor, cognitive, and interpersonal functioning when compared to children of normal parents (11). The question of whether these deficits are uniquely related to schizophrenic disorders in adulthood remains unanswered (12). The fact that we know so little about the developmental precursors of schizophrenia has been a major obstacle in our efforts to generate etiological models of the disorder. Specifically, the following critical questions must be addressed. 1) Are individuals who develop schizophrenia in adulthood distinguishable from control subjects in childhood? 2) What is the earliest point in the life course that signs of vulnerability are apparent? 3) What is the nature of the manifestations of vulnerability? The present investigation represents a first step in our attempt to address these questions through the application of an “archival-observational” approach that uses home movies of patients when they were children as the primary database on development. The use of home movies provides a unique opportunity for di-
Am
J
Psychiatry
1 47:8,
August
1990
ELAINE
rectly examining the childhood behavior of individuals whose adult psychiatric outcome is known. Moreover, healthy siblings serve as an ideal comparison group because they are featured in the same films within the same behavioral contexts. In future research we will use systematic observational procedures to obtain data on the socioemotional and neuromotor development of the subjects. The central goal in this preliminary study was to determine whether viewers who were blind to the adult psychiatric outcome of the subjects would be able to distinguish the preschizophnenic children from their healthy siblings. Specifically, we sought to determine whether the preschizophrenic children could be reliably identified before they were 8 years of age. We expected the findings from this preliminany study to shed light on the feasibility of this new method for exploring developmental precursors. Further, before subjecting the films to analysis with micnolevel coding schemes, it was important for us to know whether the viewers would be capable of detecting the target children without the benefit of specific criteria.
METHOD Although the patients and their siblings are the focus of this research program, the individuals viewing the films were the actual subjects of the present study. The viewers were graduate students in psychology (N 13) and experienced clinicians (N6). The experienced clinicians were four doctoral-level psychologists, one psychiatrist, and one master’s-level psychiatric nurse. With the exception of one psychologist who is now primarily involved in developmental research, all of the experienced viewers were actively engaged in work with psychiatric patients at the time of the study (one with adults only and the others with both children and adults). The subjects featured in the films are five schizophrenic patients (four male and one female) and their healthy siblings who are past the age of 25 years and have no history of psychiatric disorder. Subjects were selected from a larger sample of 15 patients on the basis of criteria that we shall describe. Informed consent was obtained from the participants after the procedures and goals of the study had been fully explained. In every case, the patient was the only one in his or her nuclear family who had a psychiatric disorder. The patients were diagnosed as schizophrenic in late adolescence or early adulthood and have been under continuous medical care since the onset of their illness (current mean±SD age of the patients=29±S.2 years). None of the patients was referred for on received treatment for psychiatric problems before the age of 17, non did any of them have physical illnesses on handicaps that would set them apart from their siblings. All of the patients currently meet the DSM-III-R criteria for schizophrenia. Diagnostic information was gathered
Am
J
Psychiatry
147:8,
August
1990
WALKER
AND
RICHARD
J.
LEWINE
through a structured clinical interview, the Schedule for Affective Disorders and Schizophrenia (SADS) (13), with the subject and medical history information provided by the parents. The diagnostic interviewer was a doctoral-level psychologist (E.W.) trained in the administration of the SADS. Three of the five patients were also independently given diagnoses by another interviewer using the SADS, and there was 100% consensus. All available 8- and 16-mm home movies of the patients and their siblings were submitted for study. These were transcribed to videotape, and the tapes were edited to eliminate footage that did not feature one on more of the children in the sibship. The ages of the children in the films were determined on the basis of information provided by the parents as well as the film content. Chronologically ordered segments were prepared for viewing. Because the children enter the films in order of birth, some of the initial segments did not include all of the children in a sibship. However, all segments included all children born before the date on which the segment ended. Also, because the siblings enter the films in order of birth and are subsequently featured simultaneously in the films, it was not possible to make the length of time they were featured or the age span covered the same for all children within a sibship. However, for all subjects, the films included footage taken during the first 17 months of life and extended to at least the fifth year. The viewers were blind to the identity and psychiatnic status of the subjects in the films. They were informed that they would be viewing videotape segments of sibships in which only one child developed schizophrenia later in life. To avoid biasing the viewers by directing their attention to particular characteristics of the subjects, we provided no criteria for judging the children. The viewers were instructed to use their own criteria in judging the eventual psychiatric status of the children and to note on their response forms the factons that influenced their judgments. In this way we could determine which features of the children were most salient to the individual viewers in making their judgments. We provided the viewers with standard forms on which to record their responses and instructed them to remain silent while viewing the videotapes and refrain from sharing their responses with others. The viewers were informed of the ages of the children featured in each of the chronologically ordered segments. After each segment was shown, they were asked to respond yes or no (forced choice) to the question “Is this the pneschizophrenic child?” They were to choose one and only one child from the sibship. Once they recorded their judgments, the viewers were not permitted to change them; however, they were free to judge the children differently after viewing subsequent segments. In cases where the initial film segment included only a subset of the siblings, viewers were not required to choose one of them. In addition to the forced-choice response, the viewers were asked to in-
1053
PREDICTION
OF
SCHIZOPHRENIA
FROM
MOVIES
dicate their confidence in their judgment of each child on a 4-point scale: 0=no confidence, 1=somewhat confident, 2 =confident, 3 very confident. We used a forced-choice procedure so that the mesultant data would be suitable for probability analyses. Further, with this procedure individual differences among viewers in decision or response thresholds (i.e., threshold for affirmative responses) do not influence outcomes. A pilot study was conducted with films of one male patient and his siblings to determine the suitability of the rating procedures. A group of seven graduate students in psychology viewed 10 film segments (5-10 minutes each) of the sibship, which was composed of five children (four male and one female); the patient was the second born. He had shown an onset of symptoms at 22 years of age, at which time he first received treatment. The total duration of the videotape was 60 minutes, and it began with the birth of the first child and extended to the fifth birthday of the last-born child. We subjected the final judgments of the viewers (i.e., those made after viewing all segments of the film) to the binomial test, using the tables listing the critical values for binomial judgments, with varying probabilities of events, in the textbook by Runyon and Haber (14). In their final judgments, five of the seven viewers correctly identified the preschizophrenic child, although there was no relation between confidence matings and accuracy. The probability (p) value associated with five of seven correct, when P0.20 and Q0.80, is
of Adult-Onset
Childhood
Elaine
Walker,
Home
Ph.D.,
and
In a preliminary study of developmental precursors of schizophrenia, home movies of adult-onset schizophrenic patients and their healthy siblings filmed during their childhood were viewed by judges who were blind to the psychiatric outcome of the subjects. The films began with the infancy of all subjects and extended through at least the first S years of their lives. Although none of the subjects had any psychiatric disorder in childhood, the preschizophrenic children were reliably identified by the viewers. This represents the fi rst demonstration that preschizophrenic subjects can be distinguished from sibling control subjects within the first 8 years of life by observing their behavior. (AmJ Psychiatry 1990; 147:1052-1056)
S
chizophrenia has generally been conceptualized as an adult-onset disorder, because the modal age at clinical onset is 20-25 years (1 ). However, there is reason to believe that the neuropathology underlying schizophrenia may be present early in life, perhaps at birth (2-5). The results of twin and adoption studies, as well as recent genetic linkage studies, indicate that heredity plays a role in schizophrenia (1). Obviously, in cases where genetic factors are operative, constitutional vulnerability would be congenital. Further support for congenital vulnerability comes from findings that a subgroup of schizophrenic patients manifested brain abnormalities on CT and magnetic resonance imaging scans that suggested long-standing structural impairment (4). However, despite the widespread assumption that at least some schizophrenic disorders involve a neuropathology that is present at birth, we have little knowledge of the developmental course that precedes the clinical onset of the disorder. Lewis (6) has pointed out that “the enormous efforts that have been made in defining a phenotype in cross-section have not yet been matched by proper consideration of longitudinal features.” To date, information on the developmental precur-
Receivedjuly 28, 1989; revision received Nov. 14, 1989; accepted Jan. 25, 1990. From the Department of Psychology, Emory University. Address reprint requests to Dr. Walker, Department of Psychology, Emory University, Atlanta, GA 30322. Copyright © 1990 American Psychiatric Association.
1052
Movies
Richard
Schizophrenia of the Patients J. Lewine,
Ph.D.
sons of adult-onset schizophrenia has come from three sources : retrospective reports, follow-back studies, and prospective research on high-risk subjects. Investigations based on retrospective parental reports have yielded inconsistent results; for example, some suggest that there is a higher incidence of peminatal and early infancy complications among preschizophrenic mdividuals, and others do not (7, 8). The potential unreliability of retrospective data provided the impetus for follow-back studies of school records (grades, test scores, and teachers’ anecdotal comments about the child’s behavior). With the use of this latter method, the earliest point at which preschizophnenic subjects were distinguishable from control subjects on the basis of classroom behavior was early adolescence; the preschizophrenic subjects showed greater behavioral problems (9). Significant deficits in test scores have been found in schizophrenic patients as early as the firstgrade (10). Prospective studies of the developmental precursors of schizophrenia in high-risk subjects have focused on the biological offspring of schizophrenic parents (1 1). The subjects of most of these studies have not passed through the major risk period for schizophrenia, so the outcomes are not yet known. However, offspring of schizophrenic parents have been shown to manifest deficits in motor, cognitive, and interpersonal functioning when compared to children of normal parents (11). The question of whether these deficits are uniquely related to schizophrenic disorders in adulthood remains unanswered (12). The fact that we know so little about the developmental precursors of schizophrenia has been a major obstacle in our efforts to generate etiological models of the disorder. Specifically, the following critical questions must be addressed. 1) Are individuals who develop schizophrenia in adulthood distinguishable from control subjects in childhood? 2) What is the earliest point in the life course that signs of vulnerability are apparent? 3) What is the nature of the manifestations of vulnerability? The present investigation represents a first step in our attempt to address these questions through the application of an “archival-observational” approach that uses home movies of patients when they were children as the primary database on development. The use of home movies provides a unique opportunity for di-
Am
J
Psychiatry
1 47:8,
August
1990
ELAINE
rectly examining the childhood behavior of individuals whose adult psychiatric outcome is known. Moreover, healthy siblings serve as an ideal comparison group because they are featured in the same films within the same behavioral contexts. In future research we will use systematic observational procedures to obtain data on the socioemotional and neuromotor development of the subjects. The central goal in this preliminary study was to determine whether viewers who were blind to the adult psychiatric outcome of the subjects would be able to distinguish the preschizophnenic children from their healthy siblings. Specifically, we sought to determine whether the preschizophrenic children could be reliably identified before they were 8 years of age. We expected the findings from this preliminany study to shed light on the feasibility of this new method for exploring developmental precursors. Further, before subjecting the films to analysis with micnolevel coding schemes, it was important for us to know whether the viewers would be capable of detecting the target children without the benefit of specific criteria.
METHOD Although the patients and their siblings are the focus of this research program, the individuals viewing the films were the actual subjects of the present study. The viewers were graduate students in psychology (N 13) and experienced clinicians (N6). The experienced clinicians were four doctoral-level psychologists, one psychiatrist, and one master’s-level psychiatric nurse. With the exception of one psychologist who is now primarily involved in developmental research, all of the experienced viewers were actively engaged in work with psychiatric patients at the time of the study (one with adults only and the others with both children and adults). The subjects featured in the films are five schizophrenic patients (four male and one female) and their healthy siblings who are past the age of 25 years and have no history of psychiatric disorder. Subjects were selected from a larger sample of 15 patients on the basis of criteria that we shall describe. Informed consent was obtained from the participants after the procedures and goals of the study had been fully explained. In every case, the patient was the only one in his or her nuclear family who had a psychiatric disorder. The patients were diagnosed as schizophrenic in late adolescence or early adulthood and have been under continuous medical care since the onset of their illness (current mean±SD age of the patients=29±S.2 years). None of the patients was referred for on received treatment for psychiatric problems before the age of 17, non did any of them have physical illnesses on handicaps that would set them apart from their siblings. All of the patients currently meet the DSM-III-R criteria for schizophrenia. Diagnostic information was gathered
Am
J
Psychiatry
147:8,
August
1990
WALKER
AND
RICHARD
J.
LEWINE
through a structured clinical interview, the Schedule for Affective Disorders and Schizophrenia (SADS) (13), with the subject and medical history information provided by the parents. The diagnostic interviewer was a doctoral-level psychologist (E.W.) trained in the administration of the SADS. Three of the five patients were also independently given diagnoses by another interviewer using the SADS, and there was 100% consensus. All available 8- and 16-mm home movies of the patients and their siblings were submitted for study. These were transcribed to videotape, and the tapes were edited to eliminate footage that did not feature one on more of the children in the sibship. The ages of the children in the films were determined on the basis of information provided by the parents as well as the film content. Chronologically ordered segments were prepared for viewing. Because the children enter the films in order of birth, some of the initial segments did not include all of the children in a sibship. However, all segments included all children born before the date on which the segment ended. Also, because the siblings enter the films in order of birth and are subsequently featured simultaneously in the films, it was not possible to make the length of time they were featured or the age span covered the same for all children within a sibship. However, for all subjects, the films included footage taken during the first 17 months of life and extended to at least the fifth year. The viewers were blind to the identity and psychiatnic status of the subjects in the films. They were informed that they would be viewing videotape segments of sibships in which only one child developed schizophrenia later in life. To avoid biasing the viewers by directing their attention to particular characteristics of the subjects, we provided no criteria for judging the children. The viewers were instructed to use their own criteria in judging the eventual psychiatric status of the children and to note on their response forms the factons that influenced their judgments. In this way we could determine which features of the children were most salient to the individual viewers in making their judgments. We provided the viewers with standard forms on which to record their responses and instructed them to remain silent while viewing the videotapes and refrain from sharing their responses with others. The viewers were informed of the ages of the children featured in each of the chronologically ordered segments. After each segment was shown, they were asked to respond yes or no (forced choice) to the question “Is this the pneschizophrenic child?” They were to choose one and only one child from the sibship. Once they recorded their judgments, the viewers were not permitted to change them; however, they were free to judge the children differently after viewing subsequent segments. In cases where the initial film segment included only a subset of the siblings, viewers were not required to choose one of them. In addition to the forced-choice response, the viewers were asked to in-
1053
PREDICTION
OF
SCHIZOPHRENIA
FROM
MOVIES
dicate their confidence in their judgment of each child on a 4-point scale: 0=no confidence, 1=somewhat confident, 2 =confident, 3 very confident. We used a forced-choice procedure so that the mesultant data would be suitable for probability analyses. Further, with this procedure individual differences among viewers in decision or response thresholds (i.e., threshold for affirmative responses) do not influence outcomes. A pilot study was conducted with films of one male patient and his siblings to determine the suitability of the rating procedures. A group of seven graduate students in psychology viewed 10 film segments (5-10 minutes each) of the sibship, which was composed of five children (four male and one female); the patient was the second born. He had shown an onset of symptoms at 22 years of age, at which time he first received treatment. The total duration of the videotape was 60 minutes, and it began with the birth of the first child and extended to the fifth birthday of the last-born child. We subjected the final judgments of the viewers (i.e., those made after viewing all segments of the film) to the binomial test, using the tables listing the critical values for binomial judgments, with varying probabilities of events, in the textbook by Runyon and Haber (14). In their final judgments, five of the seven viewers correctly identified the preschizophrenic child, although there was no relation between confidence matings and accuracy. The probability (p) value associated with five of seven correct, when P0.20 and Q0.80, is
