Schizophrenia involves profound social and occupational deficits that substantially limit prognosis and long-term recovery. Social and occupational functional disabilities are widely reported to be rooted in early development, to be associated with neurocognitive deficits and negative symptoms, and to appear to be largely independent of positive (ie, psychotic) symptoms. Prospective high risk, birth cohort, and first-episode studies of schizophrenia1–6
have consistently reported preillness social and academic difficulties. For example, findings from the British birth cohort studies indicate a range of early social difficulties (eg, preference for solitary play, social anxiety, and lack of confidence) as well as low educational test scores in preschizophrenic individuals as young as 7 and 11 years of age.1,2
Prospective genetic high-risk projects have also consistently reported similar social and academic deficits in the adolescent offspring of parents with schizophrenia.3,4
More recently, a study of recent-onset schizophrenia patients reported that difficulties in maintaining social networks predated first hospitalization,6
further supporting functional deficits as long-standing traits.
In addition, findings from studies of adult schizophrenia patients indicate that functional outcome is more directly related to neurocognitive deficits and negative symptoms than to positive symptoms.7–11
In support of this view, a number of recent clinical trials have indicated that even with a major decrease in positive symptoms, antipsychotic medication often has little impact on the patient's ability to function independently in community, social, or occupational domains.12–14
The results of these treatment studies suggest that performance in the functional domains is independent of psychosis and tends to be medication resistant once illness has become chronic.
Such findings have converged to suggest that intervention should be initiated as early as possible, optimally prior to the onset of illness, at a point where social, academic, and occupational skills are acquired and solidified—typically considered to take place during adolescence and early adulthood.15
This has, in turn, highlighted the importance of the schizophrenia prodrome, a phase of rapid developmental change during which a range of early behavioral, cognitive, and clinical difficulties are hypothesized to emerge, many of which may still be remediable. Consistent with this view, Cornblatt et al16
have proposed a neurodevelopmental model in which impaired social and academic functioning during adolescence are considered to be core components of a biological susceptibility to schizophrenia and thus important targets of early intervention.
Although still a relatively new field, research has thus far demonstrated that the prodromal phase of illness is a clinical entity that is detected reliably17
and is associated with an elevated risk for subsequent schizophrenia (ranging from 20% to 40% within a 1- to 2-year follow-up period16,18–20
). Consistent with developments throughout the field of schizophrenia, prodromal researchers have only recently recognized the critical importance of the functional domains. As a result, there is a relative absence of functional measures specifically appropriate for the prodromal phase of illness. Research with chronic adult patients has tended to use a variety of measures that do not necessarily apply to the more subtle deficits characterizing prodromal youth. Of particular concern, the social functioning scales most commonly used in adult research tend not to address the unique social issues that occur in adolescence (eg, peer acceptance, dating, etc21
). Alternatively, the Global Assessment of Functioning Scale (GAF)22,23
, a widely used global scale, has been shown to have a number of psychometric problems24–26
and may be too confounded with psychiatric symptom severity to shed light on developmentally specific functioning.
A major example of the need for prodromal functional measures was provided during the construction of the North American Prodromal Longitudinal Study (NAPLS)–federated database.27
As part of the initial procedures followed to establish a common database across 8 prodromal studies, a survey (B. A.C. and A.A. data available on request) was made of functional measures used across participating sites. Major differences were found in virtually all aspects of the measures used. For example, type of instrument varied greatly, ranging from lengthy, detailed interviews28,29
and self-report measures30,31
to brief clinician-rated scales.32
In addition, these measures varied in targeted age range and domains covered, with measures developed for adults not typically appropriate for use with adolescents and vice versa. Measures developed for specific age ranges are particularly problematic for prodromal research, which covers a broad developmental period from early adolescence through young adulthood. As a result, to facilitate construction of the NAPLS database, 2 new functional measures were designed to meet the 5 criteria, including the need to (1) incorporate detailed anchors appropriate for capturing subtle prodromal difficulties, (2) cover the age range typical of the prodromal phase (from mid-adolescence through young adulthood), (3) disentangle social from role functioning domains, (4) detect changes in functioning over time, and (5) provide brief and easy to use clinician ratings.
The new measures, referred to as the Global Functioning: Social (GF: Social33
) and the Global Functioning: Role (GF: Role34
) scales, provide clinician rated single overall scores designed along the lines of the GAF Scale and the Social and Occupational Functioning Assessment Scale (SOFAS26
). However, the new GF scales differ substantially from both the GAF and the SOFAS in that they represent parallel (one targeting social, the other role) well-anchored scales that take age and phase of illness into account. In addition, the GF scales prevent combining unequal levels of functioning and avoid confounding functioning with psychiatric symptoms. Both scales can be used to summarize already existing information or as stand-alone interviews. The aims of the current study are to introduce these new measures and to report early findings resulting from their use in 2 ongoing prodromal studies. In the sections to follow, the interrater reliability of both the GF: Social and Role scales will be presented, and baseline levels of functioning, changes over time, and association with subsequently emerging psychosis will be described.