ACQ_Vol_11_no_3_2009

Table 1. Number of adults (with SLI, PLI, or ASC) with mental health problems SLI (n = 18) PLI (n = 7)

ASC (n = 11)

Major depressive disorder

2

–

–

Major depressive disorder and

3 (Obsessive compulsive disorder,

–

3 (all three, generalised anxiety

anxiety disorder

social phobia, agoraphobia)

disorder)

Anxiety disorder

–

1 (generalised anxiety disorder)

1 (obsessive compulsive disorder)

study of PLI to date came from Bishop and Norbury (2002), who examined the clinical symptomatology of a cohort of children clinically diagnosed with either SLI, PLI or ASC. A number of interesting findings emerged. First, many children with a diagnosis of SLI were found to exhibit considerable pragmatic symptoms. Second, a minority of children with PLI or SLI showed autism-like characteristics, such as poor eye-contact and poor social awareness, but at sub-threshold levels (i.e., not reaching diagnostic criteria for ASC). Third, there were changes in symptomatology over time, so that some children meeting criteria for ASC at one age did no longer do so at a later age (and vice versa). Together these findings reinforced the notion that there was no sharp dividing line between SLI and PLI on one hand, and PLI and ASC on the other. Longer term outcomes Another way to determine whether PLI represents a valid diagnostic entity is by examining the longer-term outcomes of children with this diagnosis. If PLI is best viewed as a mild form of ASC, then we would expect the outcome of these individuals to more closely resemble those with ASC, rather than SLI. Recently, my colleagues and I at the University of Oxford investigated this question through a longitudinal study of children who took part in research during the 1980s and early 1990s. All children had received a clinical diagnosis of developmental language disorder and had been categorised at initial assessment as showing a profile consistent with either PLI or SLI. Despite exclusion of participants having a diagnosis of autism in childhood in the initial study, a small proportion of participants retrospectively met full criteria for autism. We have interpreted this finding as reflecting the broadening of autism diagnostic criteria from DSM-III (American Psychiatric Association, 1980) through to the most recent guidelines of DSM-IV-TR (American Psychiatric Association, 2000). These participants (n = 11) were pooled to form a separate ASC group, providing a useful comparison group for the SLI (n = 18) and PLI groups (n = 7). The participants were aged between 16 and 30 years of age. A detailed account of these findings have been reported elsewhere (Bishop, Whitehouse, Watt, & Line, 2008; Whitehouse, Line, Watt, & Bishop, 2009; Whitehouse, The first finding to emerge was that language and literacy profiles tended to persist into adulthood: at follow-up, the PLI group presented with predominantly pragmatic language deficits, the SLI group with considerable structural language and literacy impairments (as well as moderate difficulties with pragmatic language), and the ASC group with a combination of both structural and pragmatic language difficulties (Whitehouse, Line, et al., 2009). The psychosocial characteristics of the three groups of adults also demonstrated some separation in outcome. The adults with a diagnosis of SLI were not high-academic achievers, but Watt, Line & Bishop, 2009). Language outcomes

most had gained some form of vocational qualification. Many participants with SLI had difficulty finding stable employment, and those who were employed, were in professions that did not require high language and literacy skills (e.g., carpet fitter, cleaner, painter). A significant minority of participants in the SLI group had difficulty establishing friendships, and around one-half of the group had never had a romantic relationship of three months or more. The PLI group appeared more academically able than the SLI group and the majority of participants were employed in “skilled” professions (e.g., nurse, website designer, computer software designer). However, the PLI participants had substantially more difficulty in establishing and sustaining friendships and romantic relationships. The ASC group had significant difficulties with independence when assessed in adulthood, and many adults were living in supported accommodation. Most participants were working toward a vocational qualification, but few had ever obtained stable employment. No ASC participant reported having a close friendship or having experienced a romantic relationship. Psychosocial outcomes The psychosocial outcomes were in line with what we would predict from each group’s communicative profile. For example, there would be an expectation that individuals with structural language problems (i.e., those with SLI) would have particular difficulties with university education and associated employment. Similarly, it is reasonable to predict that individuals with pragmatic language problems (i.e., those with PLI or ASC) would have some difficulty in establishing and maintaining social relationships. However, it is important to note that there was a degree of variability in the language profiles of each group; some individuals with SLI demonstrated considerable pragmatic difficulties, while a minority of individuals with PLI had structural language deficits. Mental health outcomes One of the most striking findings of the study was the high incidence of mental health problems observed among adults with a history of developmental language problems. At follow-up, participants were asked whether they had ever been referred to a psychiatrist and, if so, what was the purpose and outcome of this referral. As seen in Table 1, mental health problems were reported in all three groups. Five of the 18 participants with an SLI diagnosis had received psychiatric treatment for an affective disturbance. Two of the three SLI participants with major depression and comorbid anxiety disorder had spent a period of time in a psychiatric hospital (one for two weeks and the other for two months). The third participant with this comorbidity had a history of violence towards his parents, and had repeatedly attempted suicide (the first attempt at age 10 years). Four ASC participants had been diagnosed with an anxiety disorder and two of these adults had spent periods as a resident at a psychiatric hospital. One PLI participant had received a diagnosis of generalised anxiety disorder, and had

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ACQ Volume 11, Number 3 2009

ACQ uiring knowledge in speech, language and hearing