ACQ_Vol_11_no_3

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ACQ

Volume 11, Number 3 2009

ACQ

uiring knowledge in speech, language and hearing

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

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,

Watt, Line & Bishop, 2009).

Language outcomes

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

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

–

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)