S228 Abstracts of the 4th Biennial Schizophrenia International Research Conference / Schizophrenia Research 153, Supplement 1 (2014) S1–S384

Poster #M105

SCHIZOTAXIA REDUX

Vaughan J. Carr1, Jessica Bowen1, Melissa J. Green1,2

1University of New South Wales; 2School of Psychiatry

Background: In 1962 Paul Meehl introduced the term schizotaxia to re-

fer to a genetically determined neural integrative defect predisposing to

schizophrenia. On interaction with the social environment and “polygenic

potentiators”, schizotaxia was proposed to lead to a pattern of psycholog-

ical organisation called schizotypy, as a necessary precondition for “true”

schizophrenia (as opposed to phenocopies emerging via alternative means).

Meehl’s schizotype was characterised by “cognitive slippage”, interpersonal

aversiveness, anhedonia, and ambivalence, with neurological soft signs

thought to be caused by the core neural integrative defect. The concept

of schizotaxia is difficult to define, and its manifestations in the form

of schizotypy similarly difficult to operationalize (but it is not equivalent

to DSM schizotypal personality, nor conceptualizations based on positive

psychotic-like experiences). Using Meehl’s descriptions and attempts by

others to measure schizotaxia, we sought to identify individuals with these

characteristics and determine the utility of this concept for future study in

a large sample of healthy individuals and schizophrenia patients from the

Australian Schizophrenia Research Bank (ASRB).

Methods: Participants were 659 healthy controls and 617 schizophrenia

or schizoaffective disorder cases in the ASRB. A series of Grade of Mem-

bership (GoM) analyses were conducted separately for healthy control and

case samples, using putative indicators of schizotaxia including specific

neurocognitive measures (attention, immediate memory, executive func-

tion), self-reported asociality and constricted affect (from the Schizotypal

Personality Questionnaire), and neurological soft signs (NSS). The emergent

“pure types” were compared in terms of other cognitive, personality, and

socio-demographic features, as well as illness-related variables for cases.

Results: Each GoM analysis produced similar three-type solutions: the

first subtype was relatively unimpaired on all variables, the second was

characterised by predominant NSS and mild executive dysfunction. The

third subtype, arguably reflecting “schizotaxia”, was characterised by sig-

nificantly impaired cognitive functioning, asociality, constricted affect (in

controls), and poor NSS sensory integration (in controls) or motor control

(in SZ). Post-GoM comparison of resulting subtypes reported high levels

of social anxiety, suspiciousness, cognitive-perceptual schizotypal features,

and a greater level of childhood adversity in schizotaxic controls (5.7% of

the sample). In contrast, SZ cases belonging to the putative schizotaxic type

(29.8% of cases) were characterized by more severe negative symptoms,

and a lower level of childhood adversity.

Discussion: These findings provide preliminary evidence supporting a pu-

tative “schizotaxic” profile evident in both clinical and non-clinical groups,

in accord with a population base-rate predicted by Meehl’s model. Future

study of potential neurobiological differentiation of the schizotaxic subtype

is warranted.

Poster #M106

THE CLINICAL OVERLAP BETWEEN AUTISM AND PSYCHOSIS

Katie E. Chisholm1, Stephen Wood1, Renate L. Reniers1, Matthew Broome2,

Ashleigh Lin1

1University of Birmingham; 2University of Oxford

Background: Schizophrenia spectrum disorders (SSD) and autism spectrum

disorders (ASD), currently conceptualised as separate, have been reported to

co-occur at elevated rates. Additionally, the diagnostic criteria of each dis-

order have areas of overlap and recent research suggests that the disorders

share multiple phenotypic similarities. As SSD and ASD are both thought

to exist on extended phenotypic continua, it is important to consider not

only co-occurrence at the diagnostic level, but also to investigate evidence

of overlap in traits. Research of this type is underrepresented in the field.

Investigation at the trait level will aid the development of a fundamental

understanding of the disorders and their joint impact on quality of life and

functioning.

Methods: Young people presenting with a first episode of psychosis to

Early Intervention Services in Birmingham were invited to take part in the

research. The positive and negative symptom scale (PANSS) was used to

measure positive, negative, and general symptoms of psychosis, and the

schizotypal personality questionnaire (SPQ) used to measure underlying

schizotypal traits. The Autism Quotient (AQ) was used to measure traits of

ASD. The authors of the AQ suggest that scores of above 32, although not

diagnostic, may indicate that ASD is present, and that an individual with

ASD is unlikely to score less than 26.

Results: Preliminary results from 32 participants suggest that traits of ASD

are found at elevated rates in individuals experiencing a first episode of

psychosis. Participants (24 male) were aged between 18 and 36 (mean

age 26). Of these initial 32 participants, 4 participants scored higher than

26 on the AQ, including 3 scoring higher than 32. Associations between

current psychotic symptoms, schizotypal personality, and autism traits

were examined. ASD traits were found to have a moderate to strong

positive correlation with both state (PANSS) and trait (SPQ) measures of

SSD. In particular, strong positive correlations were found between the SPQ

subscale of interpersonal deficit and AQ subscales, and between general

current symptoms and AQ subscales. Traits of ASD and SSD, as well as

current symptoms of psychosis, also had significant negative correlations

with participants’ quality of life and current levels of functioning. In par-

ticular, current general symptoms of psychosis were highly correlated with

overall quality of life and functioning, as well as the quality of life subscale

of engagement with life. Similarly current negative symptoms of psychosis

showed strong correlations with overall quality of life and engagement in

life. In addition, current positive symptoms of psychosis, total AQ score,

and the schizotypal subscale of interpersonal deficits were negatively cor-

related with quality of life and functioning. Data will be collected from 100

participants with first episode psychosis. With the full dataset, we will also

discuss the association between traits of ASD and childhood trauma, as well

as premorbid adjustment.

Discussion: This remains an important topic for investigation to improve

understanding of areas of dissociation and overlap between the disorders.

We will present a more definitive conclusion with a larger data set.

Poster #M107

CLINICAL IMPLICATIONS OF SCREENING FOR NMDA ENCEPHALITIS IN

FIRST EPISODE PSYCHOSIS

Eric Kelleher1,2, Colin Doherty3, Aiden Corvin1

1Trinity College Dublin; 2St James’ Hospital, Dublin; 3Department of

Neurology, St James’ Hospital, Dublin

Background: The diagnosis of Schizophrenia is based clinically on charac-

teristic positive symptoms (e.g. delusions, hallucinations), negative symp-

toms and social deterioration. Identifying particular aetiologies in specific

patient groups may be important in advancing diagnostics and therapeu-

tics. Anti-N-Methyl-D-Aspartate (NMDA) encephalitis is associated with

auto-antibodies to the NR1 hetromere of the NMDA Receptor. Based on

recent literature, Anti-NMDA receptor encephalitis could be implicated in

approximately 10% of psychotic presentations. Patients with florid NMDA

encephalitis e.g. those with initial psychotic symptoms followed by subse-

quent catatonia, seizures and autonomic dysfunction are usually referred

for treatment with immunotherapy. However mild or incomplete forms of

the disorder could potentially occur with psychiatric features in isolation.

Electroencephalogram (EEG) and Magnetic Resonance Imaging (MRI) of

the brain can aid diagnosis. The aim of this ongoing study is to screen a

prospective sample of patients with a first episode of psychosis presenting

to our service for NMDA antibodies to establish the prevalence in this

group. For identified cases, we aim to collaborate with neurology colleagues

on treatment decisions and clinical care pathways. We report findings of

the first 9 months of the study.

Methods: Following ethical approval, we invited psychiatry teams within

the defined catchment area of our service to refer all patients with a first

episode psychosis who met entry criteria from January 2013. Recruitment

involved a structured clinical interview for DSM-IV (SCID) diagnosis which

incorporated the Scale for the Assessment of Positive Symptoms (SAPS)

and Scale for the Assessment of Negative Symptoms (SANS). Phlebotomy

for a serum sample for NMDA antibodies was also taken and sent to John

Radcliffe Hospital, Oxford, a tertiary referral centre for the diagnosis of

immunological disorders.

Results: 4/31 (13%) samples were identified as being NMDA positive. Av-

erage age of NMDA-positive cases was older than other first-episode cases