Testing Liddle's three-syndrome model in families with schizophrenia

Abstract

While the symptoms of schizophrenia can be grouped into positive and negative syndromes, increasing evidence suggests that three clusters of symptoms are present. Liddle (1987a) described a three-syndrome model comprised of reality distortion, psychomotor poverty and disorganization symptom clusters. This model was assessed in the present study using a sample of 72 members of five families segregating schizophrenia. A wide range of psychopathology was present across a spectrum of diagnoses. Data on symptoms used in Liddle's model were derived from the Positive and Negative Syndrome Scale (PANSS) and a mental status examination. Factor analysis of the data indicated the presence of three clusters of symptoms. The psychomotor poverty or negative symptom cluster was confirmed in the familial sample. However, the other two factors differed somewhat from the Liddle model. Hallucinations, delusions, disorganized thinking and inappropriate affect formed one factor; suspiciousness and stereotyped thinking formed the other. These three symptom clusters may be comparable to the catatonic, hebephrenic and paranoid classical subtypes of schizophrenia. The implications of Liddle's model for genetic studies of schizophrenia require further investigation.

Childhood trauma and genetic factors in familial schizophrenia associated with the NOS1AP gene

“…The ascertainment and assessment procedures of the sample have been described elsewhere (Bassett et al, 1994; Brzustowicz et al, 2000; Wratten et al, 2009). Briefly, pedigrees were recruited for study because schizophrenia appeared to be segregating in a unilineal (one side of the family) dominant-like manner, and were selected if they had a proband and at least one other relative with schizophrenia or with schizoaffective disorder, and if multiple affected and unaffected members were willing to participate.…”

“…Briefly, pedigrees were recruited for study because schizophrenia appeared to be segregating in a unilineal (one side of the family) dominant-like manner, and were selected if they had a proband and at least one other relative with schizophrenia or with schizoaffective disorder, and if multiple affected and unaffected members were willing to participate. All participants were directly interviewed by a psychiatrist (ASB or EWC) using the Structured Clinical Interview for DSM-III-R (SCID-I), modified to obtain information on life history (including childhood and adolescence environmental exposures) and medical issues (AbdelMalik et al, 2003; Bassett et al, 1994). Collateral information, including extensive family history and medical records was also collected.…”

“…Samples with enhanced genetic homogeneity show increased power to detect effects of non-genetic factors (AbdelMalik et al, 2003). Following up on highly significant linkage of schizophrenia to a region on chromosome 1q22-q23 in a set of Canadian families with familial schizophrenia (Bassett et al, 1994; Brzustowicz et al, 2004), we have identified the A allele of the single nucleotide polymorphism (SNP) rs12742393 within the nitric oxide synthase 1 [neuronal] adaptor protein gene ( NOS1AP ) to be a risk allele associated with schizophrenia in this and an independent sample (Wratten et al, 2009). Two SNPs in strong marker to marker linkage disequilibrium with rs12742393 have shown significant association in schizophrenia in another independent sample (Kremeyer et al, 2009).…”

Component structure of the Positive And Negative Syndrome Scale (PANSS) in patients with recent-onset schizophrenia and spectrum disorders

“…All but one (Basset et al 1994) applied principal component analysis on data of patients with schizophrenia. Peralta and Cuesta (1994) found eight components, Kay and Sevy (1990) found seven components, and Bassett et al (1994) found three components. The other six studies found five components (Bell et al 1994;Kawasaki et al 1994;Lindenmayer et al 1994Lindenmayer et al , 1995Marder et al 1997;Higashima et al 1998).…”

Temporal lobe abnormalities in multigenerational families with schizophrenia

“…Parallel with efforts to isolate genes contributing to schizophrenia, research using schizophrenia pedigrees is providing important information about phenotypic aspects of the illness, including phenomenology (Bassett et al 1993(Bassett et al , 1994, neuropsychology (Roxborough et al 1993) and neurophysiology (Blackwood et al 1991;Waldo et al 1991). Neuroimaging studies of familial samples offer similar promise.…”