POPULATION SAMPLES

Two population samples o f unrelated schizophrenic patients and control subjects were used for the research presented in this thesis. One population sample was drawn from East Anglia (EA) and the other from East Yorkshire (EY). The majority o f individuals constituting the EA population sample were drawn from two rural areas, Cambridge and Norfolk. The majority o f individuals constituting the EY population sample were drawn from EY. Informed consent was obtained from all patients, after which information regarding the patients were gathered from staff, relatives and case notes. The patients from the two population sample were then assessed for various symptoms and movement disorders by the clinicians. The EY population sample was obtained for a replication study o f the association between GAG repeat size and schizophrenia. Consequently, the patients were not scored for all the symptoms ratings and movement disorders as was performed for the patients from EA. The patient and control subjects were also matched for age and gender. EDTA anticoagulated venous blood samples o f

10-20ml were drawn from each individual and the DNA was extracted from 10ml o f whole blood using the Nucleon II™ kit (Scotlab) and dissolved in 0.1ml o f sterile distilled water.

2.2.1 East Anglia population sample

The EA population sample, all o f European descent, includes a large proportion o f

Methods and Materials individuals whose families may have been settled in this area for many generations w ith limited immigration. At the time the population sample was collected from rural areas o f EA region, according to the Office o f National Statistics, 95.8% o f Caucasians from the EA region were bom in UK, 0.96% were bom in Ireland and 3.3% were bom in other European countries. Eighty four unrelated patients with schizophrenia (46 males and 38 females) were recmited from the rehabilitation and acute services at Fulboum Hospital, Cambridge, EA. Subjects were interviewed using the Present State Examination (Wing et a i, 1974) and diagnosis made according to the DSMIIIR criteria to assess recent and chronic psychopathology. Forty-nine patients were taking clozapine at the time the blood samples were collected. Patients were categorised clinically as responding or non­ responding to clozapine. The patients were then assessed for the following:

(i) Negative symptoms (see section 1.2.2) were rated using the High Royds Evaluation o f Negativity, HENs scale (Mortimer et ah, 1989). The mean negative symptoms score was 12.4 ± 4.2, with a range from 0 to 21.

(ii) The presence and severity o f movement disorders using the Modified Rogers Scale (Lund et a l, 1991). This scale rates movement disorders phenomenologically, giving a global rating which includes both dyskinetic, positive and negative catatonic phenomena. The global scores o f our patients had a mean o f 3.7 ± 3.6, with a range from 0 to 17. (iii) Catatonia (see section 1.2.2), a disorder o f willed movement and can be either positive (for example repetitive manneristic movements) or negative (for example posturing, waxy flexibility). Scores ranged from 0 to 10, with a mean score o f 1.7 ± 2.3. (iv) Tardive dyskinesia scores, on a separate sub-scale, measures repetitive, involuntary movements, sometimes caused by medication but sometimes oecurring on their own. Scores ranged from 0 to 40, with a mean score o f 6.4 ± 6.7.

(v) AAO o f illness was defined as the age at which psychotic symptoms were first documented or the age o f first psychiatric admission, whichever was earlier. Although the method o f rating was consistent, a degree o f uncertainity remained for some subjects with little insight and a long history o f vague behavioural disturbance before admission. Any inaccuracy would tend to be in the direction o f over-estimation o f AAO. The mean AAO was 23.5 ± 6.4 years, with a range from age 16 to 49 years.

(vi) A positive family history was defined for the purposes o f analysis, as the presence o f a first- or second-degree relative with schizophrenia or schizoaffective disorder, as in previous positive reports (Nimgaonkar et a l, 1993). By this definition, 17 patients had a

Methods and Materials positive family history.

(vii) Patients were considered to have disorganisation syndrome (see section 1.2.2) if they displayed any o f the following: incoherence o f speech, poverty o f content o f speech, distractibility, or incongruous affect. This was measured on a categorical scale o f 1 if patients had the syndrome and 0 if it was absent in patients. Forty-four o f the 84 patients showed disorganisation syndrome.

(viii) Reality distortion syndrome measures positive symptoms (see section 1.2.1) and the positive symptoms are divided into two types, either the integrative or disintegrative. Integrative reality distortion syndrome was considered present if the patient had any o f the following: delusions o f reference, delusions o f persecution or grandiose delusions. Disintegrative reality distortion syndrome was considered present if the patients had any o f the following: passivity phenomena (delusions o f being controlled), thought alienation (for example, having thoughts taken out o f one’s mind), primary delusions (characteristic o f schizophrenia), third-person auditory hallucinations or sexual or bizarre delusions. These two types were also measured on a categorical scale o f 1 if present and 0 if absent. Fifty seven patients showed reality distortion syndrome.

(ix) Outcome ratings measures the recovery rate o f patients (McKenna, 1994). It is measured on an ordinal but not quantitative scale o f 0 to 3. 0 - complete recovery, meaning no active symptoms, no signs o f deterioration, working at previous level, no or minimal social impairment, only one episode o f illness. 1 - social recovery, meaning no or minimal activé symptoms, minimal signs o f deterioration, for example working, no severe social impairment, may have been more than one episode o f illness. 2 - improved: ongoing active symptoms and/ or obvious signs o f deterioration, may or may not be able to work at lower level, out o f hospital. 3 - unimproved or worse, meaning moderate or severe ongoing active symptoms and signs o f deterioration, unable to work, may or may not require long-term hospitalisation.

(x) The Parkinsonism score measures extrapyramidal features (that is, basal ganglia, red nucleus and a number o f other pathways involved in motor control and regulation). It measures lack o f movement, rigidity, tremor, stiffness o f gait, lack o f eye blink response and other features commonly observed in both idiopathic and drug-induced Parkinson’s disease. Parkinsonian features are only observed in patients on neuroleptics or have coincident idiopathic Parkinson’s disease. However, the vulnerability to extrapyramidal side effects varies from patient to patient, for reasons as yet un-elucidated. High score means worse movement disorder. The mean score was 1.0 + 2.1, with a range o f 0 to 13.

Methods and Materials Seventy-nine control subjects (40 males and 37 females) were recruited from the oral surgery and ophthalmology wards and clinics in Addenbrooke’s Hospital, Cambridge. All control subjects included in the studies presented in this thesis were Caucasians. A brief interview was administered to detect a personal or family history of major depression, bipolar affective disorder, schizophrenia or schizoaffective disorder. No control subjects showed any overt movement disorder. The mean age o f control subjects (41.7 years) did not differ significantly from that o f patients (43.8 years). There was no significant differences in gender distribution as well.

2.2.2 East Yorkshire population sample

The EY population sample, also o f European descent, includes a large proportion o f individuals whose families may have been settled in this area for many generations with limited immigration. At the time the population sample was collected 98.2% o f Caucasians from the EY region were bom in UK, 0.57% were bom in Ireland and 1.23% were bom in other European countries (Office o f National Statistics).

Seventy-two unrelated Caucasian schizophrenic patients (40 males and 29 females + 3 for whom information regarding sex was not given) were recmited from the psychiatric outpatient clinic based at De La Pole Hospital, Hull, EY. Only six patients are on clozapine treatment. Three o f the patients have responded excellently to treatment and one has responded moderately. For two patients the response to treatment has not been evaluated by the consultant. The patients were assessed for the following;

(i) The patients were diagnosed as suffering from one o f the following schizophrenia subtypes (see section 1.3) using the DSMIV code: paranoid type, disorganised type, catatonic type, undifferentiated (the essential features are prominent psychotic symptoms such as delusions, hallucinations, incoherence or grossly disorganised behaviour, that cannot be classified in any other subtype category) type and residual type (emotional blunting, social withdrawal, eccentric behaviour, illogical thinking and mild loosening o f associations are common but with the absence o f prominent delusions, hallucinations, incoherence or grossly disorganised behaviour). 38, 15, 1, 5 and 9 schizophrenic patients were diagnosed as suffering from the paranoid type, disorganised type, catatonia type, undifferentiated type and residual type respectively. The schizophrenia subtype o f four patients had not been determined at the time the blood

Methods and Materials samples were collected.

(ii) Negative symptoms were rated using the HENs scale. The mean negative sym ptom s score was 10.06, with a range o f 0 to 2 2.

(iii) The Global assessment scale (GAS) was used to assess the overall severity o f the disease. A mean score was 39.9, with a range o f 20 to 85. Higher the score, the severe the disease.

(iv) Basic psychological functions were assessed using the M ini-M ental State Examination (MMSE, McKenna, 1994). The mean MMSE score was 22.4 with a range o f 2 to 30.

(v) The AAO o f illness was determined as performed for the EA patients. The mean AAO was 19.75, with a range o f 9 to 47 years. AAO as young as 9 years was determined based on the onset o f psychological problems that preceded schizophrenia, for example, depression.

Eighty-five unrelated Caucasian control subjects (38 males and 47 females) were recruited from the Hull Royal Infirmary, the majority o f control subjects were diabetic patients. None o f the control subjects suffered or had a family history o f major depression, bipolar affective disorder, schizophrenia or schizoaffective disorder. The mean age o f control subjects (46.6 years) did not differ significantly from that o f patients (46.0 years). There was no significant differences in gender distribution as well.