Introduction
Aims of the study
Methods
Sample
Catchment area
Patient identification
Patient characteristics
Assessment of psychopathology
Symptom ratings
Selection of symptoms for entry into factor analysis
Kappa co-efficient Inter-rater reliability | Manic | Disorganised | Depressive | Delusional | Auditory hallucinations | Communality | |
---|---|---|---|---|---|---|---|
Bizarre behaviour | 0.87 | 0.33 | 0.49 | 0.07 | −0.20 | 0.20 | 0.43 |
Excessive activity | 0.84 | 0.86 | −0.05 | 0.03 | 0.22 | 0.02 | 0.79 |
Reckless activity | 0.62 | 0.80 | −0.04 | −0.08 | 0.16 | −0.05 | 0.66 |
Distractibility | 0.54 | 0.80 | 0.21 | −0.14 | 0.10 | 0.06 | 0.71 |
Reduced need for sleep | 0.76 | 0.77 | −0.27 | 0.20 | 0.19 | 0.20 | 0.78 |
Agitated behaviour | 0.61 | 0.76 | 0.01 | −0.44 | −0.15 | 0.12 | 0.80 |
Speech difficult to understand | 0.80 | 0.13 | 0.86 | 0.04 | 0.15 | −0.07 | 0.78 |
Positive formal thought disorder | 0.88 | −0.25 | 0.85 | 0.31 | 0.15 | −0.11 | 0.92 |
Pressured speech | 0.87 | 0.70 | 0.02 | 0.24 | 0.19 | −0.16 | 0.61 |
Thoughts racing | 0.78 | 0.77 | −0.07 | 0.14 | 0.10 | −0.02 | 0.63 |
Inappropriate affect | 0.91 | 0.02 | 0.63 | 0.02 | 0.16 | −0.01 | 0.42 |
Elated mood | 0.83 | 0.81 | 0.01 | 0.03 | 0.14 | −0.16 | 0.70 |
Irritable mood | 0.81 | 0.81 | −0.10 | −0.28 | 0.01 | −0.10 | 0.75 |
Dysphoria | 0.78 | 0.04 | −0.13 | −0.90 | 0.11 | −0.18 | 0.87 |
Suicidal ideation | 0.73 | −0.04 | −0.02 | −0.70 | −0.03 | −0.03 | 0.55 |
Persecutory delusions | 0.87 | −0.23 | −0.09 | −0.02 | −0.71 | −0.03 | 0.56 |
Well organised delusions | 0.69 | −0.25 | −0.27 | 0.12 | −0.81 | −0.14 | 0.82 |
Increased self-esteem | 0.76 | 0.73 | 0.17 | 0.09 | −0.01 | −0.22 | 0.61 |
Grandiose delusions | 0.69 | 0.67 | 0.29 | 0.10 | 0.19 | −0.03 | 0.57 |
Delusions of influence | 0.69 | −0.33 | 0.19 | 0.07 | −0.28 | −0.01 | 0.23 |
Bizarre delusions | 0.70 | −0.02 | 0.53 | −0.03 | 0.15 | 0.07 | 0.31 |
Widespread delusions | 0.86 | −0.17 | −0.02 | 0.07 | −0.73 | −0.02 | 0.57 |
Delusions of passivity | 0.88 | −0.16 | 0.39 | −0.10 | 0.08 | 0.17 | 0.22 |
Abusive/accusatory voices | 0.70 | −0.23 | −0.17 | −0.07 | 0.24 | 0.68 | 0.61 |
Other hallucinations | 0.67 | −0.25 | 0.17 | −0.33 | 0.15 | −0.24 | 0.28 |
Restricted or blunted affect | 0.70 | −0.54 | 0.33 | −0.16 | 0.17 | −0.11 | 0.46 |
Thought alienation | 0.81 | −0.15 | 0.34 | −0.16 | −0.19 | 0.18 | 0.20 |
Third person auditory hallucinations | 0.92 | −0.08 | −0.01 | 0.24 | 0.05 | 0.96 | 0.98 |
Reliability of opcrit ratings
Exploratory factor analysis
Statistical procedure for fitting the common factor model on the tetrachoric correlation matrix
Determination of the number of factors to extract
Factor rotation to aid interpretation
Examination of the stability of the factor solution
Factor score estimation and the distribution of dimensions within diagnostic classes
The relationship of dimensions and categories to known premorbid risk factors
Results
Reliability of the opcrit ratings
Factor structure
Manic | Disorganised | Depressive | Delusional | hallucinations | |
---|---|---|---|---|---|
Manic | 1.000 | ||||
Disorganised | −0.129 | 1.000 | |||
Depression | 0.207 | −0.323 | 1.000 | ||
Delusional | 0.339 | −0.259 | 0.275 | 1.000 | |
hallucinations | −0.296 | 0.320 | −0.362 | −0.292 | 1.000 |
Stability of factors across split halves of the sample
Opcrit generated diagnoses
Diagnosis | DSM-IV | ICD-10 | RDC | ||||||
---|---|---|---|---|---|---|---|---|---|
N (%) | Median age | Percent male |
N (%) | Median age | Percent male |
N (%) | Median age | Percent male | |
Schizophreniform | 89 (19.2) | 33 | 43.8 | – | – | ||||
Schizophrenia | 113 (24.4) | 33 | 54.0 | 304 (65.5) | 34 | 51 | 278 (59.9) | 36 | 49.3 |
Mania | 67 (14.4) | 39 | 38.8 | 51 (10.1) | 37 | 39.2 | 58 (12.5) | 40.5 | 37.9 |
Major Depression | 9 (2) | 42 | 11.1 | 4 (0.9) | 28.5 | 25 | 9 (1.9) | 37 | 33.3 |
Delusional disorder | 32 (6.9) | 72.5 | 31.3 | – | – | ||||
Unspecified | 140 (30.4) | 35.5 | 49.3 | 104 (22.4) | 28.5 | 32.7 | 63 (13.8) | 37 | 45.3 |
Schizoaffective | 3 (0.7) | 31 | 33.3 | 1 (0.2) | – | – | 53 (11.4) | 33 | 35.9 |
Not classified | 11 (2.4) | 65 | 27.3 | – | 2 (0.43) | 23 | 0 |
Distribution of dimensions within dsm classification system
Manic N (%) | Disorganised N (%) | Depression N (%) | Delusional N (%) | Hallucinations N (%) | |
---|---|---|---|---|---|
Schizophrenia | 21 (19) | 57 (50) | 26 (23) | 25 (22) | 39 (35) |
Schizophreniform | 21 (24) | 42 (47) | 32 (36) | 23 (26) | 42 (47) |
Manic | 62 (93) | 16 (24) | 17 (67) | 47 (70) | 22 (33) |
Major depression | 3 (30) | 1 (10) | 10 (100) | 5 (50) | 3 (30) |
Delusional disorder | 1 (3) | 0 | 4 (13) | 4 (13) | 1 (3) |
Unspecified | 44 (31) | 38 (27) | 38 (27) | 38 (27) | 44 (31) |
Association of dimensions to known premorbid risk factors
Dependent variable in logistic/linear model | Comparison of full model with model constrained by dropping the categorical diagnoses | Comparison of full model with model constrained by dropping the dimensions | ||
---|---|---|---|---|
Premorbid risk factor | Likelihood ratio statistic |
p-value | Likelihood ratio statistic |
p-value |
Gender | 10.68 | 0.06 | 4.44 | 0.49 |
Age at presentation | 22.78 | <0.001 | 86.14 | <0.001 |
Single at presentation | 8.20 | 0.15 | 15.38 | <0.01 |
Unemployed at presentation | 13.63 | 0.02 | 10.25 | 0.07 |
Poor work adjustment | 15.61 | <0.01 | 15.35 | <0.001 |
Poor social adjustment | 19.25 | <0.001 | 2.59 | 0.76 |
Alcohol/drugs misuse | 6.06 | 0.19 | 18.92 | 0.002 |
Psychosocial stressor | 12.90 | 0.02 | 18.07 | 0.002 |
Family History schizophrenia | 6.25 | 0.28 | 6.37 | 0.27 |
Family psychiatric history | 1.84 | 0.76 | 8.67 | 0.12 |