Background
Methods
Subjects
Clinical assessments
Assessment of symptom dimensions and OCCPI ratings
Data analyses
Principal component analysis (PCA)
Principal component | Affective | Reality distortion | Disorganised/negative | Motor |
---|---|---|---|---|
Loss of energy/tiredness |
0.84
| |||
Loss of pleasure |
0.83
| |||
Poor concentration |
0.82
| |||
Slowed activity |
0.68
| |||
Initial insomnia |
0.63
| |||
Poor appetite |
0.62
| |||
Dysphoria |
0.6
| |||
Excessive self-reproach |
0.59
| |||
Increased self esteem |
0.48
| |||
Irritable mood |
0.47
| |||
Suicidal ideation |
0.4
| |||
Primary delusional perception |
0.76
| |||
Other primary delusions |
0.66
| |||
Delusions of passivity |
0.62
| |||
Bizarre delusions |
0.61
| |||
Auditory hallucinationsa
|
0.58
| |||
Clérambault–Kandinsky complexb
|
0.57
| |||
Non-affective hallucination of any type |
0.54
| |||
Delusions of influence |
0.53
| |||
Grandiose delusions |
0.39
| |||
Inappropriate affect |
0.67
| |||
Restricted/ blunted affect |
0.66
| |||
Negative formal thought disorder |
0.56
| |||
Bizarre behaviour |
0.48
| |||
Positive formal thought disorderc
|
0.44
| |||
Delusions of guilt |
0.56
| |||
Agitated activity |
0.31
| |||
Catatonia |
−0.62
|
Statistical methods
Results
Sample characteristics
Pre-onset CUD vs. “no pre-onset” CUD: categorical variables
Total sample | SZ with no pre-onset CUD | SZ with pre-onset CUD |
p
| |
---|---|---|---|---|
Number of subjects | 171 | 140 | 31 | – |
Male [n (%)] | 114 (67.1%) |
84 (60.4%)
|
30 (96.8%)
|
<0.001
|
Mean age at assessment [years (SD)] | 34.0 (11.7) |
35.4 (12.1)
|
27.6 (6.8)
|
0.001
|
Mean age at onset [years (SD)] | 23.7 (7.9) | 24.4 (8.5) | 20.9 (3.4) | 0.027 |
Mean age at cannabis use onset [years (SD)] | – | – | 18.3 (3.7) | – |
Mean duration of the illness [years (SD)] | 11.5 (11.1) | 12.6 (11.7) | 6.7 (6.7) | 0.007 |
Mean number of hospital admissions/illness duration | 0.6 (0.7) | 0.6 (0.8) | 0.6 (0.4) | 0.82 |
Personal history of suicide attempts [n (%)] | 75 (45.5%) | 65 (47.8%) | 10 (34.5%) | 0.19 |
Family history of schizophrenia [n (%)] | 16 (10.2%) | 12 (9.4%) | 4 (13.3%) | 0.53 |
Family history of mood disorders [n (%)] | 66 (44.0%) | 56 (46.3%) | 10 (34.5%) | 0.25 |
Family history of suicide attempts [n (%)] | 26 (17.6%) | 23 (19.3%) | 3 (10.3%) | 0.25 |
Pre-onset CUD vs. “no pre-onset” CUD: symptom dimension features
Logistic regressions
B
| SE |
df
|
p
| Odds ratio | 95% Confidence interval for odds ratio | ||
---|---|---|---|---|---|---|---|
Lower | Upper | ||||||
Sexa
| 2.76 | 1.04 | 1 |
0.008
|
15.76
| 2.06 | 120.43 |
Age at assessment | −0.06 | 0.02 | 1 | 0.007 | 0.94 | 0.89 | 0.98 |
B
| SE |
df
|
p
| Odds ratio | 95% Confidence interval for odds ratio | ||
---|---|---|---|---|---|---|---|
Lower | Upper | ||||||
Categorical variables | |||||||
Sexa
| 2.79 | 1.05 | 1 |
0.008
|
16.29
| 2.09 | 126.75 |
Age at assessment | −0.07 | 0.03 | 1 | 0.008 | 0.93 | 0.89 | 0.98 |
Factor scores | |||||||
Affective | 0.06 | 0.08 | 1 | 0.47 | 1.06 | 0.91 | 1.14 |
Reality distortion | 0.09 | 0.09 | 1 | 0.31 | 1.10 | 0.92 | 1.32 |
Disorganised/negative | 0.02 | 0.17 | 1 | 0.91 | 1.02 | 0.72 | 1.43 |
Motor | 0.07 | 0.24 | 1 | 0.77 | 1.07 | 0.66 | 1.73 |