Comorbid substance abuse in first-episode schizophrenia: effects on cognition and psychopathology in the EUFEST study.

UNLABELLED: Studies and meta-analyses investigating the influence of substance use disorder (SUD) (substance abuse or dependence) on psychopathology and neurocognitive function in schizophrenia patients have revealed controversial results. Most studies did only have small samples and did not focus exclusively on first-episode schizophrenia patients. METHOD: In a post-hoc analysis of the European First Episode Schizophrenia Trial (EUFEST) psychopathology and cognitive performances of patients with (FE-SUD, N=119, consisting of N=88 patients with persisting SUD at baseline and N=31 patients with previous SUD) and without SUD (FE-non-SUD, N=204) were compared at baseline and 6 months follow-up. Neurocognitive assessment included the Rey Auditory Verbal Learning Test (RAVLT); Trail Making Tests A and B (TMT), Purdue Pegboard and Digit-Symbol Coding. RESULTS: In total 31.1% of patients reported SUD, and 22.2% of patients used cannabis. There were no significant differences between patients with and without SUD concerning PANSS scores, extrapyramidal motor symptoms or neurocognitive measures except better performance in psychomotor speed (TMT-A, p=0.033, Cohen's d=0.26) in patients with SUD at 6 months follow-up. Interestingly, SUD patients with ongoing substance use at follow-up showed elevated positive symptoms (PANSS positive score, p=0.008, Cohen's d=0.84) compared to those who abstained. PANSS scores at baseline were increased in patients with an onset of SUD before the age of 16 years. In addition we found a correlation between longer duration of cannabis use and higher cognitive performance as well as reduced symptom improvement and more extrapyramidal motor symptoms in patients with higher frequency of cannabis consumption. CONCLUSIONS: FE-SUD and FE-non-SUD show similar psychopathology and neuropsychological performances at baseline and during the first 6 months of antipsychotic treatment.

Familial sinistrality and handedness in patients with first episode schizophrenia: the EUFEST study.

The population with schizophrenia is characterised by a leftward shift in handedness-sinistrality. However, findings are inconsistent in chronic patients, and familial sinistrality (FS), defined as the presence of left-handed close relatives, might contribute to the discrepancies. Therefore the aim of this study was to investigate the strength of manual lateralisation in patients with first episode schizophrenia, taking into account familial sinistrality. The Edinburgh Inventory (EI) allowed us to categorise 179 patients from the EUFEST study and 189 controls presenting "strong handedness" (SH: EI absolute value between ∣81∣ and ∣100∣) or "weak-handedness" (WH: EI value between -80 and +80). The nominal logistic regression did not show an FS effect, but a nearly significant interaction between illness and FS (p =.07). There were fewer participants without FS presenting SH among patients (99/151: 65.6%) than among controls (134/164: 81.7%, p =.001). In contrast, the number of participants with FS presenting SH was similar between controls (68%) and patients (75%, p =.57). The presence of left-handed relatives (FS + ) tended to reduce manual lateralisation, but only in controls. This supports the notion that reduced manual lateralisation in schizophrenia is related to the illness rather than to familial left-handedness.