Aim Early detection of, and intervention for, psychosis during its prodromal phase has the potential to alter the course of the disease and has therefore become a major objective of modern clinical psychiatry. An increasing number of early detection and intervention services have been established in Europe and worldwide. This study aims to describe and evaluate an early detection and intervention service for children, adolescents and adults (FETZ Bern) aged from eight to 40 years with a population catchment area of 1.035 million in Bern, Switzerland. Methods Routine demographic, diagnostic and service usage data were collected upon admission to the service. Using a retrospective, descriptive and naturalistic study design, data was analysed for different age groups (children, adolescents and adults) and where available, outcome data after 12 and 24 months was evaluated. Results The FETZ Bern has received 827 referrals with full diagnostic data available for 353 patients. The majority of the assessed patients were young males. While 40% met criteria for a clinical high‐risk state of psychosis, 20% were diagnosed with fully manifest psychosis at time of admission, and another 40% had one or more non‐psychotic axis‐I diagnoses. Conclusions The FETZ Bern is the first early detection centre worldwide assessing children aged younger than 12 years, as well as adolescents and young adults in one service. Given that developmental peculiarities are important in understanding and ultimately treating psychosis, the FETZ Bern, with its emphasis on developmental peculiarities, should be considered as a model for other similar services.

Cocaine users consistently develop working memory (WM) impairments but the mediating molecular mechanisms are unknown so far. Recent evidence suggests that the serotonin (5-HT) system is altered by chronic cocaine use, while also being involved in WM processing. Thus, we investigated the effects of genetic variations impacting 5-HT activity and of peripheral 5-HT transporter (5-HTT) mRNA expression on WM performance in cocaine users and stimulant naive controls. Two hundred twenty participants (126 cocaine users, 94 controls) were assessed with visuospatial, spatial, and verbal WM tasks, genotyped for the length polymorphism in the promoter region of the 5-HTT (5-HTTLPR), the variable number of tandem repeats in the second intron of the 5-HTT (VNTR In2), two single-nucleotide polymorphisms (rs4570625 and rs1386497) in the tryptophan hydroxylase-2 (TPH2) gene and quantified for peripheral 5-HTT mRNA expression in whole-blood samples. Several significant gene × environment interactions between 5-HT genotypes and cocaine use on WM emerged: in cocaine users, the long/long (5-HTTLPR), 9+10/9+10 (VNTR In2) and C/C (TPH2 rs1386497) genotypes were risk alleles for WM impairments, whereas in healthy controls these polymorphisms were associated with improved WM performance. Analogously, high 5-HTT mRNA levels were associated with worse executive WM performance in cocaine users but with increased performance in controls. These gene × environment interactions suggest that the 5-HT system has an important role in the development of cognitive deficits in chronic cocaine users. Hence, pharmacological compounds targeting 5-HT neurotransmission might be promising for the treatment of cognitive deficits in cocaine dependence.

Among individuals with clinical high risk for psychosis (CHR), perceptive symptoms are more frequent but have less clinical significance in children/adolescents compared to adults. However, findings are based on clinical interviews relying on patient’s recall capacity. Ecological momentary assessment (EMA) can be used to explore experiences in real-time in the subject’s daily life. The aim of this study was to assess frequency and stability of (perceptive and non-perceptive) CHR symptoms and to explore potential age effects. EMA was used in a sample of an early detection for psychosis service in Bern, Switzerland (N = 66; 11–36 years). CHR symptoms were recorded in random time intervals for seven days: eight assessments per day per subject, minimum time between prompts set at 25 min. CHR symptoms were additionally assessed with semi-structured interviews including the ‘Structured Interview for Psychosis-Risk Syndromes’ and the ‘Schizophrenia Proneness Instruments’. Mixed-effects linear regression analysis on the frequency of CHR symptoms revealed a significant effect of age group, and the interaction CHR symptoms x age group for both perceptive and non-perceptive symptoms. Further, regarding stability of CHR symptoms, there was a significant effect of the interaction CHR symptoms x age group for perceptive symptoms only. Based on EMA, perceptive CHR symptoms were more frequently reported but less stable in children/adolescents compared with adults. Together with previous findings, our finding of higher instability/variability of perceptive symptoms in younger persons might suggest that with advancing age and more stability of CHR symptoms, clinical relevance (reduced psychosocial functioning) may increase.

Background: Depersonalization (DP) and derealization (DR) are symptoms of a disruption of perceptual integration leading to an altered quality of subjective experiences such as feelings of unreality and detachment from the self (DP) or the surroundings (DR). Both DP and DR often occur in concert with other symptoms, for example in subjects at clinical high-risk (CHR) for psychosis, but also appear isolated in the form of DP/DR disorder. Despite evidence that DP/DR causes immense distress, little is known about their neurobiological underpinnings. Therefore, we investigated the neural correlates of DP/ DR using pseudo-continuous arterial spin labeling MRI. Methods: We evaluated the frequency of DP/DR symptoms in a clinical sample (N = 217) of help-seeking individuals from the Early Detection and Intervention Centre for Mental Crisis (CHR, n = 97; clinical controls (CC), n = 91; and first-episode psychosis (FEP), n = 29). Further, in a subsample of those CHR subjects who underwent MRI, we investigated the resting-state regional cerebral blood flow (rCBF). Here, individuals with (n = 21) and without (n = 23) DP/DR were contrasted. Finally, rCBF was measured in a small independent second sample of patients with DP/DR disorder (n = 6) and healthy controls (HC, n = 6). Results: In the complete clinical sample, significantly higher frequency of DP/DR was found in CHR compared to CC (50.5 vs. 16.5%; c 2 (2) = 24.218, p ≤ 0.001, Cramer's V = 0.359) as well as in FEP compared to CC (37.9 vs. 16.5%; c 2 (2) = 5.960, p = 0.015,