An important body of literature suggests that growing up in an urban environment during childhood is a risk factor for the later development of psychosis (1–4). Although various authors have proposed hypotheses to explain this correlation, the mechanisms involved in this phenomenon are still unknown. This is a matter of concern, considering the very high proportion of the world population living and growing in an urban environment, and this domain evidently deserves more research effort.

The urban environment is however more than a risk factor: it is also a place of enrichment, through interpersonal interactions, access to cultural events, and globally through socialization. Within the city and psychosis nexus, researchers in psychiatry have so far neglected to study the way patients experience the urban environment, how they use it, and to what degree they manage to gain access to it. This failure to address this aspect of the problem and the absence of studies doing so through the eyes of patients are limitations that need to be overcome. Indeed, the exploration of patients’ experience of the city environment may contribute not only to generate hypotheses to explain why growing up in an environment is a risk factor for later development of psychosis; it could also increase our understanding of the phenomenon of social withdrawal often described in psychosis patients.

In recent publications (5, 6), we have reported on a study that we are currently conducting in the context of a collaboration between psychiatrists, psychologists, geographers, and linguists. Through a combination of approaches, mixing exploratory focus groups with case managers, psychiatrists, and psychologists, interviews with patients, video-recorded go-along with a sample of 10 early psychosis (EP) patients, and a semi-structured interview with 20 EP patients, we managed to proceed to a first exploration of this domain.

In a first paper (5), we studied the way EP patients experience being in the city, with the aim to identify places of stress. This “unpacking of the city” revealed three ways to relate to the city among patients. While a first group tended to avoid the city center altogether, a second group used the city exclusively at certain times of the day and a third group reported having no problem in relation to the urban environment. When exploring sources of stress, patients mentioned four elements: a) crowd density; b) excess of stimuli, mainly auditory (sensory overload); c) situations of unavoidable social interactions; and d) hindrance to mobility (either by physical obstacles or by traffic).

In a second paper (6), we identified some of the strategies EP patients adopt in order to face these stressful elements, such as establishing sensory bubbles (through headphones or being accompanied by a friend), creating niches and breaks in the city (developing trajectories including parks or churches for example), or carefully programming trajectories in the city.

Based on these elements and on data stemming from the literature, we developed a questionnaire exploring the way EP patients use the city and the nature of their experience while being in an urban milieu. The aims of the study were to explore, in a large sample of EP patients, their pattern of use of the city, their perception of the various critical stressors that we identified through the previous abovementioned studies, and their sensitivity to various forms of stimuli. In addition, we wanted to assess the impact of the emergence of psychosis on these elements and to compare patients with a control group regarding these issues.

Although 400 patients were eligible at the time of the study, the questionnaire was sent to 305 of them. Ninety-five questionnaires were not sent because of the following reasons: patient moved out of Switzerland, diagnosis of organic psychosis, substance abuse as first-line diagnosis, patients whose address could not be found, and patients who had died. While 124 questionnaires were returned, 117 (38%) were usable and 7 were incomplete. Among the 220 students who attended third year of medical school at the time of the study, 205 (93%) returned their questionnaire. The characteristics of both groups are shown in Table 1 . Comparison of both groups revealed significant differences, with patients being significantly older than controls, and more likely to be male, to be a migrant, and to live independently. In addition, patients had moved houses more frequently and were less likely to have a regular activity at the time of the study.

There are three main findings in our study. First, the development of psychosis seems to influence city perception and the rate of avoidance of the city among patients. Second, patients’ tendency to avoid city center correlates with both problematic social interactions and stimuli perceived as unpleasant. Third, comparison between patients and controls reveals similarities regarding the type of urban space characterized as unpleasant, but patients seemed less likely to enjoy urban spaces considered as relaxing, suggesting a lower capacity to benefit from positive aspects of this environment.

Patients globally report that the onset of the illness induces an increase in city avoidance, a greater feeling of uneasiness with the crowd and towards eye contact, as well as a global higher sensitivity to stimuli. In addition, onset of psychosis correlates with a marked decrease in time spent outside of home and regarding openness to others. The fact that patients report a similar degree of negative perception of the crowd to controls as well as the feeling that this perception has become much worse since illness onset suggests that they may overestimate their status before the first episode. Nevertheless, our data strongly suggest that living in a city has become much more difficult for patients after psychosis onset. This globally suggests that emergence of psychosis restricts capacities to use urban space and to access the options it offers, due to various changes in the perception of the urban milieu. In turn, this may partly explain the withdrawal observed in patients, and it could therefore be useful to focus on this aspect through specific interventions, considering the potential self-perpetuating nature of city avoidance.

City avoidance is associated with two domains of difficulties. First, it is apparently linked to problematic social interactions, such as a decrease in openness to contact with others occurring after illness onset, and uneasiness with eye contact and proximity. Globally, these elements are probably linked to a mechanism of self-stigma, which may also constitute a target for psychological treatments through psychoeducation and work on self-esteem. Second, city avoidance is also linked to stimuli perceived as unpleasant, principally noise and physical contact. This may be explained by the phenomenon of aberrant salience (8), where all stimuli gain similar importance and contribute to the feeling of flooding, which is reported by a third of patients. There, again, some strategies might be developed to help patients cope with stimuli in order to regain some freedom.

Finally, we were not astonished that the comparison between patients and controls revealed that the former are more avoidant of the city and more disturbed by eye contact than the latter. It was more revealing to observe that while patients and controls are similar in their dislike of crowded places, patients were less likely to enjoy relaxing places such as the lakeshore or parks. This suggests that patients strongly experience the negative aspects of the city, but that they fail to benefit from the positive aspects of relaxing environment, a phenomenon that may stem from anhedonia and/or self-stigmatization. It is important to explore this issue in more depth, considering that recent studies have shown that exposure to natural features within the built environment may have a positive impact on mental well-being in a normal population (9). Conducting similar smartphone-based studies in patient samples would clarify if such a beneficial effect is also present after illness onset. In addition, while controls were more likely to report some aspects of the city as unpleasant (for example, they were more likely to perceive noise and smell as unpleasant), city avoidance was much less prevalent among them than among patients, which illustrates their greater capacity to cope with these perceptions and to access the city.

There are obvious limitations to this paper. First, it stems from a relatively small sample of patients and a low percentage of responses. Indeed, only 38% of patients responded to the questionnaire, which induces an important risk of non-response bias. Although this response rate is in keeping with surveys in metal health research (10), our results need replication in larger groups of patients with a similar profile. Second, the assessment of the impact of illness onset on city perception and city avoidance in patients is retrospective, and as mentioned above, this could bias the results through an overestimation of the way they felt before illness onset. A prospective study conducted among At Risk Mental State (ARMS) (11) subjects may overcome this issue, although we know that ARMS subjects can already display important functional impairment (12). Third, the control group is composed of medical students exclusively, a group that may not be representative of the general population. However, although medical students may, at first sight, look like a “super-healthy group,” various studies and review papers have recently shown that the prevalence of mental health issues among them is high and may even exceed the rate of the general population (13, 14), therefore limiting the impact of this potential bias. Fourth, while some patients who filled in the questionnaire were still in treatment and therefore would have been accessible for clinical assessment, a large number of subjects were not available for symptoms evaluation. Considering the potential impact of depressive, anxiety, as well as positive or negative symptoms on city avoidance, the absence of such assessment is a limitation of the study. However, in this paper, we explore city avoidance per se in a descriptive manner and the reasons subjects put forth to explain it but do not attempt to identify which illness dimensions may explain it, which may be the focus of later studies.

Despite these limitations, our study suggests that the development of psychosis has a great influence on the way EP patients perceive the city and on their capacity to feel at ease in the urban environment, leading to a high rate of city avoidance and decreased opportunity to interact with others. This aspect of the impact of the illness has not received the attention it deserves, although city avoidance can have a major influence on social relations and the recovery process. The development of strategies to help patients in this regard may have a significant effect on their recovery and therefore should be explored in more depth.

The local ethics committee (Commission cantonale (VD) d'éthique de la recherche sur l'être humain) approved the research protocol and all subjects provided informed consent to participate to the study.

PC, LA, ZC, PB, OS, DS, and PG have contributed to the design of the study, the grant application, the realization of the various stages of the research project, and the design of the questionnaire used in this part of the study. LA, ZC, and PB conducted the invoice of the questionnaire and the gathering of data. PG conducted the data analysis. PC and LA drafted the first version of the paper and all other co-authors contributed to the finalization of the paper.

This study was funded by the Swiss National Science Foundation (grant number CR13I1_153320).

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.