Ordinary employment, from the vulnerability-stress model, is believed to trigger relapses in people with long-term mental disorders when subjected to demanding work environments. To test the accuracy of this hypothesis, different databases between 1998 and 2019 (May) were consulted, using various key words. Randomized Clinical Trials (RCTs) that analyzed non-vocational outcomes related to symptomatology and hospitalizations in the Individual Placement and Support (IPS) strategy with severe mental disorders were specifically reviewed. A total of 383 references were reviewed, 26 were selected and 18 were included. Of the selected studies the follow-up period is between 12 months and 24 months for the most part. Samples usually range from 100-200 participants but there are studies with larger samples, one study with over 2059 participants. The most commonly used outcome is admissions and relapses, the most commonly used being days of hospitalization. The most widely used scales were on overall functioning, GAF and to measure relapse, PANNS and BPRS. Competitive employment was found not to cause relapses or hospitalisations, and long-term employment seemed to contribute to a favourable clinical evolution, although the degree of impact on the health status has yet to be proven.