The absence of melancholic features might also be of assistance in distinguishing those with adjustment disorder from those with a depressive episode or major depression. Yates et al (2004) examined a group of patients with major depression with and without physical illness. Patients with physical illness were less likely to display melancholic features, raising the possibility that the greater the role of environmental factors, the less likely are the typical melancholic symptoms to be present. Since environmental factors are prominent in adjustment disorder, it is possible that these symptoms might help distinguish individuals with adjustment disorder from those with more biologically determined depression. Only further studies will demonstrate whether these symptoms have suf cient speci city. This has led to recommendations (Baumeister 2009) that this should be encapsulated in the revisions for DSM-5 and ICD-11.
Suicidal behaviour is common in people with adjustment disorder. As many as 25% of adolescents with a diagnosis of adjustment disorder engage in this behaviour (Pelkonen 2005), and this rises to 60% among adults (Kryzhanovskaya 2001). Moreover, suicidal behaviour emerges several months earlier in patients with adjustment disorder in comparison with major depression (