Background: The volume of research involving adjustment disorder (AD) is limited. The scientific neglect of AD seems to result from the inadequate operationalisation of AD in DSM-IV and ICD-10. The aims of the present proposal are to discuss the shortcomings of AD conceptualisations and to present recommendations for the future. Sampling and Methods: This conceptual paper is based on an iterative process of debate between the authors. Results: The current operational definition of AD is characterised by 3 main limitations: (1) the inadequately defined clinical significance criterion, (2) the relegation of AD behind other diagnoses and (3) the missed recognition of the importance of contextual factors, such that normal human adaptive processes might be pathologised. Furthermore, subtypes of AD lack operational clarity. Based on a discussion of the limitations, recommendations for DSM-V are presented, including the addition of new subtypes. Conclusions: The revision of AD criteria will reduce the likelihood of false-positive and false-negative diagnoses. These changes will enable the scientific exploration of this common and relevant disorder, and will make epidemiological studies, and ultimately service planning based on these, more reliable than at present.