One reviewer has commented on the difficulty of clarifying the core characteristics of and differences between atypical attachment styles and ways of categorizing more severe disorders of attachment.As of 2010, the American Psychiatric Association has proposed to redefine RAD into two distinct disorders in the DSM-V. Corresponding with the inhibited type, one disorder will be reclassified as Reactive Attachment Disorder of Infancy and Early Childhood.In regards to pathogenic care, or the type of care in which these behaviors are present, a new criterion for Disinhibited Social Engagement Disorder now includes chronically harsh punishment or other types of severely inept caregiving. Relating to pathogenic care for both proposed disorders, a new criterion is rearing in atypical environments such as institutions with high child/caregiver ratios that cut down on opportunities to form attachments with a caregiver. Differential diagnosis
The diagnostic complexities of RAD mean that careful diagnostic evaluation by a trained mental health expert with particular expertise in differential diagnosis is considered essential. Several other disorders, such as conduct disorders, oppositional defiant disorder, anxiety disorders, post traumatic stress disorder and social phobia share many symptoms and are often comorbid with or confused with RAD, leading to over and under diagnosis. RAD can also be confused with neuropsychiatric disorders such as autism, pervasive developmental disorder, childhood schizophrenia and some genetic syndromes. Infants with this disorder can be distinguished from those with organic illness by their rapid physical improvement after hospitalization. Autistic children are likely to be of normal size and weight and often exhibit a degree of intellectual disability.
Such infants do not seek or accept comfort at times of threat, alarm or distress, thus failing to maintain "proximity", an essential element of attachment behavior. The disinhibited form shows diffuse attachments as manifest by indiscriminate sociability with marked inability to exhibit appropriate selective attachments (e.g., excessive familiarity with relative strangers or lack of selectivity in choice of attachment figures). There is therefore a lack of "specificity" of attachment figure, the second basic element of attachment behavior. The ICD-10 descriptions are comparable save that ICD-10 includes in its description several elements not included in DSM-IV-TR as follows:

abuse, (psychological or physical), in addition to neglect;
associated emotional disturbance;
poor social interaction with peers, aggression towards self and others, misery, and growth failure in some cases (inhibited form only);
evidence of capacity for social reciprocity and responsiveness as shown by elements of normal social relatedness in interactions with appropriately responsive, non-deviant adults (disinhibited form only).The first of these is somewhat controversial, being a commission rather than omission and because abuse in and of itself does not lead to attachment disorder. The inhibited form has a greater tendency to ameliorate with an appropriate caregiver, while the disinhibited form is more enduring. ICD-10 states the disinhibited form "tends to persist despite marked changes in environmental circumstances". Disinhibited and inhibited are not opposites in terms of attachment disorder and can coexist in the same child. The question of whether there are two subtypes has been raised. The World Health Organization acknowledges that there is uncertainty regarding the diagnostic criteria and the appropriate subdivision.