The Forthcoming DSM-5, Critical Care Medicine, and Pediatric Neuropsychiatry: Which New Concepts Do We Need?

The brain frequently becomes a target organ of pathology in the context of critical illness, revealing secondary neuropsychiatric disorders. Disturbances in brain functioning may lead to autonomic nervous system failure, which is strongly associated with increased morbidity and mortality. Five common secondary neuropsychiatric disorders, or “Organic Reaction Types of the Brain,” are 1) sickness behavior, 2) fever, 3) epilepsy, 4) delirium, and 5) catatonia. Sickness behavior is defined as a dramatically changed behavioral repertoire, which occurs almost universally in humans and mammals after infectious diseases, cancer, and chemotherapy.^7,8 Its characteristics are attentional disturbances, anorexia, fatigue, emotional lability, loss of interest, and malaise. Sickness behavior explains the high prevalence of prodromal delirium in critical illness.⁹ Although a clearly-defined syndrome of clinical and scientific importance, its existence as a diagnostic category is neglected in both the DSM-IV-TR and the proposed DSM-5.¹⁰ One solution is to create a new subsection “Organic Reaction Types of the Brain,” with descriptive text and a set of diagnostic criteria in the chapter, titled “Mental Disorders Due to a General Medical Condition.”

An important issue regards the diagnosis of pediatric delirium in critically ill children <16 months, since, at the pediatric intensive care unit, 80% of children are <36 months, and 50% are <12 months. The DSM-IV-TR section on children does not mention pediatric delirium. Whereas diagnosis of delirium in adults relies heavily on neurocognitive symptoms, diagnosis of delirium in children relies more on behavioral symptoms, given the difficulty of assessing neurocognition in infants. The five Pediatric Anaesthesiology Emergence Delirium criteria: eye contact, awareness of surroundings and caregiver, purposeful actions, inconsolability, and restlessness may represent appropriate diagnostic criteria in DSM-5.¹¹ Another issue is that the DSM-IV-TR flow chart “Differential Diagnosis of Mental Disorders Due to a General Medical Condition” has two omissions.⁹ First, there is no consideration of the fact that nearly all pediatric intensive-care unit patients already have disturbances of consciousness and cognition—due to sickness behavior and analgo-sedation, and, thus, already have pre-delirium. Furthermore, for a flow chart to be of use in a (pediatric) intensive-care unit context, its starting-point should be the everyday occurrence of 1) “a sudden emotional and behavioral disturbance in a critically ill patient” and/or 2) “refractory agitation,” rather than the current entry cue of “symptoms that are due to the direct physiological effects of a general medical condition.” The flow chart should discuss in logical order of clinical importance the differential diagnoses of the underlying causes: major somatic complications, discomfort causes, psychosocial deprivation, delirium, and medication-related causes: withdrawal/tolerance/paradoxical excitation. Also, the sequential order of the current flow chart—although logical in itself—seems inadequate, as, in critical illness, several causes frequently operate simultaneously. Our proposed change for DSM-5 is to devote a section to “Emotional and Behavioral Issues in the Critically Ill (Child),” combined with a novel flow chart and pediatric delirium criteria.

Whereas much is known about organic reaction types of the brain in adults and elderly persons, considerably less expertise exists for children, especially regarding catatonia.¹² By conceptualizing catatonic symptoms as part of another disorder, the catatonic state remains underrecognized, particularly in the context of diagnosis and treatment of an underlying critical illness. It has become clear that catatonia deserves recognition as an important and treatable syndrome by itself, in adults and children alike.¹² The DSM-5 Development Proposed Revision section announces a new chapter titled “Catatonia,” which will present a descriptive text and diagnostic criteria. We agree, but are concerned that, up until now, no differential diagnostic criteria have been formulated that aid in making the distinctions among 1) hyperactive delirium; 2) autism; and 3) anti-NMDA–receptor encephalitis (see below). Additional paragraphs in the related chapters presenting these differential diagnostic criteria may be required.

DSM-IV-TR recognizes two pediatric pervasive developmental disorders, characterized by a normal development, followed by regression, often leading to severe cognitive decline: Rett’s Disorder and Childhood Disintegrative Disorder. In practice, a large number of children are diagnosed with the category: Pervasive Developmental Disorder, Not Otherwise Specified, including any form of atypical autism. The forthcoming DSM-5 subsumes all these disorders, under “Autism Spectrum Disorders.” Also, DSM-5 encourages clinicians to use a “specifier” in cases where known medical disorders play a role. Since 2007, a new Axis III diagnosis exists: anti-NMDA-receptor encephalitis. In children, its main Axis I differential diagnoses include Childhood Disintegrative Disorder, Early-Onset Schizophrenia, Late-Onset Autism, and Catatonia.¹³ Given the severe neuropsychiatric presentation and integrated psychiatric and somatic approach toward etiology, treatment, and outcome, this new (critical and potentially lethal) illness must not be missed. Therefore, regressive disorders in the context of possible somatic disorders must be given due attention, for example, by creating a section titled “Regressive Disorders in Infancy and Childhood,” and by adding a separate subsection titled “anti-NMDA-receptor encephalitis across all ages,” including diagnostic criteria in the chapter “Mental Disorders Due to a General Medical Condition.”

DSM-5 proposes that the current DSM-IV-TR chapter devoted specifically to children is omitted. Instead, there will be a chapter titled “Neurodevelopmental Disorders” including most of the childhood diagnostic conditions. In the other DSM-5 chapters, paragraphs presenting age-related symptoms and age-related subtypes will be included where applicable. We applaud these intentions of The Lifespan Developmental Approaches Study Group. However, given 1) the lack of an elementary chapter titled “Children,” and 2) the confusing name of the chapter “Neurodevelopmental Disorders,” we are not reassured. This approach may give rise to a diagnostic maze, especially for non-mental health colleagues working in child health.

By addressing the five issues described above, DSM-5 will incorporate new scientific and clinical insights, paying attention, in some instances for the first time, to common neuropsychiatric aspects and problems. Most of these issues have not been recognized, or not properly appreciated, until recently. By identifying, structuring, and discussing these in the DSM language, “conditio sine qua non” is met for the first time; clinical care for all the critically ill—as well as future scientific research—will be better equipped to blossom.

Authors’ contributions: Jan Schieveld first conceived the idea for this manuscript; he and Jim van Os wrote the first draft. All others participated in criticizing and re-writing the next drafts, and all authors agree with the final version of the manuscript.