The most substantive clinical advance in Developmental Neuropsychiatry  during the last year is the publication of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) . DSM-5 replaces the DSMIV section ‘Disorders usually first diagnosed in infancy, childhood, or adolescence’ with a new section, Neurodevelopmental Disorders. The new DSM-5 classification includes two new categories of brain dysfunction: neurodevelopmental disorders with onset in the developmental period and major neurocognitive disorders (e.g. Alzheimer's Disease) with onset in later life [2,3]. Moreover, a developmental focus is sustained throughout the DSM-5 Manual for each disorder described. A major change in DSM-5 is the elimination of the multiaxial classification system utilized in previous DSM manuals. The multiaxial system has proved useful for disorders beginning in the development period for treatment planning and in discussing the patient's prognosis with others.
The DSM-5 alternative to the multiaxial classification is to emphasize the approach to clinical case formation and to provide specifiers for neurodevelopmental disorders. The updated section in DSM-5 on Use of this Manual explains that case formulation is essential ‘to assist trained clinicians in the diagnosis of their patients’ mental disorder’ by making clear that ‘it is not sufficient to simply check off the symptoms in the diagnostic criteria to make a mental disorder diagnosis’ (2, p. 19). The clinical case formulation is a clinical summary of the social, psychological and biological factors that contribute to the development of a mental disorder. Thus, the clinical formulation requirement in DSM-5 is more extensive than was the multiaxial system. It clarifies that a mental disorder must be viewed in the context of case formulation for treatment planning. DSM-5 includes specifiers that allow more homogeneous subgroupings of a disorder to indicate shared features. Thus, the diagnostician can, for several of the neurodevelopmental disorders [e.g. autism spectrum disorder (ASD) and intellectual disability/intellectual developmental disorder (ID/IDD)], specify association with a known genetic condition and designate that genetic condition by name. Moreover, DSM-5 defines clinical significance of a disorder. Clinical significance requires consideration of thresholds of a person's distress or impairment in his or her social, occupational and/or other important areas of functioning in daily life.
The Neurodevelopmental Disorders section replaces the outmoded term mental retardation with intellectual disability (intellectual developmental disorder) and defines levels of severity based on adaptive functioning and not IQ scores [3,4]. Communication disorders are newly named. This category encompasses language disorder (replacing expressive and mixed receptive-expressive language disorders), speech sound disorder (replacing phonological disorder), childhood-onset fluency disorder (replacing stuttering), and social (pragmatic) communication disorder, a newly introduced category that defines difficulties in the social uses of verbal and nonverbal communication. Specific learning disorder is a new category that combines reading disorder, mathematics disorder, disorder of written expression and learning disorder not otherwise specified. Deficits in reading, written expression and mathematics are coded separately in DSM-5 as specifiers. The DSM-5 text recognizes that types of reading deficits are sometimes described internationally as dyslexia and specific types of mathematics deficits as dyscalculia. Motor disorders are now organized as developmental coordination disorder, stereotypical movement disorder, Tourette's disorder, persistent (chronic) motor or vocal tic disorder, and other specified and unspecified tic disorder. Tic criteria are standardized throughout this section. The DSM-5 text description for stereotypical movement disorder has been extensively rewritten to reflect the importance of this category in the diagnosis of self-injurious behavior, a major problem in the management of people with severe and profound specifiers of intellectual disability (intellectual developmental disorder). When making this diagnosis, the clinician is required to specify with or without self-injurious behavior and to specify any associated medical or genetic condition, neurodevelopmental disorder (e.g. intellectual disability/intellectual developmental disorder) or associated environmental factor, for example intrauterine alcohol exposure.
Attention-deficit hyperactivity disorder (ADHD) is newly placed in the Neurodevelopmental Disorders section in DSM-5, whereas it was classified with disruptive behavior disorders in DSMIV. Disruptive behaviors now include disruptive, impulse control and conduct disorders. There are several changes to the diagnostic criteria for ADHD. Examples have been added to criterion items to make it easier to classify the disorder across the lifespan. The age of onset has been changed to onset prior to age 12 years. Specifiers are added to designate combined, predominately inattentive, and predominately hyperactive/impulsive presentations. In DSM-5, ADHD and ASD can be diagnosed as co-occuring in the same person. The threshold to indicate clinical impairment for affected adults has changed. The criterion for an ADHD diagnosis for adults is five symptoms instead of the six required for younger people both for inattention and for hyperactive/impulsive presentations.
The biggest change in the Neurodevelopmental Disorders section in DSM-5 is the creation of a new category, Autism Spectrum Disorder, along with the elimination of the DSMIV diagnostic category Pervasive Developmental Disorder and its subgroupings (autistic disorder, Asperger's disorder, childhood disintegrative disorder, Rett's disorder and pervasive developmental disorder not otherwise specified).
ASD is characterized by deficits in two core domains instead of three as in DSMIV. These are deficits in social communication and social interaction, and restricted repetitive patterns of behavior, interests and activities. The ASD criteria underwent field testing and were found to be reliable. A new category in the Communications Disorders section is Social (Pragmatic) Communication Disorder, which is intended to provide a means to code children with verbal and nonverbal deficits who do not meet ASD criteria for restricted repetitive patterns of behavior, interests and activities, and to allow more focus on developing specific treatment programs to meet their needs.
This issue of the journal includes four articles that discuss advances in selected DSM-5 diagnoses. One of these discusses fetal alcohol spectrum disorder, a condition that was considered for DSM-5 but not included in the main classification. A variant of fetal alcohol spectrum disorder, Neurobehavioral disorder associated with prenatal alcohol exposure (2, pp. 798–801), is included in Section III: Emerging Measures and Models under Conditions for Further Study in DSM-5. This section includes conditions in which additional research is needed before deciding about inclusion. Koren (pp. 98–104)  reviews progress toward a neurodevelopmental screening test for fetal alcohol spectrum disorder and its applicability in developing new interventions, including pilot-targeted school classes, that may affect long-term outcome. It is unfortunate that the proposed DSM-5 criteria for the alcohol-related neurobehavioral disorder listed is limited only to people with an ID/IDD diagnosis. Greater attention is needed to the identification of affected people with a diagnosis of fetal alcohol spectrum disorder whose IQ is in the low normal range because this is the group seen most commonly by psychiatrists and referred to the courts. Research on the effects of intrauterine exposure to alcohol is needed to further clarify criteria for fetal alcohol spectrum disorder.
King et al. (pp. 105–109)  in their Update on Diagnostic Classification in Autism review the scrutiny that the diagnostic construct of autism underwent, leading to the decision in DSM-5 to replace pervasive developmental disorder with autism spectrum disorder. They review the history of the autism diagnosis from its introduction by Kanner [7,8] to the DSM-5. They point out that field studies conducted to date have found that the new DSM-5 criteria are inclusive and that the boundaries around the diagnosis have not been substantially altered. They explain the rationale of consolidating the three core symptoms into two and the inclusion of sensory hypo-sensitivity or hyper-sensitivity as a criterion. They remind the reader that diagnostic criteria may be met ‘by history.’ Importantly, they examine the controversy surrounding the elimination of the Asperger's subtype and reference pertinent scientific literature in support of this change. They report that genetic studies to date suggest that risks conferred are to autism spectrum disorders and not to a specific subtype. These authors discuss the importance of including specifiers of ASD. Others suggest that designating additional specifiers besides those included in DSM-5 may contribute to the identification of ASD subtypes in the future . Neuroimaging studies may contribute to identifying subtypes. For example, in approximately 25–30% of cases, there is substantial regression in cognitive functioning and behavior with loss of speech and social skills that typically occurs between 15 and 30 months, leading to a regressive subtype being proposed [10,11].
Rapid trajectory of head growth is one of the best documented findings in autism and occurs in a 25–30% of cases [10,11]. Recent neuroimaging findings suggest a correlation between regression in cognition and behavior and rapid trajectory of brain growth in affected preschool boys . With ongoing research, it is expected that new means will be found to identify subtypes of ASD for a future classification.
Greenspan and Woods (pp. 110–116)  in their article Intellectual disability as a disorder of reasoning and judgement: the gradual move away from intelligence quotient-ceilings emphasize the importance of the neurobiologically based, brain-based disorder perspective in DSM-5, rather than a disability focus. They explain that the use of full-scale IQ and IQ cut-off points to define severity is outmoded and highlight the critical importance of moving away from IQ ceilings and embracing an approach based on adaptive reasoning and judgment as described in DSM-5. They view the DSM-5 definition of ID/IDD as a transitional one that does not go far enough in addressing the issues they raise in their critique of the DSM-5 definition. Hauser et al. (pp. 117–121) , Psychiatric Disorders in People with Intellectual Disability (IDD): Forensic Aspects, emphasize the importance of the new ID/IDD definition in forensic settings. They emphasize the importance of the move away from IQ thresholds in forensic settings, where the full-scale IQ test score number has been misused in determining eligibility for the death penalty. These authors report that the frequency of contact with the legal system by people with ID/IDD diagnoses requires understanding of the unique features of this population.
Conflicts of interest
There are no conflicts of interest.
1. Harris JC. Assessment, diagnosis and treatment of the developmental disorders. New York:Oxford University Press; 1998.
2. American Psychiatric AssociationDiagnostic and statistical manual of mental disorders, 5th ed.Arlington, VA:American Psychiatric Association; 2013.
3. Harris JC. New terminology for mental retardation in DSM-5 and ICD-11. Curr Opin Psychiatry 2013; 26:260–262.
4. Salvador-Carulla L, Reed GM, Vaez-Azizi LM, et al. Intellectual developmental disorders: towards a new name, definition and framework for ‘mental retardation/intellectual disability’ in ICD-11. World Psychiatry 2011; 10:175–180.
5. Koren G, Zelner I, Nash K, Koren G. Foetal alcohol spectrum disorder: identifying the neurobehavioural phenotype and effective interventions. Curr Opin Psychiatry 2014; 27:98–104.
6. King BH, Navot N, Bernier R, Webb SJ. Update on diagnostic classification in autism. Curr Opin Psychiatry 2014; 27:105–109.
7. Kanner L. Autistic disturbances of affective contact. Nervous Child 1943; 2:217–250.
8. Kanner L. Follow-up study of eleven autistic children originally reported in 1943. J Autism Child Schizophr 1971; 1:119–145.
9. Lai MC, Lombardo MV, Chakrabarti B, Baron-Cohen S. Subgrouping the autism ‘spectrum’: reflections on DSM-5. PLoS Biol 2013; 11:e1001544.
10. Stefanatos GA. Regression in autistic spectrum disorders. Neuropsychol Rev 2008; 18:305–319.
11. Bigler ED, Abildskov TJ, PetrieAbildskov JA, et al. Volumetric and voxel-based morphometry findings in autism subjects with and without macrocephaly. Dev Neuropsychol 2010; 35:278–295.
12. Nordahl CW, Lange N, Li DD, et al. Brain enlargement is associated with regression in preschool-age boys with autism spectrum disorders. Proc Natl Acad Sci U S A 2011; 108:20195–20200.
13. Greenspan S, Woods GW. Intellectual disability as a disorder of reasoning and judgement: the gradual move away from intelligence quotient-ceilings. Curr Opin Psychiatry 2014; 27:110–116.
14. Hauser MJ, Olson E, Drogin EY. Psychiatric disorders in people with intellectual disability (intellectual developmental disorder): forensic aspects. Curr Opin Psychiatry 2014; 27:117–121.