https://cobe.paginas.ufsc.br/files/2014/10/GRADE-guidelines-32.pdf

GRADE guidelines: 3. Rating the quality of evidence

This article reviews the results of 43 studies published since 1966 that provided estimates for the prevalence of pervasive developmental disorders (PDDs), including autistic disorder, Asperger disorder, PDD not otherwise specified, and childhood disintegrative disorder. The prevalence of autistic disorder has increased in recent surveys and current estimates of prevalence are around 20/10,000, whereas the prevalence for PDD not otherwise specified is around 30/10,000 in recent surveys. Prevalence of Asperger disorder is much lower than that for autistic disorder and childhood disintegrative disorder is a very rare disorder with a prevalence of about 2/100,000. Combined all together, recent studies that have examined the whole spectrum of PDDs have consistently provided estimates in the 60-70/10,000 range, making PDD one of the most frequent childhood neurodevelopmental disorders. The meaning of the increase in prevalence in recent decades is reviewed. There is evidence that the broadening of the concept, the expansion of diagnostic criteria, the development of services, and improved awareness of the condition have played a major role in explaining this increase, although it cannot be ruled out that other factors might have also contributed to that trend.

/pdf/epidemiology-of-pervasive-developmental-disorders-2axz3hf754.pdf

Epidemiology of pervasive developmental disorders.

This paper was commissioned by the committee on the Effectiveness of Early Education in Autism of the National Research Council (NRC). It provides a review of epidemiological studies of pervasive developmental disorders (PDD) which updates a previously published article (The epidemiology of autism: a review. Psychological Medicine 1999; 29: 769–786). The design, sample characteristics of 32 surveys published between 1966 and 2001 are described. Recent surveys suggest that the rate for all forms of PDDs are around 30/10,000 but more recent surveys suggest that the estimate might be as high as 60/10,000. The rate for Asperger disorder is not well established, and a conservative figure is 2.5/10,000. Childhood disintegrative disorder is extremely rare with a pooled estimate across studies of 0.2/10,000. A detailed discussion of the possible interpretations of trends over time in prevalence rates is provided. There is evidence that changes in case definition and improved awareness explain much of the upward trend of rates in recent decades. However, available epidemiological surveys do not provide an adequate test of the hypothesis of a changing incidence of PDDs.

/pdf/epidemiological-surveys-of-autism-and-other-pervasive-3pfkr1vvb4.pdf

Epidemiological surveys of autism and other pervasive developmental disorders: an update.

We review research evidence on the emergence and development of active "self-and-other" awareness in infancy, and examine the importance of its motives and emotions to mental health practice with children. This relates to how communication begins and develops in infancy, how it influences the individual subject's movement, perception, and learning, and how the infant's biologically grounded self-regulation of internal state and self-conscious purposefulness is sustained through active engagement with sympathetic others. Mutual self-other-consciousness is found to play the lead role in developing a child's cooperative intelligence for cultural learning and language. A variety of preconceptions have animated rival research traditions investigating infant communication and cognition. We distinguish the concept of "intersubjectivity", and outline the history of its use in developmental research. The transforming body and brain of a human individual grows in active engagement with an environment of human factors--organic at first, then psychological or inter-mental. Adaptive, human-responsive processes are generated first by interneuronal activity within the developing brain as formation of the human embryo is regulated in a support-system of maternal tissues. Neural structures are further elaborated with the benefit of intra-uterine stimuli in the foetus, then supported in the rapidly growing forebrain and cerebellum of the young child by experience of the intuitive responses of parents and other human companions. We focus particularly on intrinsic patterns and processes in pre-natal and post-natal brain maturation that anticipate psychosocial support in infancy. The operation of an intrinsic motive formation (IMF) that developed in the core of the brain before birth is evident in the tightly integrated intermodal sensory-motor coordination of a newborn infant's orienting to stimuli and preferential learning of human signals, by the temporal coherence and intrinsic rhythms of infant behaviour, especially in communication, and neonates' extraordinary capacities for reactive and evocative imitation. The correct functioning of this integrated neural motivating system is found to be essential to the development of both the infant's purposeful consciousness and his or her ability to cooperate with other persons' actions and interests, and to learn from them. The relevance of infants' inherent intersubjectivity to major child mental health issues is highlighted by examining selected areas of clinical concern. We review recent findings on postnatal depression, prematurity, autism, ADHD, specific language impairments, and central auditory processing deficits, and comment on the efficacy of interventions that aim to support intrinsic motives for intersubjective communication when these are not developing normally.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/3DC59499840534E5455EEDB895666BF6/S0021963001006552a.pdf/div-class-title-infant-intersubjectivity-research-theory-and-clinical-applications-div.pdf

Infant intersubjectivity: research, theory, and clinical applications.

GRADE guidelines: 9. Rating up the quality of evidence

http://www.morrisonlucas.com/GL/vaccines/Lancet_353_2026_autism_and_measles_no_evidence.pdf

CPaddy Farrington

Papers

Autism and measles, mumps, and rubella vaccine: no epidemiological evidence for a causal association