Developmental disability is a diverse group of chronic conditions, comprising mental or physical impairments that arise before adulthood. Developmental disabilities cause individuals living with them many difficulties in certain areas of life, especially in "language, mobility, learning, self-help, and independent living".Center for Disease Control and Prevention. (2013). Developmental disabilities. Retrieved October 18, 2013 Developmental disabilities can be detected early on and persist throughout an individual's lifespan. Developmental disability that affects all areas of a child's development is sometimes referred to as global developmental delay.
Common developmental disabilities The most common developmental disabilities are: Motor disorders, and learning difficulties such as dyslexia, Tourette's syndrome, dyspraxia, dysgraphia, dyscalculia, and nonverbal learning disorder; individuals affected may still display high levels of individual accomplishment. Autism spectrum disorder (ASD, formerly the PDD umbrella covering Asperger syndrome and classic autism) causes difficulties in social communication as well as repetitive behaviors and restrictive interests. ASD affects speech, understanding body language and social interactions, as well as causing difficulty in understanding others' social cues (such as sarcasm and feelings). ASD also causes repetitive behaviors known as stimming, often as a result of hyper- or hypo-sensitivity to sensory input; individuals affected may still display high levels of individual accomplishment. Down syndrome is a genetic condition in which people are born with an extra copy of chromosome 21. This extra copy affects the development of the body and brain, causing a range of physical and mental impairments and disabilities for the individual. Fragile X syndrome, most frequent among males, is thought to cause autism and intellectual disability. Fetal alcohol spectrum disorders are a group of conditions caused prior to birth that can occur in a person whose mother drank alcohol during pregnancy. Cerebral palsy is a group of disorders that affect a person's ability to move and maintain balance and posture. They are the most common motor disability in childhood. Intellectual disability is defined as assessed to have an IQ below 70, along with limitations in adaptive functioning and onset before the age of 18 years.DSM-IV - Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision, American Psychiatric Association (APA, 1994) Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by executive dysfunction. It interferes with attention span, self-control, emotional regulation — key aspects of cognitive control; individuals affected may still display high levels of individual accomplishment.
Causes The causes of developmental disabilities are varied and remain unknown in a large proportion of cases. Even in cases of known etiology, the line between "cause" and "effect" is not always clear, leading to difficulty in categorizing causes.Improving health outcomes for children and youth with developmental disabilities, A literature review/Surrey Place Services, 2013
Genetic factors have long been implicated in causing developmental disabilities. These conditions are also believed to have a large environmental component, and the relative contributions of nature versus nurture have been debated for decades.Finucane, B.(2012) Introduction to special issue on developmental disabilities. National Society of Genetic Counselors, Inc. 749-751. Preterm birth is known to be a predictor for potential developmental disabilities later in childhood, which complicates the question of nature versus nurture, as
Current theories on causation focus on genetic factors; more than 1,000 known genetic conditions include developmental disabilities as a symptom.
Developmental disabilities affect between 1 and 2% of the population in most western countries, although many government sources acknowledge that statistics are flawed in this area. The worldwide proportion of people with developmental disabilities is believed to be approximately 1.4%. Such disabilities are twice as common in males as in females, and some researchers have found that the prevalence of mild developmental disabilities is likely to be higher in areas of poverty and deprivation, and among people of certain ethnicities.
Diagnosis and quantification Developmental disabilities can be initially suspected when a child does not reach expected child development stages. Subsequently, a differential diagnosis may be used to diagnose an underlying disease, which may include a physical examination and genetic tests.
The degree of disability can be quantified by assigning a developmental age to a person, who may be classified by age group resulting from their test scores. This, in turn, can be used to calculate a (DQ) as follows:, in turn citing Mosby's Medical Dictionary, 8th edition.
Associated issues
Physical health issues Many physical health factors associated with developmental disabilities. For some specific syndromes and diagnoses, these are inherent, such as poor heart function in people with Down syndrome. People with severe communication difficulties find it difficult to articulate their health needs and, without adequate support and education, might not recognize ill health. Epilepsy, sensory problems (such as poor vision and hearing), obesity, and poor dental health are over-represented in this population. Life expectancy among people with developmental disabilities as a group is estimated at 20 years below average, although this is improving. Society has advanced in its adaptive and medical technologies, and other methods to help people lead healthier, more fulfilling lives. In addition, some conditions (such as Freeman–Sheldon syndrome) do not affect life expectancy.
Mental health issues (dual diagnoses) Mental health issues, and psychiatric illnesses, are more likely to occur in people with developmental disabilities than in the general population, including amongst children who need the support of caregivers who have sufficient psychoeducation and peer support. A number of factors are attributed to the high incidence rate of dual diagnoses: The high likelihood of encountering traumatic events throughout their lifetime (such as abandonment by loved ones, abuse, bullying and harassment) The social and developmental restrictions placed upon people with developmental disabilities (such as lack of education, poverty, limited employment opportunities, limited opportunities for fulfilling relationships, boredom) Biological factors (such as brain injury, epilepsy, illicit and prescribed drug and alcohol misuse) Developmental factors (such as lack of understanding of social norms and appropriate behavior, inability of those around to allow/understand expressions of grief and other human emotions) External monitoring factor: all federal- or state-funded residences are required to have some form of behavioral monitoring for each person with developmental disability at the residence. With this information psychological diagnoses are more easily given than with the general population that has less consistent monitoring. Access to health care providers: in the United States, all federal- or state-funded residences require the residents to have annual visits to various health care providers. With consistent visits to health care providers more people with developmental disabilities are likely to receive appropriate treatment than the general population that is not required to visit various health care providers.
These problems are exacerbated by difficulties in diagnosis of mental health issues, and in appropriate treatment and medication, as for physical health issues.
Post-traumatic stress disorder Risks and development
Individuals with developmental disabilities have an increased risk of developing post-traumatic stress disorder compared to the general population due to heightened vulnerability to negative life experiences, including: Interpersonal trauma Abuse Dependence on caregivers Lack of autonomy Diminished social support Harassment Stigma and prejudice
Post-traumatic stress disorder is a psychological disorder that can develop after experiencing or witnessing trauma and is characterized by negative thoughts, memories, or dreams about the trauma, avoidance of reminders of the trauma, adverse changes in thinking and mood, and heightened acute stress response. Post-traumatic stress disorder often goes undiagnosed among individuals with developmental disabilities due to providers' and caregivers' lack of understanding and differences in communication ability.
Individuals with developmental disabilities may develop more intense symptoms of post-traumatic stress disorder when compared to the general population due to maladaptive coping and neurological differences. These symptoms may manifest differently depending on the severity of the disability; post-traumatic stress disorder may present as challenging behaviors such as aggression and self-harm, and communication of symptoms may be limited by verbal ability. Mental health problems are often reported by proxy rather than self-report, which can increase the risk of underreporting and of psychological symptoms going undiagnosed.
Psychological treatment
Diagnosis, assessment, and treatment approaches for post-traumatic stress disorder typically require verbal communication and insight into cognitions, emotions, and functioning. Individual differences in communication and intellectual ability among individuals with developmental, and particularly intellectual disabilities can limit identification and treatment of post-traumatic stress disorder symptoms. Thus, diagnosis and treatment approaches should be modified to fit the individual.
Some individuals with developmental disabilities may have difficulty understanding and articulating negative thought processes and emotions associated with traumatic events. Metaphors, simplified explanations, and explicit examples may help elucidate symptoms of post-traumatic stress disorder and improve understanding of treatment approaches. Frequent prompting, repetition of explanations, and developing detailed timelines of life events may also improve focus and engagement in psychological treatment. Providers should clearly understand individual needs and abilities and ensure that expectations for treatment are consistent with individual abilities and functioning.
The following trauma-specific treatments have demonstrated efficacy among individuals with developmental disabilities, particularly when tailored to individual needs and presentation.
Child–parent psychotherapy