IDD-MH Prescriber Guidelines

IDD-MH Prescriber Guidelines

Funded by the WITH Foundation

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Medical Assessment Considerations for Patients with IDD-MH: 

Common acute and chronic health conditions that impact people with IDD and their MH presentation

I. Leslie Rubin, MD & Lauren R. Charlot, PhD, LICSW


For the mental health provider who cares for the behavioral and mental health needs of people with intellectual and developmental disabilities (IDD), the challenges are manifold.

  • The person with IDD may have difficulty with language and be unable to describe their symptoms, making it difficult to explore a medical, emotional, social or environmental history, which are the cornerstones of a clinical diagnosis.
  • For the individual who is unable to articulate symptoms, the behavioral expressions of the symptoms may not bear any resemblance to the actual cause of the pain or discomfort. At times, with individuals who are on the autism spectrum, there may be dramatic emotional reactions out of proportion to the symptomatology, or, even in the presence of significant pain, there may be minimal symptomatology.
  • An individual with IDD is likely to be brought to the medical provider by a family member or a familiar supporter or, in some instances, they may be accompanied by an escort with limited or no prior experience with the individual.  If the third party is a family member or supporter, then interpretations of symptomatology and the provision of a reasonable history will help to make a diagnosis; however, if the third party is an unfamiliar escort, then the history is minimal or non-existent.
  • If a physical examination is necessary, the individual may be fearful and uncooperative, thus making it difficult to confirm clinical suspicions or explore physical conditions that may be causing the symptomatology.

With these provisos in mind, it behooves the prescriber to be aware of the limitations in making a diagnosis based on history and behavior. The important lesson is to keep an open mind and consider a differential diagnosis of disorders of behavior including mental health considerations, as well as possible medical conditions or environmental factors that can result in behavioral manifestations of pain or discomfort.

There are additional elements required in obtaining a good clinical history:

  • Examine and explore the individual’s patterns of behavior relating to daily health and routine. This includes eating habits, sleeping habits, bowel and bladder routines, exercise routines, work routines, social routines, as well as habits such as smoking or drinking alcohol or other emotional outlets. 
  • Inquire about any changes that may have taken place in any of the daily routines, as well as changes in the person’s weight. It is also strongly advisable to obtain a history of living circumstances, past and present, with attention to any changes that may have taken place in the recent past.
  • Review past medical history, which includes all past physical health related events, previous diagnoses, notes from specialty health care providers, as well as histories of allergies; past medications; medication responses and reactions; current medications, including the duration of the regimen, with exploration of possible drug interactions; previous emergency room visits; hospitalizations and past history of behavioral responses to medical, social and environmental experiences.

Answers to all these questions help to create a multidimensional picture of the individual and the complex interplay between physiological, social, emotional, and environmental factors. It also helps guide an assessment of the current clinical challenge to determine whether further evaluations or referrals are necessary, and assure a more accurate diagnosis, appropriate treatment and therapeutic recommendations, and favorable outcomes.

Etiological Considerations

Important to the clinical assessment of an individual with IDD is the etiology of the condition. Different etiologies that include prenatal, perinatal, and postnatal causes, as well as genotype and phenotype, will explain physical characteristics, behavioral patterns, and in some cases, organ system disorders. An etiological framework of developmental disabilities from neuromotor, neurocognitive and neurobehavioral perspectives can help the clinician conceptualize the underlying central nervous system disorder. Varied etiologies can determine the clinical manifestations and shape understanding, diagnosis and management.

Knowledge of the etiological diagnosis is an invaluable aspect in the clinical assessment of an individual with IDD. Three illustrative examples will be offered: individuals on the autism spectrum who tend to have less obvious physical or medical co-morbidities; individuals with predominantly motor disabilities such as cerebral palsy, who are likely to have more complex physical and medical co-morbidities; and individuals with an underlying congenital chromosomal or non-chromosomal syndrome, such as Down Syndrome, which each have their own unique physical characteristics, pattern of underlying organ system disorders, and at times, patterns of behavior. It is important to note that within each of these categories there are variations and variabilities as well as commonalities. In each, the level of cognitive ability and ability to communicate will vary greatly, and there may be overlapping diagnoses. So, an individual with Cerebral Palsy or Down Syndrome may also have Autism Spectrum Disorder. Similarly, the underlying central nervous system disorder often plays out with similar physical and mental health concerns as are experienced by the general population but with greater frequency and often to a greater degree. Thus, each person with IDD should be seen as unique, but with some likely physical and behavioral tendencies that will help to establish an accurate physical or mental health diagnosis.

Autism Spectrum Disorders (ASD)

Autism Spectrum Disorder (ASD) varies from person to person and the degree of difficulty varies, making it important for the prescriber to know the patient and their unique abilities. Individuals with ASD have underlying difficulties with communication, interaction and socialization, and can become easily frustrated in being unable to express themselves or make a request. This can lead to distress which may manifest in a fright, flight, or fight response with serious consequences. They are also more likely to have exaggerated reactions to sensory stimuli that may not bother anyone else. Their overreactions in these two examples may be misinterpreted in terms of behavioral pathology or a mental health disorder, so careful attention needs to be paid to the circumstances of any dramatic behavioral presentation.

Individuals with ASD are also more likely to have repetitive mannerisms and behaviors, tic disorders and even Tourette’s syndrome and seizure disorders. Therefore, unusual patterns of action or movement need to be analyzed to more accurately understand the nature and thus the approach to management. Individuals with ASD also have psychiatric comorbidities such as ADHD, anxiety, OCD, sleep disorders, Tourette Syndrome, depression, bipolar disorder, episodic dyscontrol syndrome, and psychoses. These need to be factored into the diagnostic consideration and managed accordingly.

Because individuals with ASD have limited communication skills, a tendency for unusual over- or under-sensitivity to sensory stimuli and emotional overreactions, physical symptoms may manifest in behavioral reactions. This is best documented with gastrointestinal disorders such as gastroesophageal reflux (GERD) and constipation. Because individuals with ASD and/or IDD may be unable to describe their symptoms accurately, discomfort or pain may be expressed with a variety of symptoms from withdrawal (especially with constipation), to frustration associated with emotional or behavioral challenges. Both medical conditions can be easily missed because the symptoms may be in the form of non-specific emotional or behavioral presentations with no clinically observable physical or medical signs or symptoms. The challenge to the clinician with these underlying medical conditions is that it may be difficult to get a complete or comprehensive history or even perform a thorough examination to determine the diagnosis, and even so, it may be difficult to diagnose clinically because there may be no obvious findings.

In these situations, it becomes imperative to develop an approach that is systematic in exploring changes in the environment and in reviewing the possible non-visible conditions that might explain physical pain or discomfort that may be present, such as a headache, dental pain, or abdominal pain. It is therefore critical to explore the possible physical conditions before attributing the behaviors to a psychological or psychiatric cause.

Cerebral Palsy (CP) 

Cerebral Palsy (CP) is defined as a disorder of movement and posture as a result of a fixed insult to the developing brain that occurred before, during or soon after birth. The severity of symptoms of CP occur across a spectrum and the diagnosis is based on the presence of motor characteristics with significant functional implications, but the reality is that the Central Nervous System (CNS) lesions are often diffuse and involve other functional elements. The CDC reports that for those with CP, more than 40% have intellectual disability, 35% have epilepsy, and more than 15% have vision impairment.1 The association of ASD and CP has been found in the US and other countries, as well.

Overall, the prevalence of behavioral and mental health disorders in CP is higher than the general population, especially as people age. When evaluating an individual with CP it is important to be aware of emotional and social factors in the person’s life as these may result in frustration, anger, anxiety or depression. Furthermore, care providers who are family members may also be stressed because of the physical demands of supporting a person with physical limitations in activities of daily living or because of other related stresses that may be emotional, social or even financial difficulty.

Individuals with CP are more likely to have complex medical problems. There is the obvious musculoskeletal involvement with limitations in movement and changes in posture, as well as muscle spasms or even at times tremors and clonus. They are more likely to have seizures, which may be expressed in a variety of different forms that can be confused with behavior disorders. Seizure medication is also more likely to be prescribed, which can cause a variety of different symptoms ranging from gastrointestinal disorders, metabolic and hematological disorders, and often changes in behavior. Seizure medications can also cause symptoms like headaches and dizziness that can manifest in behavior challenges (due to functional communication limitations). Individuals with CP are more likely to have other organ system disorders and ailments that may occur in the general population but in greater frequency and intensity, most notably disorders of the gastrointestinal tract such as GERD and constipation. 

The critical clinical element for the health care provider is to be aware of common conditions; to make specific inquiries of the patient, family members, and caregivers; and if there is an index of suspicion, refer the patient for an x-ray of the abdomen to rule out constipation, or to a gastroenterologist for further evaluation. It is quite acceptable, clinically, to prescribe laxatives if constipation is suspected and monitor the outcome, or to prescribe an antacid or anti-reflux mediation if GERD is suspected.   These ‘first aid’ measures will hopefully provide some relief to the patient with a reduction in symptoms with consequent improvement in presentation and assist the clinician in making a more accurate diagnosis

Diagnostic Syndromes

People who have a chromosomal anomaly (genotype) or a non-chromosomal syndrome are likely to have distinctive physical characteristics (physical phenotype), characteristic organ system involvement and often a behavioral phenotype. For reviews of a compendium of genotypes and phenotypes it is helpful to consult the latest edition of Smith's Recognizable Patterns of Human Malformation2, first published in 1969 and now in its 7th edition. This book offers a compilation of chromosomal and non-chromosomal disorders along with physical descriptions and associated organ system complications and medical comorbidities. In addition, the reader is referred to the text Health Care for People with Intellectual and Developmental Disabilities Across the Lifespan.3 Although this text is not as comprehensive and inclusive in cataloging the multiple known and unknown syndromes, it does contain in-depth information on a select group of relatively common conditions with more detail on the medical complications of each of the syndromes discussed. It has a comprehensive review of all physical and mental health considerations as well as familial, educational and social aspects of health and health care.   

Down syndrome is the most common and well-known of the genotypes associated with IDD. It has a variety of associated organ system conditions that may manifest at birth. Examples include congenital anomalies such as congenital heart lesions, and gastrointestinal anomalies such as duodenal stenosis or Hirschsprung’s. Although the congenital lesions are dramatic and require urgent care including surgery, it is the other conditions that people with Down syndrome are prone to that pose clinical challenges to the primary care provider as well as the mental health care provider.

In these situations, the clinician should become familiar with the range and variety of medical conditions. For one, visual and hearing impairments are common and may affect behavior at any age, so it is very important to be aware of these possibilities and refer for evaluation when suspected. Like other individuals with IDD, a person with Down syndrome may have GERD and constipation which need evaluation. In addition, hormonal disorders, most notably hypothyroidism, may manifest as loss of energy or lethargy. Regular screening for hypothyroidism is recommended. Musculoskeletal disorders are also more common in people with Down syndrome, including hypotonia with ligamentous laxity and tendency for dislocations and subluxations. Particularly worrisome is the tendency for atlanto-axial subluxation – involving cervical vertebrae C1 on C2, which may manifest in an inability to walk and is often misinterpreted as willfulness (or less strengths-based, as non-compliance). People with Down syndrome are more likely to have ADHD and ASD than the general population, so it is particularly important that the clinician is aware of these conditions and look beyond the Down syndrome diagnosis. Like everyone else, people with Down syndrome may have mental health conditions as well as adverse life experiences that shape their presentation. For the clinician taking care of people with Down syndrome it is important to be aware that they are more likely to develop Alzheimer’s dementia at an earlier age than the general population and that it may present with unusual behaviors. 

1 Center for Disease Control. Data and Statistics for Cerebral Palsy. Accessed:

2 Jones, KL, Jones, MC, Del Campo, M. Smith’s Recognizable Patterns of Human Malformation: Expert Consult 7th Edition. Elsevier, CA; 2020.

3 Rubin IL, Merrick J, Greydanus DE, Patel DR. Health Care for People with Intellectual and Developmental Disabilities Across the Lifespan. Dordrecht, NY: Springer; 2016:601-1606.

Medication Adverse Effects

A serious consideration for the clinician is that people with IDD may have additional neurological or medical conditions that require medication management, and that all medication may have side effects. Side effects can have metabolic, hematological or organ system effects, particularly if taken long term, and it is likely that there may be neuromotor, neurobehavioral or neuropsychiatric adverse effects. Medication should be thoroughly reviewed on a regular basis and, when assessing an individual for changes in behavior, it is important to determine the onset of the symptoms in relation to changes in medication administration.   In relation to medication administration, it is critically important to be sure that the individual is indeed taking the medication, that is, knowing that it is given and that it is swallowed. One last medication consideration is that there may be a difference in effect between different generic medications, which should be discussed with the pharmacy if suspected.


For any clinician who provides physical or mental health services for people with IDD, be it a primary care or specialty provider, it is important to be aware of the physical health conditions that may manifest as mental health or behavioral health disorders. This section provides an overview for the reader to become familiar with the common medical conditions that are often missed because people with IDD may not be able to describe their symptoms accurately or clinicians do not know how to elicit the needed responses.  There are many conditions that are not obvious on physical examination. The most common, the most serious and the most often missed, are the gastrointestinal disorders of GERD and constipation, but, as reviewed above, there are many other possible conditions that need to be considered.

The important messages for the clinician are to:

  • Conduct a broader-based examination than might be usual for patients without IDD. This means testing for common causes of irritability and aggression. Assistance with the clinical interview by someone who knows how to elicit accurate responses from the patient may be needed.
  • Be aware of the medical conditions that may present with behavior changes or challenges. Obtain laboratory tests where appropriate and consult with specialty providers if necessary.     
  • When possible, take a good history from the patients themselves, family members, and other healthcare providers – sometimes the more perspectives, the easier it is to make a diagnosis.  Review the medical, psychiatric, environmental and social histories.
  • Ask informants to describe what they saw and heard, rather than hypotheses. A timeline that begins from baseline wellness to changes in presentation (medication changes, altered eating, drinking, sleeping, weight, etc.) may be helpful to understand potential contributing factors.
  • Be aware that other practitioners may also have minimal historical information that can result in misdiagnosis.

Realize that there are common psychotropic side effects that can often be missed. People with IDD have atypical nervous systems and other anomalies and have been found to be at an elevated risk not only for health problems but also for adverse drug events.


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