IDD-MH Prescriber Guidelines

Psychiatric Assessment Considerations

L. Jarrett Barnhill, MD, DFAPA, FAACAP, Lauren R. Charlot, PhD, LICSW, and Dan Baker, PhD

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Epidemiological studies of people with Intellectual and Developmental Disabilities (IDD) suggest that a conservative estimate of the lifetime prevalence of behavioral and mental disorders is 30-40%.1 The accuracy of these data remains questionable due to the frequency of under-diagnosis and misdiagnosis of underlying medical/neurological disorders as mental health conditions. In addition, level of ID and adaptive functioning impacts the process of assessment, especially when related ecological, psychosocial factors increase vulnerability to stressors. The level of ID also affects communication of and capacity for self-reporting symptoms, and likelihood of diagnostic overshadowing. For example, pain and discomfort may present as externalizing, disruptive behaviors that can be misattributed to a psychiatric condition.

Each of these factors contributes to misdiagnoses and sets a chain of events in motion that culminates in ineffective psychological and psychopharmacological interventions. The task of the assessment team is to minimize these shortcomings. The most successful way to accomplish this involves integrating a comprehensive description of the presenting biopsychosocial issues; medical, familial, psychosocial, and treatment histories; and systematic genetic, medical/laboratory, psychological, and mental status examinations with observational data from the patient, family, and multiple care providers. Such an approach reinforces the reality that psychiatric disorders do not arise in a vacuum. Behavioral and psychiatric disorders represent evolving conditions that are profoundly influenced by ongoing transactions between biology and the environmental/social context. A comprehensive assessment requires a holistic-transactional mindset in order to look beyond simply treating an illness. It takes into account resilience and positive psychological forces to promote wellness and maximize adaptive skills.

1 Fletcher RJ, Barnhill J, Cooper S-A (Eds). Diagnostic Manual-Intellectual Disability 2: A Textbook of Diagnosis of Mental Disorders in Persons with Intellectual Disability. Kingston, NY: NADD Press; 2017.


Initial Psychiatric Assessment

The goal of initial psychiatric assessment for a patient with IDD is to gain an understanding of the biopsychosocial vulnerabilities of the person, their symptoms and potential treatment options. Methods of assessment for someone with IDD varies slightly from the general population.

General Population

Patients with IDD

Establish relationship with person

Relationship with the person and a team

Conversation, detailed questions & answers

Verbal ability may be limited; interview informants to gather additional information; use plain language to engage the patient in discussion

Evaluate overall presentation

Atypical presentation is likely, recognize behavioral phenotypes related to genetic syndromes, ASD, ID, etc.

Discuss diagnosis and treatment plan directly with the person

Along with consensus with the patient, a "team" treatment negotiation also occurs


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Sam is 34 years old and is diagnosed with Down Syndrome, moderate ID, and major depressive disorder. Sam also engaged in some level of self-injury since he was young, often expressing anxiety, worry, sadness or frustration by biting his hand, hitting his head, or other forms of self-harm. This month, his family noted an increase in self-injury compared to last month (40 incidents compared to an average of 5 per month for the previous 6 months). They also reported that the intensity of the incidents increased. Sam broke the skin on his hand from frequently biting it and they were concerned the wound might get infected. After an intense increase in self-injury during the month, coupled with lethargy to the point where Sam was unable to get out of bed, his parents took him to the emergency department for evaluation. He was sedated for the exam and the ER staff noticed a tumor in his abdomen causing kidney malfunction and pain.

Discussion: Situations of baseline exaggeration like Sam’s are too uncommon for individuals with IDD. This situation is an important reminder that a person’s increase in "behavior" needs to be recognized and addressed in the context of historical patterns of symptoms and cannot simply be evaluated as an event happening at one single point in time. If diagnostic overshadowing occurred and the ER physicians assumed that Sam was depressed, the underlying issue driving the exaggeration of symptoms would not be treated. Prescribers must remember that when a change in presentation occurs, there is usually a history to it. Understanding the potential reason for change increases success and efficacy of the treatment approach.

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WW: The many faces of Bipolar Disorder

WW is an 18-year-old male with mild Cerebral Palsy, Mild ID, and a long history of episodic hyperactivity, irritability, and aggression. His first contact with mental health services was at age five. His original diagnoses were ADHD, Oppositional Defiant Disorder, and Intermittent Explosive Disorder. He initially improved but had to discontinue both methylphenidate and dextro-amphetamine derivatives due to irritability and appetite loss. His PCP prescribed Risperidone 5 mg/d. His parents noted a significant reduction in irritability, but also noticed weight gain and increased motor activity (akathisia). The family tapered and discontinued risperidone. He seemed to return to his pleasant easy-going temperament. His family enrolled him in a developmental preschool program where he received physical therapy.

At age 8, WW presented with an episode of irritability, verbal outbursts, property destruction, and disruption. His working diagnosis was Intermittent Explosive Disorder despite persistent sadness, loss of appetite, and lethargy. His third-grade teacher voiced concerns about depression. His developmental pediatrician concurred and prescribed low dose fluoxetine (5 mg/d). The treatment plan called for a slow titration based on clinical response. WW improved initially but developed significant behavioral disinhibition on 20 mg/d. His outbursts returned and his prescriber tapered fluoxetine. Off fluoxetine, WW seemed to stabilize once again and thrived at school. 

At age 12, WW’s mother ended her life and the family was devastated. WW found his mother following her suicide and developed acute stress-related symptoms including nightmares, school avoidance, and multiple fears. These symptoms improved with therapy but his mood and level of interest in preferred activities (school and fishing) diminished. His developmental pediatrician attributed the mood changes to grief and trauma. Once again, his irritability and aggression intensified, and WW also developed panic attacks. His father sought out a local therapist who focused on trauma-related issues. WW improved over the next 3-6 months and therapy ended.

At age 18, WW developed an acute onset psychosis. He appeared delusional (he was an angel sent by his mother to save the world), hallucinations (voices commenting on his need to kill himself), and had disorganized thoughts, extreme hyperactivity, and marked increase in aggression. This resulted in his first psychiatric hospitalization. The treatment team agreed to initiate a rapid titration of an antipsychotic (Abilify) along with a medical and psychiatric workup. As his psychotic symptoms diminished, the team agreed that WW’s symptoms seemed more consistent with mania (reduced need for sleep, pressured speech, hyperactivity and impulsivity).

During the hospitalization, his father noted that his mother had severe bipolar disorder and psychotic postpartum depression after WW’s birth. Without her husband’s knowledge some years later, she discontinued her lithium and stopped her psychiatric care. Her mood soon crashed after the discontinuation. She ended her life three days before WW’s 12th birthday. With this new information, the inpatient team began a trial of lithium and as WW improved, they also began an Abilify taper. This was the first time that bipolar disorder was considered as a diagnosis for WW.



Components of Comprehensive Psychiatric Assessment for Patients with IDD

Several developmental, biological and psychosocial factors might influence altered mental status. These should be considered as part of regular assessment for patients with IDD.

Medical Concerns

As many as 40%1 of individuals with IDD referred for an inpatient psychiatric stay have a missed or under-treated medical problem that was the actual reason for challenging behaviors that led to the admission.

Syndromes associated with IDD

Several syndromes, primarily genetically-mediated, may give rise to an IDD and contribute to patterns of executive function deficits, increased risk for certain medical comorbidities, and even elevated risk for psychiatric symptoms and syndromes.

Psychosocial and systemic vulnerabilities

Vulnerabilities include challenges related to cognitive factors, information processing, and including executive functions; communication (especially functional and social-emotional communication); sensory sensitivities; restricted and repetitive behaviors; trauma histories; and residential and programmatic services. As suggested, such vulnerabilities may provoke problems or impact their expression.

Cognition/ Level of Intellectual Disability

It can be helpful to know a person’s level of intellectual disability (mild, moderate, severe, profound), however there is extreme variability within these characterizations in how people process information, problem solve, and plan. These differences influence what is experienced as stressful, the degree of stress experienced, and how a person responds.

Executive function (EF)

The term executive function is used to describe a set of cognitive functions that control and regulate other abilities and behavior. This includes planning, organizing, focusing and paying attention and problem solving. Patients with IDD tend to benefit from support with initiating activities, paying attention, finishing tasks, tolerating frustration and regulating emotions, all of which impact the ways the person navigates everyday life.   


People with IDD present with a very wide range of abilities and challenges with regard to communication. It is critical to help caregivers understand that speaking is not the same as problem solving and planning. Many people with IDD learn “scripts” but may not have insight into the meaning. 

Sensory sensitivities

Sensory sensitivities may occur in conjunction with a tendency to be easily over-aroused. Sensitivities to sounds is most common. Sensitivities to space (being too close), light touch, clothing tags on the skin, and overly stimulating visual environments are other examples.   

Repetitive behaviors

Perseveration and repetitive tendencies are common concerns for many with IDD. In some cases, especially with ASD, there seems to be a deep need for things to remain the same, and increased stress when there is change. Repetition can be a way to understand something better, to resist change, which is upsetting, and at times to experience enjoyment (when the repetition has a self-stimulatory aspect). If a repetitive behavior is aimed at stress or anxiety reduction, a replacement must be provided if it is to be eliminated.


Don’t Forget the Power of Psychotherapy

There are many factors that contribute to the way a person feels or behaves. Most factors are not deterministic but are among a series of interactions through many life experiences. Psychopharmacologists should not assume that a psychotropic drug can teach someone social and adaptive skills, problem-solving, or methods for self-care. Psychotropic drugs can reduce behavioral excesses due to exaggerated brain-behavioral responses that frequently stand in the way of psychosocial well-being. Remember, it takes an interdisciplinary treatment village to promote wellness. Psychotherapy is a much more powerful tool for enhancing wellness, emotional well-being, and mastery while enhancing life skills. In the Appendix is a list of evidence-based, frequently used therapeutic modalities and resources for physicians regarding the efficacy of the modalities for persons with IDD. 


Assessment is the most important part of any treatment program. It provides a comprehensive picture of a person’s symptoms in a biopsychosocial context and work towards holistic solutions to adverse life experiences. Psychopharmacological assessments are frequently reductionistic and limit consideration of the psychosocial and ecological forces that influence the emergence and course of psychiatric disorders.  All too often, the efficacy of medication is overestimated; psychotropics are adjuncts, not solutions. While medication may be a piece to the wellness puzzle, it is not the only one. Medications offer an intervention designed to alter the underlying biology of behavior, but they do not take the place of primary care, educators, therapists, friends or family members. The goals of assessment are to identify and develop strategies to enhance adaptive skills, with psychopharmacologic treatment playing one role in the process.

Considerations for Psychotherapeutic Adaptations

The following are considerations for adapting psychotherapy and other intervention methods during treatment involving persons with IDD:

  • Speed: Adaptations are often needed to provide intervention at a slower pace, allowing additional time to process the content and respond. This adaptation is commonly used in accommodations for academic testing when learners are given additional time during exams.
  • Number: Either more or fewer examples might be appropriate for a patient depending on the learning abilities and profiles they have. If the patient requires additional practice for acquiring a skill or concept, the adaptation would be to increase the number of exemplars used. If the patient has difficulty generating responses, fewer responses could be required.
  • Abstraction:  Adaptation based on abstractness involves reducing the level of abstraction and improving concreteness of content. This is accomplished by using objects, drawings, and role play rather than lecture, discussion, or reading materials. 
  • Complexity: These adaptations generally involve breaking content down into smaller chunks or units. This is familiar to special educators in the instructional technique of “task analysis.” Plain language is used to improve comprehension.

Resources by Therapeutic Approach:

There are many evidence-based practices that have been successfully adapted to improve health and wellness for persons with IDD. While the list below is not all-inclusive, it provides options for treating mental health conditions for persons with IDD.

Positive Psychology

  • Shogren KA, Wehmeyer ML, & Singh NN, eds. Handbook of Positive Psychology in Intellectual and Developmental Disabilities: Translating Research into Practice. New York, NY: Springer Publishing; 2017.
  • Niemiec RM, Shogren KA, & Wehmeyer ML. Character strengths and intellectual and developmental disability: A strengths-based approach from positive psychology. Ed Training Autism Dev Disabil. 2017; 52(1):13-25.

Positive Identity Development

  • Harvey K. Positive Identity Development: An Alternative Treatment Approach for Individuals with Mild and Moderate Intellectual Disabilities. Adv Ment Health and Intellect Disabil. 2011;5(6):57-58.
  • Baker DJ, Blumberg R. Mental Health and Wellness Supports in Youth with IDD. Kinston, NY: National Association for the Dually Diagnosed. 2013.

Trauma-Informed Care

  • Hales T, Kusmaul N, & Nochajski T. Exploring the Dimensionality of Trauma-Informed Care: Implications for Theory and Practice. Hum Serv Organ Manag Leadersh & Gov. 2017; 41(3):317-325.
  • Keesler J. A call for the integration of trauma-informed care among intellectual and developmental disability organizations. J Policy Pract Intellect Disabil. 2014;11(1):34-42.
  • Peterson C, Seligman ME. Character Strengths and Virtues: A Handbook and Classification. New York, NY: Oxford University Press; 2004;1.

Interactive Behavioral Therapy

  • Razza NJ, & Tomasulo DJ. Healing Trauma: The Power of Group Treatment for People with Intellectual Disabilities. Washington, DC: American Psychological Association; 2015.
  • Tomasulo DJ. Positive group psychotherapy modified for adults with intellectual disabilities.  J Ment Health Res Intellect Disabil. 2014;18(4):337-350.

Cognitive Behavioral Therapy

  • Harley SL, Esbensen AJ, Shaley R, Vincent LB, Mihaila MI, et al. Cognitive behavioral therapy for depressed adults with mild intellectual disability: A pilot study. J Ment Health Res Intellect Disabil. 2015;8(2):72-97.
  • Jahoda A. Cognitive-behavioural intervention for people with intellectual disability and anxiety disorders. J Appl Res Intellect Disabil. 2006;19 (1):91-97.

Positive-Cognitive Behavioral Therapy

  • Mira A, Breton-Lopez J, Enrique A, Castilla D, et al. Exploring the incorporation of a positive psychology component in cognitive behavioral internet-based program for depression symptoms. Results throughout the intervention process. Front Psychol. 2018; 9:2360.

Trauma-Focused Cognitive Behavioral Therapy

  • Ramirez de Arellano M, Lyman R, Jobe-Shields L, George P, Dougherty RH, et al. Trauma-focused cognitive behavioral therapy: assessing the evidence. Psychiat Serv. 2014; 65(5):591-602.

Dialectical Behavioral Therapy

  • Brown JF, Brown MZ, & Dibiasio P. Treating individuals with intellectual disabilities and challenging behaviors with adapted dialectical behavior therapy. J Ment Health Res Intellect Disabil. 2013; 6(4):280–303.

Acceptance and Commitment Therapy

  • Brown FJ, & Hooper S. Acceptance and commitment therapy (ACT) with a learning-disabled young person experiencing anxious and obsessive thoughts. J Intellect Disabil. 2009; 13(3):195-201.

Motivational Interviewing

  • Frielink N, & Embregts P. Modification of motivational interviewing for use with people with mild intellectual disability and challenging behavior. J Intellect Dev Disabil. 2013; 38(4): 279-291.

Exposure Therapy

  • Symons FJ. An evaluation of multi-component exposure treatment of needle phobia in an adult with autism and intellectual disability. J Appl Res Intellect Disabil. 2012; 26(4): 344-348.
  • Boyd BA, Woodard CR, & Bodfish JW. Feasibility of exposure response prevention to treat repetitive behaviors of children with autism and an intellectual disability: A brief report. Autism. 2011; 17(2).

Expressive Therapies

  • Gortner E, Rude SS, Pennebaker JW. Benefits of expressive writing in lowering rumination and depressive symptoms. Behav Ther. 20-6; 37(3): 292-303.
  • Thompson GA, Skewes-McFerran K. Music therapy with young people who have profound intellectual and developmental disability: Four case studies exploring communication and engagement within musical interactions. J Intellect Dev Dis. 2015; 40(1):1-11.
  • Miller SM. Disability art: Potential intersections in studio practice with artists labeled/with intellectual and developmental disabilities. Art Ther. 2020; 37(2): 93-96.
  • Tomasulo D, Szucs A. The ACTing cure: Evidence-based group treatment for people with intellectual disabilities. Dramatherapy. 2015; 37(2-3).


  • Anderson LL, Humphries K, McDermott S, & Marks B. The state of the science of health and wellness for adults with intellectual and developmental disabilities. Intellec Dev Disabil. 2013; 51(5): 385-398.
  • Young H, Erickson ML, Johnson KB, Johnson M, & McKully, K. A wellness program for individuals with disabilities: Using a student wellness coach approach. Disabil Health. 2015; 345-352.

Solution Focused Interventions

  • Roeden JM, Bannink FP, & Curfs LM. Solution-focused brief therapy with people with mild intellectual disabilities: A case series. J Policy Pract Intellect Disabil. 2011; 8(4): 247-255
  • Stoddart KP, McDonnell J, Temple V, & Mustata A. Is brief better? A modified brief solution-focused therapy approach for adults with a developmental delay. J Systemic Therap. 2001; 20(2): 24-40.

Eye Movement and Desensitization Re-processing (EMDR)

  • Gilderthorp J. Is EMDR an effective treatment for people diagnosed with both intellectual disability and post-traumatic stress disorder? J Intellect Disabil. 2015; 9(1): 58-68.


  • Yucha CB, & Montgomery D. Evidence-Based Practice in Biofeedback and Neurofeedback. Nevada: Association for Applied Psychophysiology and Biofeedback; 2008.

Occupational Therapy

  • Francisco I, & Carlson G. Occupational therapy and people with intellectual disability from culturally diverse backgrounds. Aust Occup Therap. 2002; 49(4):200-211.

Recreation Therapy

  • Merrells J, Buchanan A, & Waters R. The experience of social inclusion for people with intellectual disability within community recreational programs: A systematic review. J Intellect Dev Disabil. 2018; 43(4):381-391.
  • Garcia-Villamisar D, Dattilo J, & Muela C. Effects of therapeutic reaction on adults with ASD and ID: A preliminary randomized control trial. J Intellect Disabil Res. 2016; 61(4): 325-340.


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