Clinical practice guidelines for cognitive impairment in Autism spectrum disorder – Assessment and management

Authors: Satya Raj, Merlin Thanka Jemi, Priya Mammen

INTRODUCTION

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social communication, repetitive behaviors, and a restricted repertoire of interests and activities. It has its onset during early childhood, and the functional deficits often persist throughout the individual’s lifespan.[1] The estimated prevalence in India ranges between 0.74 and 1.68% per 100 in children aged 2–9 years, according to which 1 in every 68 children is affected with autism.[2]

The clinical presentation of ASD is very heterogeneous, attributed to differences in developmental trajectories, gender, language abilities, cognitive functioning, adaptive behaviors, and associated medical and psychiatric comorbidities.[3] In addition to the core deficits, individuals with ASD often face significant difficulties in the cognitive domain. Cognitive functioning varies across the spectrum, with some children having mild deficits, others (30–70%) having significant delays or intellectual disability,[4] and some with extraordinary abilities or ‘splinter skills’ in a specific domain.[5] Cognitive functioning is essential in determining the type of service, the level of support, and the educational placement required for the child.[6]

Individuals with ASD and comorbid intellectual disability (IQ < 70) are more likely to present early in the course of the disorder, given caregivers concern about the overt delays or cognitive impairments noted in the child. However, children with higher-functioning ASD (without comorbid intellectual disability or significant language delay) often have challenges due to less apparent impairments in cognitive functioning. While research into the cognitive impairments in individuals with higher-functioning ASD has many gaps in its evaluation and interventions, the scope of this guideline is to attempt to translate this into practice [Table 1].

Need for the guideline

Specific cognitive impairments are noted in individuals with ASD, and the manifestations of the same have a significant impact across the lifespan of the individual. Cognitive deficits in ASD can be noted in children, adolescents, and adults with average/low average or borderline intelligence. Therefore, cognitive functioning needs to be assessed for planning the necessary interventions. Cognitive assessment is required for academic guidance and support in children and adolescents and for vocational support in adults with ASD.

Challenges in assessment of individuals with ASD

Children with ASD can have comorbid developmental delay or intellectual disability which may overshadow the cognitive deficits in ASD. On the other hand, children with average development or intellectual functioning may also have cognitive deficits specific to ASD. In children and adolescents, the impairment could be at the sensory perception level or cognitive processing level or can affect learning and memory. Similarly, adults with ASD also present with social and nonsocial cognitive deficits causing significant social and occupational impairments. The major drawback in assessments of these cognitive deficits is that there are no specific diagnostic criteria for cognitive impairment in ASD, and moreover, the deficits identified are not specific to ASD.

Process of development of this guideline

Pubmed search was done using relevant terms, like “cognitive impairment”, “cognitive deficits”, and “assessments and interventions for specific cognitive deficits in ASD”. The specific guidelines for ASD, developmental delay assessments, and interventions were also reviewed, and the information was amalgamated in the current guidelines.

Scope of the guideline

The guideline will outline the cognitive deficits in individuals with ASD across the lifespan with predominant focus on children and adolescents and a brief note on adults with ASD.

Children with ASD can be broadly classified into two categories based on the developmental/cognitive

ASD with developmental delay/intellectual disability (DQ/IQ < 70)ASD with borderline/low average/average/above average development/intelligence (DQ/IQ > 70)

This guideline will focus on the second group of children. A brief note on the relevant developmental assessments and tests of intelligence will be made, highlighting the specific profiles noted in children with ASD. Specific screening measures and diagnostic assessments for development/intelligence will not be elaborated in this document. (Please refer to the Clinical Practice Guidelines for Assessment and Management of Intellectual Disability, Indian Journal of Psychiatry, 2019).[8]

Specific screening and diagnostic tools for ASD will not be elaborated in this document. (Please refer to the Clinical Practice Guidelines for Assessment and Management of ASD, Indian Journal of Psychiatry, 2019).[9]

COGNITIVE DEFICITS IN ASD

Cognitive functions are the primary mental processes involved in acquiring information, knowledge, and reasoning. The DSM 5 has defined six main domains of cognitive complex attention, memory and learning, executive function, perceptual-motor control, language, and social cognition. Individuals with ASD can have both delayed and atypical cognitive profiles, and even in those without associated intellectual disability, impairments in cognitive functioning have been documented.[1011]

Neurobiological theories of cognitive impairments in ASD

** *Executive function and frontal * ** Damasio and Maurer, in 1978,[12] put forward the executive dysfunction theory in ASD, postulating that individuals with ASD have deficits in executive functions similar to that seen in patients with frontal lobe damage. The frontal lobes, primarily the prefrontal cortex, have been associated with goal-oriented behaviors which require planning and execution of appropriate action plans. This appears to be a significant deficit in individuals with ASD as they struggle to complete a plan effectively and lack the flexibility needed to adapt to change.[13] ** *Social cognition and limbic-associated neural * ** While higher cortical structures play a significant role in cognitive intelligence, dysfunction in the ventromedial prefrontal cortex, amygdala, and limbic system associated with processing of emotions may explain social cognitive deficits seen in ASD.[14] ** Spatial reasoning, memory, and hippocampus ** The hippocampus has been implicated in impaired cognitive functions of spatial reasoning as well as episodic memory deficits in ASD. As the timeline of the development of the hippocampus and the emergence of the core symptoms of ASD coincide, studies have noted structural abnormalities and functional connectivity deficits. Episodic memory impairments in ASD have been attributed to both encoding and retrieval process deficits in the hippocampus, revealed through fMRI studies.[1516] ** Sensory processing ** Cognition can be affected at the cellular and genetic levels.[17] Visual, auditory, and tactile sensory perceptions are all integrated and need to function optimally for effective cognitive processing. Individuals with ASD are noted to have sensory perception abnormalities, leading to sensory integration difficulties. Problems in visual processing, which are often seen in ASD, have led to studies looking at retinal changes as early markers of cognitive impairments in these individuals. ** Systemic causes ** Neurological, immune, oxidative stress, and gastrointestinal dysfunction have been hypothesized to lead to cognitive impairments in ASD. Immune dysfunction is shown to cause neuroinflammation; this, in turn, affects the neural connectivity, glutamate/gamma-aminobutyric acid (GABA) balance, cognitive processing, memory, learning, and brain plasticity.[171819] Oxidative stress and dysfunctional mitochondria affect the myelination of neurons directly or indirectly. The activation of multiple cortical areas, adequate functional connectivity, and balance in GABA, glutamate, oxytocin, and vasopressin are required for adequate cognitive flexibility, which is often impaired in individuals with ASD.[20] However, while neuroinflammatory biomarkers have been identified in ASD, they are not specific to ASD and treatments targeting chronic inflammation have not been effective to date, requiring more clinical trials.

Cognitive processing in ASD

Various psychological theories have been proposed to explain cognitive processing differences in individuals with ASD.

** Central coherence dysfunction and local processing bias ** Central coherence is the ability to integrate information in context for higher-level meaning or gestalt. Individuals with ASD appear to show “weak” coherence, attending preferentially to details at the expense of the whole or gestalt. Weak coherence has been postulated to result in symptoms like insistence on sameness, rigidity in thinking, and uneven cognitive profiles seen in individuals with ASD. While both global and local processing is a requirement for normal sensory processing, atypical and preferential local processing with impairment in global processing in ASD can lead to difficulties in making sense of the world around and this in turn can affect social cognition.[2122] ** Theory of mind (ToM) deficits ** The ToM concept, otherwise known as ‘mind-blindness’ or ‘mentalization failure’, was described by Baron-Cohen in his study of children with ASD.[23] ToM is the ability to infer the mental states of others and understand that this can differ from one’s own belief. Individuals with ASD are known to have deficits in this process, often leading to difficulties in understanding social nuances. ** Joint attention difficulties ** Joint attention is the ability to coordinate attention between a social partner and an object or event, resulting in ongoing engagement with a communication partner and object.[24] There are two types of joint attention described, namely, supported and coordinated. Joint attention is a predictor of language and higher social skills as children grow. Individuals with ASD have delays in developing joint attention.

Cognitive impairments associated with ASD:

The cognitive impairments in ASD are broadly classified into nonsocial or neurocognitive impairments and social cognitive impairments [Figure 1].[25]

A. Neurocognition/nonsocial cognition

Executive functions are defined[26] as a flexible, strategic plan of action to solve a problem or attain a future goal. Deficits in executive functioning affect the routine day-to-day activities in individuals with ASD due to perseverative responses, rigidity in routines, repetitive behaviors, and decreased impulse control.

Executive functions can be divided into two

a)Higher-order executive function skills of organization, planning, working memory (WM), mental flexibility, response initiation, response inhibition, impulse control, self-regulation, and action monitoring.b)Lower-order skills like motor skills, short-term memory, and language.[27]

The primary lower-order skills are simple and develop by 2–4 years, while the higher-order skills are more complex and develop later by 4–7 years.[28]

The significant components of executive function, influencing multiple components of learning, are briefly mentioned below[29]

Organize/plan: The ability to plan, organize, and problem-solve effectively.Working memory: A type of short-term memory that stores information temporarily during the completion of a task and actively manipulates and transforms the information needed to complete the cognitive task. It comprises the central executive, visuo-spatial sketch pad and the phonological loop.Cognitive/mental flexibility: The ability to change thought and behavior, according to changes in the environment.Response initiation/fluency: The ability to generate verbal and nonverbal stimuli including ideas, designs, and words and spontaneously engage in purposeful goal-directed activities.Inhibition: The ability to deliberately inhibit automatic, dominant responses when required.Impulse control: A set of behaviors that help us think before actingSelf-monitoring: Regulating emotions and behavior to accommodate social situations.Shifting set: The ability to shift back and forth between multiple stimuli, operations, or mental sets.

B. Social cognition

Social cognition refers to the perception and interpretation of social information. Individuals with ASD have social and communication deficits, with trouble in understanding people’s goals, intentions, and emotional states.[29] Social cognition includes three main social perception, emotion recognition, and theory of mind.

Social perception: The ability to be aware of the cues and rules that occur in social situationsEmotional recognition: The ability to recognize the feelings of self and othersTheory of mind: The ability to attribute beliefs and intentions to oneself and others

Cognitive deficits in adults with ASD

Systematic review and meta-analysis have shown that adults also showed specific patterns of cognitive deficits in social and nonsocial cognition domains. The domains evaluated in the nonsocial cognition and social cognition which was used in schizophrenia have been adopted for the ASD population.[30]

Adults with ASD have shown to have deficits in nonsocial cognition, social cognition, and adaptive behavior functioning. It has been suggested that interventions to work on the cognitive deficits may help the adaptive skills as well.[31] A cross-sectional study showed that adults with ASD had reduced ToM abilities as compared to the neurotypical individuals of their age.[32]

ASSESSMENT OF COGNITIVE FUNCTION IN ASD

Assessment of cognitive functions in a child with ASD should be done by trained personnel only, following evaluation by a child psychiatrist, pediatric neurologist, or developmental pediatrician. This is important for confirming a diagnosis of ASD and ensuring that medical and psychiatric comorbid conditions have been addressed before assessment and treatment plans are formulated [Figure 2].

Note: In areas where specialist teams are not available, cognitive deficits can be assessed by psychiatrists/psychologists, and referral to higher centres can be done as needed or as required.

Before proceeding with assessments looking at specific cognitive impairments in children who are the target of this guideline, developmental/intellectual testing and adaptive functioning assessment using standardized tests will need to be done. This will help first to delineate those children with ASD without comorbid developmental/intellectual/language impairments and secondly plan further assessment based on the unique cognitive profile of the individual child.

Developmental/intellectual assessments need to be administered in individuals with ASD prior to assessment of the specific cognitive deficits in ASD. Adaptive functioning will also need to be evaluated along with developmental and intellectual assessments as discrepancy between the cognitive and adaptive functioning may be seen in individual with ASD. Similarly, in adults as well, assessment of the overall intellectual functioning and then the assessment of the specific cognitive deficits may help us understand the cognitive profile and the impairment present [Tables 2 and 3].

Disclaimer: Comprehensive assessment by trained personnel is required to understand the cognitive deficits of the individuals with ASD and aid in framing tailor-made interventions, as “no one size fits all”, in ASD due to heterogeneity and varied presentations.

Assessing developmental age in an uncooperative child with ASD:

Some children with ASD may not cooperate for a formal assessment of DQ or IQ; in such cases, the Psycho-educational Profile revised (PEP R) can used to assess the developmental age, and the interventions can be planned accordingly.[39]

Specific assessments for cognitive impairments in individuals in ASD without comorbid intellectual disability [Tables 4-8].

INTERVENTIONS FOR COGNITIVE DEFICITS IN ASD

Nonpharmacological interventions [Table 9]

Interventions for the cognitive impairments in ASD should be planned, targeting the specific nonsocial and social impairments that are seen in the individual. Many of these strategies have been extrapolated from interventions carried out in adults with brain damage or schizophrenia and tried in other disorders like ASD, ADHD, and learning disabilities. While some of these interventions are listed below, they are still relatively new in children and need to be further studied.

Cognitive Remediation Therapy (CRT) Cognitive remediation therapy (CRT) is a therapeutic approach which has been extensively studied in schizophrenia. It improves cognitive processes through individual behavioral training using repetitive exercises and positive reinforcement. CRT has been tried for the executive functioning deficits seen in adults and children with ASD, comprising of modules working on cognitive flexibility, working memory, and planning. A systematic review showed that cognitive remediation approaches in ASD individuals effectively addressed cognitive deficits of working memory and phoneme flexibility, suggesting growing evidence for cognitive training in improving executive functions in individuals with ASD.[5960] Cognitive flexibility training Cognitive flexibility is an ability that allows people to shift their attentional focus on complex tasks, and deficit in the same is seen in individuals with autism spectrum disorder. Cognitive flexibility training uses play and games to improve cognitive flexibility, planning ability, and use of language among children and adolescents with autism.[61] Cognitive Enhancement Therapy (CET) Research on the cognitive impairments in ASD and domain-specific interventions have shown that executive functioning impairments can, in turn, affect social cognitive functioning. The need to consider interventions that can be more integrative in cognitive rehabilitative approaches led to the development of therapies like CET, a multidimensional program integrating neurocognitive training targeting attention, memory, and problem-solving, as well as social cognitive training. Participants are initially paired for initial sessions in neurocognitive training with coach trainers. Small social-cognitive groups are then formed with structured sessions to work on socialization, problem-solving, and perspective-taking, with homework assignments to generalize skills to their daily life over 18 months. While the effectiveness of CET has been found in schizophrenia, its potential effectiveness with minor adaptations in adults with ASD has also been shown.[62]Cognitive training using video games[63]Smartphone-based games can be used to train working memory in children with ASD. The team developed five games, basket game, train game, piano game, face game, and shape game, and studied the effectiveness of the same in improving working memory. The games were open-source, free of cost to the community, and designed to match the children’s behavioral preferences and sensorimotor abilities. A preliminary 1-month intervention trial was conducted to test the effectiveness of the intervention. Though no statistically significant change was noted, children who performed better on the games appeared to improve in their working memory, suggesting that a longer game-based intervention might help improve working memory. Physical exercise Recent network meta-analysis has looked at the effect of different types of physical exercise on executive function in children with ASD. A medium effect size was seen in the domains of inhibitory control and cognitive flexibility with certain physical sports like mini-basketball, ping pong, exergaming, and martial arts, with differential effects in specific sports and overall more effects in inhibitory control. While there were some improvements in working memory, especially in games like ping pong, the effect size was lower than in the other two domains. The analysis suggests that certain physical sports can be recommended to improve executive functioning in individuals with ASD.[64] Social Skills Training (SST) SST refers to a wide range of group-based interventions and instructional methods commonly used to help understand and improve social skills. It focuses on developing effective communication skills, enhancing social interaction skills, improving the ability to initiate and maintain conversations, enhancing perspective-taking (ToM) and empathy skills, building self-awareness and self-regulation skills, and promoting emotional understanding and emotional control. SST programs can vary according to the child’s chronological age and skill level. Social skills for younger children with autism address fundamental play skills like eye contact and turn-taking. In adolescents and young adults, the focus shifts to expressing opinions, initiating and maintaining conversations, and maintaining friendships and workplace behavior. Standard techniques used in social skills training are peer-mediated interventions and instructions, modeling and role-playing, social narratives, visual supports, video modeling, and cognitive behavior therapy.[65]

Social skills group training for children and adolescents with ASD has shown to have modest and inconsistent effects according to a randomized control trial done by Olson. School-based social skills training has also been shown to have minimal evidence in children with ASD.[6667]

Recently, there has been an increasing focus on the use of “behavioural intervention technologies” in social skills training. (BITs - SST).[68]

Some examples of SST programs

Social Cognition and Interaction Training (SCIT): SCIT is used in adolescents to improve social attention, social cognition, and social skills.Education and Enrichment of Relational Skills (PEERS): PEERS is a group-based program developed at UCLA for children with ASD. The program involves 90-minute weekly sessions targeting social skills for 3–4 months. The children are taught these skills through role-play, group activities, and parent involvement to ensure the skills are practiced at home and in the community. This intervention has shown to be beneficial even after the training sessions are over.Assistive Soft Skills and Employment Training (ASSET): ASSET is an intervention focusing on work-related social skills. This can be used in adults to work on their vocational skills.

The therapeutic strategies suggested needs to be tailormade for the individual with ASD. It can be advised by trained personnel, psychiatrists/psychologists and can be implemented by the care givers at home but would need ongoing supervision and periodic re-evaluation to assess the trajectory of the progress and problems or challenges if any.

Pharmacological interventions

Specific evidence-based pharmacological management is recommended for ASD in the presence of severe levels of stereotypies, self-injurious behavior, hyperactivity, and sleep dysregulation or to manage other comorbid medical or psychiatric disorders. While the potential benefit of nonpharmacological interventions to address cognitive deficits in individuals with ASD is noted, the evidence for pharmacotherapy in this specific area is limited [Table 10].

As seen in the table given, current evidence for pharmacological management specifically for cognitive impairments in ASD is weak and therefore is not recommended.

CONCLUSION

In summary, ASD, being a very heterogeneous condition, can present with varying levels of cognitive functioning, ranging from average/above average intelligence to individuals with intellectual disability. However, even among individuals with ASD in the absence of comorbid intellectual disability, cognitive profiles can differ from the norm, with specific impairments in social and nonsocial cognitive domains. As these impairments can impair day-to-day functioning, it is essential to evaluate them to tailor interventions to suit the individual needs. Research addressing specific assessments and interventions addressing these cognitive impairments in individuals with ASD is still relatively new and ongoing. The neuropsychological concepts and assessments for cognitive impairments in ASD without an intellectual disability have been highlighted in this guideline, along with suggestions for interventions.

Conflicts of interest

There are no conflicts of interest.