Issues in assessing people with intellectual disability for anxiety

  People with intellectual disability may have difficulty recognising anxiety symptoms as symptoms of mental illness and may have lived with their fears and worries for many years. Anxiety symptoms may go undiagnosed or may be attributed to personality or intellectual disability. People with intellectual disability may find it difficult to recognise and describe symptoms of anxiety due to cognitive and language abilities. Examples are: • A person with mild intellectual disability who does not leave the house because of a fear of dogs may not recognise that those fears are excessive, especially if a dog had bitten them in the past, • A person with moderate intellectual disability and compulsive hand washing may not be able to identify the origins of those thoughts, and • Some people with intellectual disability do not have verbal skills and are unable to discuss symptoms at all. Anxiety symptoms in people with borderline or mild intellectual disability may be no different to those experienced by the general population. However anxiety disorders may present with different symptoms in people with moderate or severe  disability. Examples include: • Obsessions and compulsions may not be seen as repetitive and excessive by the person and there may be no attempt to resist them, • There may be no opportunity to avoid specific situations, places or people if the person has no say in where they go each day, • Behavioural symptoms such as irritability, aggression and restlessness are more common than in the general population, and are often attributed to the disability.   These issues are considered in the alternative classification system for people with an intellectual disability, the DC-LD, which was created to ensure that people with ID and anxiety disorder are not disadvantaged by criteria created for use in the general population.  DC-LD criteria for anxiety differ from general population criteria by, amongst other things, including objective evidence (such as observed or reported physical symptoms of anxiety – tremor, shaking, sweating etc.), excluding overly complex symptoms (such as depersonalisation and derealisation), and including the behavioural features of anxiety disorders. Comprehensive assessment is required, as physical disorders and other psychiatric disorders can present with anxiety symptoms Examples include: • Physical illness and disorders (e.g. hyperthyroidism, epilepsy) • Behavioural phenotypes can be associated with specific anxiety disorders (Prader-Willi Syndrome, Fragile X Syndrome) • Other psychiatric disorders may present with anxiety smptoms (adjustment disorders, psychotic illness) • Adverse effects of medication (particularly asthma medications, steroids, antidepressants, cold and flu preparations) • Substance use, intoxication and withdrawal (caffeine, nicotine alcohol, cannabis, cocaine and amphetamines)