One reason why dyslexia manifests itself differently from one individual to the next is that many students with dyslexia can be affected by co-existing or comorbid challenges. Some students with dyslexia also have Attention-Deficit Hyperactivity Disorder (ADHD), dysgraphia, dyscalculia, speech/language disorders, executive functioning disorder, and/or anxiety. A description of the most common conditions to accompany dyslexia are described in the text that follows.

Anxiety
Anxiety is a frequent emotional symptom demonstrated by students with dyslexia.  For some students, even when in the most supportive school/home environments, frustration, confusion, and anticipation of failure due to their own learning disability often impacts their ability to be successful. Schools and families can work together to provide systematic supports and interventions to enable students to learn to cope with anxiety. Learn more in the section entitled, “Social Emotional Impacts of Dyslexia.”

Attention-Deficit Hyperactivity Disorder (ADHD)
Dyslexia and ADHD are two distinct conditions that are often comorbid, however, one does not cause the other. A student who is diagnosed with ADHD can present with characteristics such as inattention, distractibility, hyperactivity, and impulsivity. According to the International Dyslexia Association (IDA), it is estimated that 30% of those with dyslexia have ADHD as well, making it one of the most common co-existing conditions with dyslexia. Upon completion of an evaluation, a physician or psychologist can diagnose the presence of ADHD in a student.

Dyscalculia
Dyscalculia is a mathematical disability in which a person has unexpected difficulty solving arithmetic problems and grasping math concepts, such as time, measurement, and spatial reasoning, as defined by the International Dyslexia Association (IDA). Like dyslexia, dyscalculia can occur in people at all levels of cognitive ability.

Many of the characteristics of dyscalculia are similar to the characteristics of dyslexia. If a student has problems with working memory, he or she is likely to have trouble memorizing math facts or completing multi-step calculations.

Dysgraphia
The IDA defines dysgraphia as the condition of impaired letter writing by hand, that is, disabled handwriting. This disability can interfere with learning to spell words in writing and the speed of composing and writing text. This condition may occur alone or in the presence of dyslexia. 

For instructional purposes, it is important for the teacher to be able to distinguish whether difficulties lie in handwriting only, spelling only, word reading and spelling only (dyslexia), or a combination of handwriting, spelling, and word reading. Students with dysgraphia may benefit from explicit handwriting instruction and early intervention. Keyboarding accommodations can often help these students to compose text more readily.

Executive Functioning Disorder
Executive functioning is the use of skills to organize and act on information. The executive functions are a diverse, but related and overlapping, set of skills that help people manage and control all life tasks.

The following are components of executive functioning

1. Metacognition, or the awareness of one’s own thought processes
2. Working memory
3. Attention and focus
4. Self-control
5. Goal-directed persistence
6. Cognitive Flexibility/Shift   

Students who have challenges in executive functioning may have difficulty paying attention, remembering details and maintaining control in order to analyze, plan, and organize information to complete tasks. Students may struggle with self-regulation, time management, self-motivation, and metacognitive skills to help with their learning and thinking processes. Executive functioning issues are often present in students diagnosed with ADHD and or dyslexia; however, students who struggle with reading and writing, can also present with these characteristics due to other mitigating factors such as frustration, discouragement, fear of failure, or lack of motivation.

Speech/Language Disorders
Students with dyslexia may also present with common speech/language disorders involving problems in the articulation of sounds and the accuracy of sound production and/or atypical oral language development. Although impairments in language and reading are distinct disorders, they are often closely related conditions. Speech and language are often evaluated as part of a comprehensive evaluation for dyslexia. Speech/language services are accessed through an Individualized Education Program (IEP), for students who qualify. Speech and language disorders can be a stand-alone category of eligibility for special education services as well as a co-existing condition.

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