Affiliated with Centura Health and Littleton Adventist Hospital

Call us: (720) 242-7533


Resources: Understanding Your Diagnosis

At Horizon Neuropsychological Services, we understand that it can be an emotional experience for someone to receive a diagnosis. For some, it is liberating to finally be able to put words to what they have been observing, while for others, it may bring about feelings of sadness or uncertainty. Regardless of your place in this process, understanding your diagnosis is the first step in moving forward and helping you to become the best version of yourself in life.

It is our hope that you can use our website as a starting place in researching your diagnosis. By clicking the drop-down button next to each diagnosis, you will find a brief summary of the diagnostic criteria, links to resources, and a list of recommended readings or podcasts. If you do not see your diagnosis below, please contact our office so we can provide you with the appropriate resources and reading materials.

Neurodevelopmental Disorders

Attention Deficit/Hyperactvity Disorder

Attention-Deficit/Hyperactivity Disorder (ADHD) is diagnosed when there are persistent issues with attention/focus that cannot be accounted for by another psychological and/or medical condition. Oftentimes, executive functioning challenges are also exhibited, such as difficulty with organizing, planning, and time management. Although not always present, some individuals also show fidgety behaviors, hyperactivity, and/or impulsivity.

Read more about Attention-Deficit/Hyperactivity Disorder:

It is important to note that many adults exhibit the above symptoms occasionally. In those with ADHD, however, symptoms are noticeably greater than others and cause distress and/or problems at home, at school/work, and/or with friends. Given the wide range of symptoms, an individual with ADHD will fall into one of three diagnostic categories: Predominantly Inattentive, Predominantly Hyperactive, or Combined Presentation.

Please visit the following sites for more information regarding Attention-Deficit/Hyperactivity Disorder:

Book Recommendations:

ADHD for college students

Smart but Scattered--and Stalled: 10 Steps to Help Young Adults Use Their Executive Skills to Set Goals, Make a Plan, and Successfully Leave the Nest by Richard Guare, Colin Guare, and Peg Dawson.

On Your Own: A College Readiness Guide for Teens With ADHD/LD by Patricia Quinn and Theresa Maitland.

Autism Spectrum Disorder

Autism Spectrum Disorder is a developmental disorder that affects communication and behavior across school, work, and/or other areas of life. Although professionals can diagnose Autism Spectrum Disorder at any age, symptoms generally start to appear in early childhood.

Read more about Autism Spectrum Disorder:

Please visit the following sites for more information regarding Autism Spectrum Disorder:

Video: Autism: One Man's Journey

Research has shown that Autism Spectrum Disorder presents differently in females than males. Please visit the following sites for more information regarding the way Autism Spectrum Disorder presents in women:

Book Recommendations:

Asperger’s and Adulthood: A Guide to Working, Loving, and Living With Asperger’s Syndrome by Blythe Grossberg

I am AspienWoman: The Unique Characteristics, Traits, and Gifts of Adult Females on the Autism Spectrum by Tania Marshall

Adults with Autism: A Guide to Diagnosis, Inner-Acceptance and Prosperity by Una Cuthbert and Claire Nicholls

Women and Girls with Autism Spectrum Disorder: Understanding Life Experiences from Early Childhood to Old Age by Sarah Hendrickx, Judith Gould, et al.

Autism in Heels: The Untold Story of a Female Life on the Spectrum by Jennifer Cook O'Toole, Jennifer O'Toole, et al.

Autism & the Transition to Adulthood: Success Beyond the Classroom by Paul Wehman, Marcia Smith, and Carol Schall

The Journal of Best Practices: A Memoir of Marriage, Asperger Syndrome, and One Man’s Quest to Be a Better Husband by David Finch.

Mild or Major Neurocognitive Disorders

Neurocognitive Disorders (NCD) are a set of diagnoses used to describe a change in cognitive functioning that is above what would be expected for normal aging and that is not better accounted for by a psychiatric disorder and/or delirium. NCDs are categorized as either Mild or Major, depending on factors such as performance on neuropsychological testing and how much the changes in cognitive functioning are interfering with a person’s ability to live independently.

Read More About Mild and Major Neurocognitive Disorders:

Mild Neurocognitive Disorder is also termed mild cognitive impairment (MCI). Individuals with mild NCD may experience a change in cognitive abilities, though they are still generally able to complete all their daily activities independently. However, greater effort is often required to complete these tasks than in the past. A diagnosis of mild NCD can only be made if the changes in cognition cannot be better explained by another psychiatric disorder and/or delirium.

While a diagnosis of mild NCD is certainly a risk factor for progressing to major NCD, many individuals with mild NCD never progress and some individuals even get better with time. The rate of progression of mild NCD is based on multiple factors, which can be discussed with your neuropsychologist and your other care providers (e.g., neurologist, primary care provider, etc.). However, neuropsychological testing is helpful in terms of better understanding current cognitive strengths and weaknesses, and for establishing a baseline against which to compare should there be any changes in the future.

Book Recommendations:

Keep Your Wits About You: The Science of Brain Maintenance as You Age by Dr. Vonetta Dotson, Ph.D.

The SharpBrains Guide to Brain Fitness: How to Optimize Brain Health and Performance at Any Age 2nd Edition by Alvaro Fernandez and Dr. Elkhonon Goldberg, Ph.D with Dr. Pascale Michelon, Ph.D.

Major Neurocognitive Disorder is defined as a significant decline from a prior level of cognitive functioning that is well above what would be expected in normal aging. The cognitive deficits seen in major NCD interfere with the individual’s ability to complete activities of daily living (e.g., managing medications, appointments, and finances, as well as cooking, shopping, navigating, and driving), often necessitating intervention from family members or medical providers. In more severe cases, individuals also often require assistance in basic activities of daily living, including bathing, toileting, eating, dressing, and grooming.

As with mild NCD, changes in cognitive functioning cannot be better explained by a psychological disorder and/or delirium. In many cases, major NCDs are due to a neurodegenerative or progressive disease process. In these cases, the term major NCD is used synonymously with dementia. The rate of progression of major NCD is, again, based on multiple factors, which can be discussed with your neuropsychologist and your other care providers. The presumed cause of major NCD is also determined by numerous factors, such as the neuropsychological profile (e.g., test results from a neuropsychological assessment), history (e.g., medical, psychological, educational, occupational), the rate of symptom onset/changes over time (i.e., progression), family history/genetic risk factors, and different lifestyle factors, among many others.

It should be noted that determining the specific cause for neurodegenerative changes in different types of dementia presentations can be somewhat nuanced. However, there are patterns of cognitive, motor, and mood/behavioral changes identified during a neuropsychological assessment that are most likely to represent one pathological process versus another. Additionally, results from neuroimaging, laboratory tests (e.g., bloodwork, spinal tap), and EEG, among others, can help to determine the appropriate diagnosis. The appropriate diagnostic tests to use are generally determined by the neurologist overseeing the patient’s care.

Neurocognitive Disorders can be due to (per the DSM-5):

            • Alzheimer’s Disease
            • Frontotemporal Lobar Degeneration
            • Lewy Body Disease
            • Vascular Disease
            • Traumatic Brain Injury
            • HIV Infection
            • Prion Disease
            • Parkinson’s Disease
            • Huntington’s Disease
            • Substance/medication use
            • Another medical condition
            • Multiple Etiologies
            • Unspecified

Additional information about each of these diagnoses is provided in the drop-down sections below.

Alzheimer’s Disease

Alzheimer’s disease is the most common cause for major NCD or dementia in older adults. It is a progressive, or “neurodegenerative” disease, that is characterized by the abnormal accumulation of proteins (amyloid plaques and tau tangles) in the brain, resulting in progressively worsening changes in cognitive functioning over time. The accumulation of these proteins tends to result in a specific pattern of changes in terms of cognitive functioning, including notable deficits in memory, semantic processing (e.g., trouble finding the right words to say), and more difficulty with tasks such as planning, organizing, problem-solving, and understanding complex concepts (among many others).

Please visit the following sites for more information regarding NCDs related to Alzheimer’s disease:

Frontotemporal Lobar Degeneration (FTLD)

Frontotemporal lobar degeneration (FTLD) refers to a group of neurodegenerative processes that primarily impact the frontal and temporal lobes of the brain. These areas of the brain are associated with behavioral control (e.g., socially appropriate behaviors), decision-making, emotional regulation, and language. There can also be motor changes (e.g., weakness or slowing of movement) seen in these disorders. FTLDs are one of the most common causes of dementia in adults aged 45-60. The clinical syndrome associated with FTLD is termed frontotemporal dementia (FTD). There are different variants of FTD based on the clinical presentation of the patient and the neurological systems most impacted, with the most common being:

      1. Behavioral variant frontotemporal dementia (bvFTD): This variant can severely impact personality and behavior, with many individuals exhibiting gradually increasing symptoms such as trouble controlling their behavior (e.g., impulse control, socially inappropriate behaviors) and/or increased apathy (e.g., decreased concern for others or understanding of the impact of their actions on those around them). There can also be gradual changes in language (finding/using the correct words, understating single words) and motor movements (e.g., weakness, slowed movements). This variant can severely impact multiple aspects of life, including family systems and work performance, as approximately 60% of the individuals diagnosed with this variant are between ages 45 and 64 (per the National Institutes of Health, 2019). For more information on bvFTD, the reader is directed to:
      1. Primary progressive aphasia (PPA): This is the second most common form of FTLD, and primarily impacts language abilities. Two common forms of PPA include:
        • Semantic Variant PPA: Individuals exhibit more trouble with understanding the meaning of different words or with pulling up the word they would like to use. Over time, individuals may use more general terms, such as “fruit” for “strawberry.”
        • Nonfluent/Agrammatic Variant PPA: In this form of PPA, individuals may have increased trouble with expressive language (i.e., getting words out). Their speech pattern may change, and sound more labored, halting, or slurred. Other symptoms include difficulty putting sentences together, utilizing grammatical rules, understanding grammatically complex sentences, or saying the correct word.

For additional information about the above and to learn more about other variants of PPA, please see:

Please visit the following sites for more information regarding FTLD:


Lewy Body Disease

Lewy body disease, or dementia with Lewy bodies (DLB), is another common form of dementia in older adults and is characterized by the abnormal accumulation of protein deposits, termed Lewy bodies, in the brain. These deposits can result in a progressive decline in cognition as well as changes in motor functioning, mood, and sleep behaviors. Additionally, individuals commonly experience symptoms such as visual hallucinations. Lewy Body Dementia and Parkinson’s disease (PD) share many common motor symptoms, including rigid muscles, tremors, slowed movements, and changes in gait/walking. Determining whether symptoms are more consistent with DLB versus PD can often be difficult given the significant overlap between symptoms.

Please visit the following sites for more information regarding NCDs related to Lewy Body disease:

Vascular Disease

Neurocognitive disorders can also be caused by underlying vascular disease. This can be related to a prior stroke, for example, though not all strokes result in vascular dementia. Other types of vascular changes that can impact brain health include medical conditions such as chronic hypertension, hyperlipidemia, heart disease, and diabetes. Each of these risk factors increase the likelihood for developing vascular dementia. While vascular dementia is often seen as a “stepwise progression” with cognitive changes that level out and remain stable for a time and then decline again, this is not always the case. Vascular disease can often be seen on neuroimaging, such as an MRI, though the extent to which vascular changes on neuroimaging are predictive of cognitive decline or the rate of disease progression is not well-understood.

Please visit the following sites for more information regarding NCDs related to Vascular disease:

Traumatic Brain Injury

A traumatic brain injury (TBI) is caused by sudden trauma to the brain following a hit to the head or from a penetrating head injury (i.e., object piercing through the skull and into the brain tissue). TBIs are often graded on a spectrum, ranging from mild, moderate, or severe, depending on multiple injury characteristics. These often include the length of loss of consciousness, presence of alteration of consciousness (i.e., change in cognitive status), presence of posttraumatic amnesia (i.e., whether there are any gaps in memory either before or after the injury), medical status examination (Glasgow Coma Scale), and whether there are any abnormalities found on neuroimaging (e.g., MRI and/or CT). Cognitive changes following a TBI also range greatly depending on the severity and extent of the injury, as well as numerous pre-injury factors that range based on the individual. For more detailed information on TBI severity criteria, the reader is directed to:

Mild: A mild TBI (mTBI) may result in immediate symptoms following the injury, which can include (but are not limited to) headaches, confusion, lightheadedness, dizziness, ringing in the ears, sensitivity to light and noise, fatigue, sleep changes, mood changes, and/or difficulty with different aspects of cognitive functioning (e.g., attention, memory, processing speed). The normal course of recovery for these symptoms is generally within hours and up to 3 months following injury. The recovery timeline varies by each individual. In a smaller subset of patients, these symptoms can persist for a longer period. While there is not currently a consensus about the etiology of these persisting symptoms, it is clear that they present significant problems in terms of daily functioning at work/school/home and a notable reduction in overall quality of life. Individuals with persisting symptoms following concussion are encouraged to speak with their neuropsychologist and/or their other healthcare providers about interventions that may be helpful for addressing these symptoms.

Moderate to Severe TBI: Individuals who have suffered a moderate or severe TBI exhibit many of the same symptoms as those with mTBI, but at a greater intensity and for a longer duration. Individuals who sustain a severe TBI often require extended hospitalization following the injury to stabilize their symptoms. More severe symptoms, such as seizures, can also occur and require ongoing management from a medical doctor (most often from a neurologist). Behavioral and mood changes are common, including increased agitation and combativeness and decreased inhibition (e.g., difficulty with socially appropriate behaviors). Cognitive changes vary greatly based on the extent and location of the injury, as well as multiple other factors including (but not limited to) premorbid history, biopsychosocial considerations, and medical history. Neuropsychological assessment is often recommended to determine cognitive strengths and weaknesses, which help to inform treatment programs.

Please visit the following sites for more information regarding NCDs related to Traumatic Brain Injury:

Book Recommendations:

The Brain Injury Workbook: Exercises for Cognitive Rehabilitation 2nd Edition by Trevor Powell


Substance/Medication-induced NCDs can result when cognitive symptoms persist after the resolution of acute intoxication and withdrawal symptoms (if applicable) from medication and/or another substance. If there are deficits in cognitive abilities, these would represent a change or decline from prior to use of the substance/medication and may impact the ability to complete daily tasks (e.g., depending on the level of severity of the neurocognitive disorder). Some individuals may experience mild improvements in cognition following sustained abstinence from the substance, though it is difficult to predict the extent of these improvements in cognitive functioning for each individual.

Please visit the following sites for more information regarding Substance/Medication-Induced NCDs:

HIV Infection

Individuals living with HIV can develop a spectrum of symptoms over time, including cognitive, psychological, and motor changes, that cause difficulties with daily tasks. These symptoms have been termed HIV-Associated Neurocognitive Disorder (HAND) and can range from mild to severe in terms of the level to which this constellation of symptoms interferes with daily life. HAND is not typically thought to be a progressive disorder, and these symptoms are generally relatively mild for individuals who are on anti-retroviral therapy (ART).

Please visit the following sites for more information regarding NCDs related to HIV Infection:

Prion Disease

These types of diseases are rare but rapidly progressive and represent a serious medical condition when they are identified. They are associated with an infectious agent or “prion” that infect host proteins, resulting in a fatal infection in the brain. The most common prion disease in humans is called Creutzfeldt-Jakob disease (CJD). The course of CJD is generally quite rapid, with progression from onset to end-of-life usually being within one year. Both inherited and sporadic forms of CJD have been identified. CJD typically results in global cognitive impairments, motor symptoms, and/or mood/behavioral changes. Different types of prion diseases can also be associated with psychological symptoms and behavioral changes. Additionally, specific variants of CJD can result in more prominent changes in particular cognitive domains, such as language and visual symptoms. Diagnosis of prion diseases is made based on results from different laboratory tests (e.g., spinal tap, neuroimaging, EEG), neurological examination, and other types of tests to rule out other possible causes for symptoms (e.g., neuropsychological assessment). However, a definitive diagnosis often cannot be made until post-mortem analysis of the brain tissue is able to be completed.

Please visit the following sites for more information regarding NCDs related to Prion Disease:


Parkinson’s Disease

Parkinson’s disease (PD) is a progressive neurological disorder that causes changes in motor movements, which may include tremor, rigidity, akinesia (absence of movement), postural instability (e.g., balance difficulties), and bradykinesia (i.e., slowed movements). In some cases, PD can progress to mild or major neurocognitive disorder, which typically occurs over a longer period (5-10+ years) of living with PD. Research has also suggested that changes in mood, such as increased symptoms of depression and/or apathy, can precede motor symptoms, though can also become more apparent following the onset of motor symptoms. NCD due to PD and Dementia with Lewy Bodies (DLB) share many common symptoms and have overlapping features in terms of their pathological progression. Completing a comprehensive evaluation, typically including a neurological examination, neuroimaging, and neuropsychological assessment, can be helpful in determining the most appropriate diagnosis and planning treatment. However, determining a definitive diagnosis between PD-related dementia and DLB can be difficult.

Please visit the following sites for more information regarding NCDs related to Parkinson’s disease:

Huntington’s Disease

Huntington’s disease (HD) is a neurodegenerative disorder that results in involuntary movements, behavioral and personality changes (e.g., depression, anxiety, apathy, withdrawal, anger/irritability), and cognitive changes (e.g., memory, attention/concentration, complex reasoning, planning/organizing). HD is a heritable disorder, meaning that it is passed from one generation to the next. Identification of the HD gene (HTT) has made it possible to determine who will develop HD. There is an approximately 50% chance that a parent with the HD gene will pass it to their child.  Symptoms typically present between ages 30-50, though juvenile cases have been identified. A diagnosis is typically made by a neurologist following a full neurological examination.

Please visit the following sites for more information regarding NCDs related to Huntington’s disease:

NCD due to Multiple Etiologies

In many cases, there are multiple identified causes for a particular neurocognitive disorder. Postmortem studies have found a significant number of patients with pathology consistent both with Alzheimer’s disease and vascular disease. In other cases, histories of substance use, traumatic brain injury, and vascular changes are each present and pose a contributing risk to the development of a neurocognitive disorder. In these cases, it is not possible to determine which etiology is the most prominent, as there are multiple potential causes for cognitive changes. In these cases, a diagnosis of neurocognitive disorder with multiple etiologies would be given. Further monitoring and/or additional testing (e.g., neuroimaging) may be warranted to help determine the best treatment options moving forward.

Resources vary based on multiple factors specific to each individual. As such, please ask your neuropsychologist directly for appropriate resources based on your individual needs/neuropsychological profile.

Unspecified Neurocognitive Disorder

The diagnoses of Other Specified Neurocognitive Disorder and Unspecified Neurocognitive Disorder are clinically indicated when a person exhibits characteristics of a neurocognitive disorder, but their presentation is complicated. One of the main reasons for this is that the individual does not meet full criteria for mild or major NCD, though are exhibiting mild symptoms that should be monitored with time.

Mental Health Disorders

According to the National Alliance on Mental Illness (NAMI): “A mental illness is a condition that affects a person’s thinking, feeling, behavior or mood. These conditions deeply impact day-to-day living and may also affect the ability to relate to others. If you have — or think you might have — a mental illness, the first thing you must know is that you are not alone. Mental health conditions are far more common than you think, mainly because people do not like to, or are scared to, talk about them.” Read more from NAMI on Mental Illness:

Read More

Depressive Disorders

Depressive Disorders are a set of diagnoses characterized by persistent feelings of sadness and worthlessness, as well as a lack of desire to engage in formerly pleasurable activities. Most people experience brief periods of a “down” mood. However, a depressive disorder is more severe and persistent. It is a very serious condition that can significantly interfere with all aspects of daily life, including daily tasks, interpersonal relationships, work, sleep, and aspects of cognitive functioning (e.g., processing speed). Professionals can treat depression with psychotherapy, medication, or a combination of both (most effective).

Major Depressive Disorder

Major Depressive Disorder (MDD) is diagnosed when an individual experiences persistent sadness, feelings of worthlessness, irritability, lethargy, sleep disruptions, and/or changes in appetite. These symptoms can also sometimes can include thoughts of death. While most people can feel sad or down from time to time, MDD extends far beyond normal unhappiness. Moreover, the persistence of a sad or irritable mood affects an individual’s thinking and behavior across settings, such as at home, in school, at work, and with friends. Early and consistent treatment reduces the severity of symptoms and decreases the risk of recurrence, while improving functioning and overall well-being.

Please visit the following sites for more information regarding Major Depressive Disorder:

Book recommendations from the Anxiety and Depression Association of America (ADAA) on depressive disorders can be found here:

Anxiety Disorders and Stressor-Related Disorders

Generalized Anxiety Disorder

Generalized Anxiety Disorder (GAD) is often diagnosed when an individual experiences persistent and chronic worry about multiple different areas (e.g., family, health, work, school, children, finances, etc.). As with depression, most people experience times where they worry about different situations or events. However, with GAD, these worries are excessive and difficult to control and are often accompanied by physical (e.g., gastrointestinal pain, muscle tightness), psychological (e.g., ruminative thoughts, indecisiveness, inability to relax, feeling on edge, etc.), and cognitive (e.g., trouble concentrating, trouble learning/remembering new information) symptoms. These symptoms can significantly interfere with areas such as interpersonal relationships, work, school, tasks at home, and self-care activities. Symptoms can present at any time, including in childhood or adulthood.

Please visit the following sites for more information regarding Generalized Anxiety Disorder:

Book recommendations from the Anxiety and Depression Association of America (ADAA) on anxiety disorders can be found here:

Posttraumatic Stress Disorder

Posttraumatic Stress Disorder (PTSD) is diagnosed following exposure to actual or threatened death, serious injury, or sexual violence either directly, by witnessing the event in-person as it occurred to others, learning that the traumatic event occurred to a close family member or close friend, or experiencing exposure to aversive details of traumatic events (e.g., first responders, police officers). Symptoms following these events may include intrusive memories, avoidance of reminders of the event, negative emotions (e.g., blaming oneself, negative beliefs about oneself or others, diminished interest in activities), and/or alterations in reactivity and physiological arousal (e.g., exaggerated startle response, increased irritability/angry outbursts, hypervigilance, etc.) persisting for more than one month following the traumatic event. PTSD symptoms can have significant impacts on daily activities and cognitive functioning, and evidence-based treatments such as Cognitive Processing Therapy and Prolonged Exposure can be very helpful at addressing these symptoms with time.

Please visit the following sites for more information regarding PTSD:

Book recommendations from the Anxiety and Depression Association of America (ADAA) on PTSD can be found here:

Bipolar Disorders

Bipolar Disorders are a set of diagnoses that causes unusual shifts in mood, energy, activity level, and concentration, which make it difficult to engage in daily tasks. Moods typically vacillate between periods of “highs,” such as feeling elated, irritable, or energized (known as manic episodes) to periods of “lows,” such as feelings of sadness, indifference, or hopelessness (known as depressive episodes). Less severe manic periods are known as hypomanic episodes.

Examples of mania and hypomania area generally the same, but vary in their degree of severity:

        • Higher-than-normal energy levels
        • Restlessness or inability to sit still
        • Decreased need for sleep
        • Increased self-esteem or confidence, or grandiosity
        • Extremely talkative
        • Racing thoughts
        • New ideas and plans
        • Easily distracted
        • Taking on multiple projects with no way of finishing them
        • Decreased inhibitions
        • Increased sexual desire
        • Engaging in risky behavior, such as having impulsive sex, gambling with life savings, or going on big spending sprees
Bipolar I and II Disorder (formerly called manic-depressive illness or manic depression)

Bipolar I Disorder is diagnosed when there is a distinct period (one week or longer) of manic symptoms so pronounced that the person may require hospital care. Depressive episodes also occur and last for a minimum of two weeks. Periods of mixed features (manic and depressive symptoms) can also occur.

Bipolar II Disorder is diagnosed when there is a pattern of depressive and hypomanic symptoms without mania. There must be one or more major depressive episode and at least one hypomania episode. The hypomanic episode must last for most of the day each day for at least four days.

Please visit the following sites for more information regarding Bipolar I and Bipolar II Disorder:

Book Recommendations:

The Bipolar Disorder Survival Guide, Third Edition: What You and Your Family Need to Know 3rd Edition by David Miklowitz

*HNS does not endorse any specific treatments, procedures, or products referenced in our Resources pages. This information is intended for use as an educational resource and is not intended to serve as professional advice. You and your neuropsychologist will work together to better understand your specific symptoms and history to determine the most appropriate treatment plan moving forward.