What is Psychiatric Disability and Mental Illness?


Definition of Mental Illness and Some Common Diagnoses*

Mental illness is a term that describes a broad range of mental and emotional conditions. Mental illness also refers to one portion of the broader ADA term mental impairment, and is different from other covered mental impairments such as mental retardation, organic brain damage, and learning disabilities. The term ‘psychiatric disability’ is used when mental illness significantly interferes with the performance of major life activities, such as learning, working, and communicating, among others.

Someone can experience a mental illness over many years. The type, intensity, and duration of symptoms vary from person to person. They come and go and do not always follow a regular pattern, making it difficult to predict when symptoms and functioning will flare-up, even if treatment recommendations are followed. The symptoms of mental illness often are effectively controlled through medication and/or psychotherapy, and may even go into remission. For some people, the illness continues to cause periodic episodes that require treatment. Consequently, some people with mental illness will need no support, others may need only occasional support, and still others may require more substantial, ongoing support to maintain their productivity.

The most common forms of mental illness are anxiety disorders, mood disorders, and schizophrenia disorders. Brief introductory information about these conditions is presented in this section for educational purposes only.

Anxiety Disorders

Anxiety disorders, the most common group of mental illnesses, are characterized by severe fear or anxiety associated with particular objects and situations. Most people with anxiety disorders try to avoid exposure to the situation that causes anxiety.

  • Panic disorder – the sudden onset of paralyzing terror or impending doom with symptoms that closely resemble a heart attack
  • Phobias – excessive fear of particular objects (simple phobias), situations that expose a person to the possible judgment of others (social phobias), or situations where escape might be difficult (agoraphobia)
  • Obsessive-compulsive disorder – persistent distressing thoughts (obsessions) that a person attempts to alleviate by performing repetitive, intentional acts (compulsions) such as hand washing
  • Post-traumatic stress disorder (PTSD) – a psychological syndrome characterized by specific symptoms that result from exposure to terrifying, life-threatening trauma, such as an act of violence, war, or a natural disaster

Mood Disorders

Mood disorders are also known as affective disorders or depressive disorders. These illnesses share disturbances or changes in mood, usually involving either depression or mania (elation). With appropriate treatment, more than 80% of people with depressive disorders improve substantially.

  • Major depression – an extreme or prolonged episode of sadness in which a person loses interest or pleasure in previously enjoyed activities
  • Bipolar disorder (also referred to as manic-depressive illness) – alternating episodes of mania (“highs”) and depression (“lows”)
  • Dysthymia – continuous low-grade symptoms of major depression and anxiety
  • Seasonal affective disorder (SAD) – a form of major depression that occurs in the fall or winter and may be related to shortened periods of daylight

Schizophrenia Disorders

Research has not yet determined whether schizophrenia is a single disorder or a group of related illnesses. The illness is highly complex, and few generalizations hold true for all people diagnosed with schizophrenia disorders. However, most people initially develop the symptoms between the ages of 15 and 25. Typically, the illness is characterized by thoughts that seem fragmented and difficulty processing information.

Symptoms of schizophrenia disorders are categorized as either “negative” or “positive.” Negative symptoms include social isolation or withdrawal, loss of motivation, and a flat or inappropriate affect (mood or disposition). Positive symptoms include hallucinations, delusions, and thought disorders.

*Adapted from Zuckerman, D., Debenham, K., & Moore, K. (1993). The ADA and People with Mental Illness: A Resource Manual for Employers. Available from the National Mental Health Association, 1021 Prince Street, Alexandria, VA 22314-2971, (703)684-7722.


“English” Examples of Disclosing a Mental Illness

The Equal Employment Opportunity Commission (EEOC) has published new Enforcement Guidance on the ADA and People with Mental Illness. In it, the EEOC states that someone who has a mental illness can tell their employer about the illness using “English.” This means that the employee is not required to use certain terms, such as clinical diagnoses, mental illness or psychiatric disability to disclose mental illness and request accommodations. Some examples of the terms and phrases that an employer may hear are:

  • I have a medical condition that requires more frequent breaks to do my work.
  • I need some time off or a leave of absence because I am stressed and depressed.
  • I take medication for a disorder that makes it difficult to get up early in the morning.

If the employee’s need for accommodation is not obvious to the employer, the employer can ask for documentation of the disability and functional limitations by a professional. Similarly, most teachers may not have specific information about the diagnosis, but Disability Services Offices in colleges and universities require professional documentation of the disability. You can read a Summary of the EEOC Guidance on this site in the Laws section, or read the full text on the EEOC site. It can also be obtained from your regional Disability and Business Technical Assistance Center, (800)949-4232.

Characteristics of Psychiatric Disability that Affect Functioning

The irregular nature of mental illness – The irregular nature of mental illness may create problems in establishing or maintaining consistent work or school patterns. Some individuals may need time off for medical appointments or to recuperate. The irregular nature of mental illness might also impair an individual’s performance.

Stress associated with non-disclosure – Anxiety often accompanies the effort to hide an illness and its symptoms. Many individuals do not disclose an illness for fear of stigma and discrimination. This fear may be compounded if an employee feels that a job is in jeopardy or a student worries that admission may not be offered.
Side effects of medications – Despite their effectiveness for many people, medications also can have side effects that create difficulties at work or in school. Each person has an adjustment period after starting, changing the dose of, or stopping medication. Some of the most common side effects include:

  • drowsiness
  • dizziness
  • dry mouth
  • nervousness
  • headaches
  • shakiness
  • confusion
  • weight gain

Interrupted education or training – Many people first develop symptoms of mental illnesses between the ages of 15 and 25 and traditional educational or vocational training may be delayed. This may affect their credentials for jobs or educational programs.

Co-morbidity – The National Institute of Mental Health (NIMH) reports that 30% of adults with a mental illness also have had a diagnosable alcohol and/or drug abuse disorder during their lives. In addition, 53% of adults who have had substance abuse disorders have had one or more mental illnesses during their lifetimes. Treatment and accommodation in these cases address both the effects of substance abuse as well as the effects of the person’s mental illness.

Note: The information contained in these pages is for educational purposes only, and is not legal advice. Individuals should contact the appropriate legal resources for specific legal advice regarding their particular situations.