Physical Health and Mental Health

Although mental health problems may be due to psychological stressors, and to the impact of recognised mental illnesses such as schizophrenia, depression and obsessive compulsive disorder, mental health fundamentally relies on the health of the brain. Therefore, any condition that affects the brain as a part of the body may also impact on functions of the brain such as memory, mood, sensory perceptions, thought processes, concentration, motor skills and communication. This may impair a person’s ability to manage in challenging or unfamiliar situations or may present as a mental illness. People with an intellectual disability may be more vulnerable to the effects of physical illness on their brains. They may also be at increased risk of medical illness due to common factors underlying both conditions. For instance, someone with intellectual disability due to cerebral palsy may also have swallowing issues leading to a risk of aspiration peumonia.

Depression

Longstanding physical illness of any kind carries with it an increased risk of depression, particularly where chronic pain is involved. Other physical issues that may increase the risk of depression include hypothyroidism and nutritional deficiencies, and numerous medications may have depression as a side effect. Depression may also develop after a brain injury or as a consequence of prolonged alcohol or substance abuse.

Mania

Several medications also predispose to mania: most notably the antidepressants but also other medications such as steroids (commonly used in asthma or other immune system disorders). Mania may also be triggered by the use of prescribed stimulants such as Ritalin or illegal amphetamines.

Anxiety

Anxiety may be associated with hyperthyroidism, and can also be associated with the excessive use of caffeine, or the use of asthma reliever medication, among others.

Psychosis

Usually, if psychosis is due to a physical health problem, this will be in the context of a delirium (see next page). However, brief espides of psychosis may also occur as a result of substance use or prescribed medications.