Share this infographic on your site!

The Science of Mental Illness

Embed this infographic on your site!

The editors at Best Masters in Psychology Degrees decided to research the topic of:


More than 50 million Americans suffer from a mental illness or mental disorder. Because most of them are not severe and many go untreated, it may be helpful to understand the science behind what causes mental illness and how it manifests itself in everyday life.

Picture of Mental Health

1 in 4

- Adults with a mental illness


- Those with a mental disorder who are receiving treatment

$57.5 billion

- Annual mental healthcare costs

Nearly 1 in 2

- People with mental disorders who fit the criteria for multiple disorders
- Mood disorders - 9.5%
- Major depressive disorder - 6.7%
- Dysthymic disorder - 1.5%
- Bipolar disorder - 2.5%
- Anxiety disorders - 18.1%
- Panic disorder - 2.7%
- Obsessive-compulsive disorder - 1.0%
- Post-traumatic stress disorder - 3.5%
- Generalized anxiety disorder - 3.1%
- Social phobia - 6.8%
- Schizophrenia - 1.1%

What Happens in the Brain

Scientists who study mental illness believe an imbalance in brain chemicals contributes to the development of many disorders. Researchers suspect this imbalance impedes the brain's ability to move messages from neuron to neuron and for the brain's wiring to function normally. As a result of this breakdown, the brain may not communicate properly with the body, and a person may begin to show signs of mental illness.

Different chemicals have been associated with a variety of mental disorders:


- Too much: Depression
- Too little in the hippocampus: Dementia


- Too much: Schizophrenia
- Too little: Some forms of depression, muscular rigidity and tremors found in Parkinson's disease


- Too much: Schizophrenia
- Too little: Depression


- Too little: Depression


- Too little: Depression and some anxiety disorders, especially obsessive-compulsive disorder. Some antidepressant medications increase the availability of serotonin at receptor sites.

GABA (Gamma-Amino Butyric Acid)

- Too little: Anxiety and anxiety disorders. Some anti-anxiety medication increases GABA at receptor sites.


- Too much: Anxiety and anxiety disorders

What Happens in the Body

Mental illnesses may manifest themselves in a variety of ways for different people, but many symptoms are common.

Anxiety disorders

- heartbeat
- Lightheadedness
- Burning sensation on face, neck, ears, scalp or shoulders
- Nausea
- Twitching
- Weight loss/weight gain


- Headaches
- Back pain
- Muscle aches and joint pain
- Insomnia
- Chest pain
- Change in appetite


- Blank, vacant facial expression
- Overly acute senses
- Clumsy, inexact motor skills
- Insomnia or excessive sleeping
- Involuntary movements of the tongue or mouth
- Awkward gait