An estimated one in five Americans have a mental disorder and, in 2011, about 11.4 million adults in the United States suffered from serious mental illness. Of those, 8.7 million admitted to thoughts of suicide, two million made suicide plans and one million attempted suicide.

Mental illness can take many forms, ranging from the more common instances of depression or Obsessive Compulsive Disorder to the rare and strange, such as Alien Hand syndrome.

AHS is a rare illness in which one hand functions involuntarily with the victim completely unaware of its actions. Symptoms include involuntary reaching or grasping, touching the face, tearing at clothes, involuntarily stuffing food into the mouth, preventing the normal hand from completing tasks and even self-inflicted punching or choking. Since AHS was first identified in 1909, there have only been 40-50 cases reported.

In this infographic, PsychDegrees.org takes an in-depth look at five of the strangest mental disorders.

5 Strangest Mental Disorders

Source: 5 Strangest Mental Disorders