Personality disorders: People with personality disorders have extreme and inflexible personality traits that are distressing to the person and/or cause problems in work, school, or social relationships. In addition, the person's patterns of thinking and behaviour significantly differ from the expectations of society and are so rigid that they interfere with the person's normal functioning. Examples include antisocial personality disorder, obsessive-compulsive personality disorder, and paranoid personality disorder.
Obsessive-compulsive disorder (OCD): People with OCD are plagued by constant thoughts or fears that cause them to perform certain rituals or routines. The disturbing thoughts are called obsessions, and the rituals are called compulsions. An example is a person with an unreasonable fear of germs who constantly washes his or her hands.
Dissociative disorders: People with these disorders suffer severe disturbances or changes in memory, consciousness, identity, and general awareness of themselves and their surroundings. These disorders usually are associated with overwhelming stress, which may be the result of traumatic events, accidents, or disasters that may be experienced or witnessed by the individual. Dissociative identity disorder, formerly called multiple personality disorder, or "split personality," and depersonalization disorder are examples of dissociative disorders.
Factitious disorders: Factitious disorders are conditions in which a person knowingly and intentionally creates or complains of physical and/or emotional symptoms in order to place the individual in the role of a patient or a person in need of help.
Tic disorders: People with tic disorders make sounds or display no purposeful body movements that are repeated, quick, sudden, and/or uncontrollable. (Sounds that are made involuntarily are called vocal tics.) Tourette's syndrome is an example of a tic disorder.
Alien Hand Syndrome: This syndrome is characterized by the belief that one’s hand “does not belong to oneself, but that it has its own life,” Medscape says. Individuals experiencing alien hand syndrome have normal sensation but feel their hand is autonomous, with a “will of its own.” Those with alien hand syndrome may personify the limb as a separate entity: the unaffected hand is under the individual’s control while the affected hand has its own agenda. This syndrome may occur in individuals who have damage to the corpus callosum, which connects the two cerebral hemispheres of the brain. Other causes include stroke and damage to the parietal lobe. The hands then appear to be in “intermanual conflict” or “ideomotor apraxia,” meaning they act in opposition to one another.
Capgras Syndrome: This syndrome is named for Joseph Capgras, a French psychiatrist who explored the illusion of doubles. Those with Capgras syndrome hold the delusional belief that someone in their life, usually a spouse, close friend or family member, has been replaced by an impostor. It can occur in patients with schizophrenia, dementia, epilepsy and after traumatic brain injury. Treatment approaches mirror those utilized for the underlying disorders and often include antipsychotic medications.
Apotemnophilia: Also known as body integrity identity disorder, apotemnophilia is characterized by the “overwhelming desire to amputate healthy parts of [the] body,” according to Medscape. Though not much is known about it, this disorder is believed to be neurological. Those affected may attempt to amputate their own limbs or damage the limb so that surgical amputation is necessary. Apotemnophilia may be related to right parietal lobe damage in the brain. The condition is challenging to treat because people experiencing it often do not seek treatment. However, both cognitive behavioural therapy and aversion therapies can be attempted in order to treat apotemnophilia once treatment is sought.
Stendhal Syndrome: Those with Stendhal syndrome experience physical and emotional anxiety as well as panic attacks, dissociative experiences, confusion and hallucinations when exposed to art. These symptoms are usually triggered by “art that is perceived as particularly beautiful or when the individual is exposed to large quantities of art that are concentrated in a single place,” such as a museum or gallery, Medscape says. However, individuals may experience similar reactions to beauty in nature. This syndrome is named after a 19th-century French author who experienced the symptoms during a trip to Florence in 1817. Stendhal syndrome may also be called hyperculturemia or Florence syndrome.