Mental disorder or usually known as mental illness is generally a psychological matter that reflected in behavior, which is not considered as a normal development of a person because of several terms such as distress or disability. Mental disorder itself is usually defined by combination of how a person feels, acts, thinks or perceives. This may be connected or related with functions of the brain or rest of the nerve system. The causes of mental disorder are varied, depend on the cases, but mostly are environmental matters that give the greater impacts for the causes of disorder.
Mental disorder is classified into several terms such as anxiety or fears may also be classified as an anxiety disorders, which have phobia as the most common cases, personality, the characteristic of a person that can influence thoughts and behaviors in certain situations and times, for example paranoid, eating disorders, involve disproportionate concern in food and weight, sleep disorders, who has unusual sleep pattern, sexuality, more like a gender identity disorder, for example paraphilia and many others. There are also some new types that are considered as mental disorder such as sadistic personality disorder.
The cure and symptoms are not decided in some specific time but all depends on the person and also the environment itself, because the environmental thing has the biggest impact in building a personality process of the person and the people in the surroundings are the one who can help the cure process, and also no other that themselves.
References: http://en.wikipedia.org/wiki/Mental_disorder
