Delusional disorder, previously called paranoid disorder, is a type of serious mental illness — called a “psychosis”— in which a person cannot tell what is real from what is imagined. The main feature of this disorder is the presence of delusions, which are unshakable beliefs in something untrue.
Obsessive-compulsive disorder (OCD) is a disorder in which people have recurring, unwanted thoughts, ideas or sensations (obsessions) that make them feel driven to do something repetitively (compulsions).
Bipolar disorder (manic-depressive disorder). Bipolar disorder is defined by swings in mood from periods of depression to mania. When someone experiences a low mood, symptoms may resemble those of a clinical depression.
Obsessive-compulsive personality disorder (OCPD) is a personality disorder that's characterized by extreme perfectionism, order, and neatness. People with OCPD will also feel a severe need to impose their own standards on their outside environment.
Depression (major depressive disorder) is a common and serious medical illness that negatively affects how you feel, the way you think and how you act. Fortunately, it is also treatable. Depression causes feelings of sadness and/or a loss of interest in activities you once enjoyed.
