Depression (major depressive disorder or clinical depression) is a common, but serious mood disorder. It causes severe symptoms that will affect how one feels, thinks, and handles daily activities, such as sleeping, eating or working.
Occasional anxiety is an expected part of life. You might feel anxious when faced with a problem at work, before taking a test, or before making important decisions. But anxiety disorders involve more than temporary worry or fear. For a person with an anxiety disorder, their anxiety does not go away and can get worse over time. The symptoms can interfere with daily activities such as job performance, school work or relationships.
There are several types of anxiety disorders, including generalized anxiety disorder, panic disorder, and various phobia-related disorders.
Panic disorder is a form of anxiety disorder and is characterized by unexpected and repeated episodes of intense fear accompanied by physical symptoms that may include chest pain, heart palpitations, shortness of breath, dizziness, or abdominal distress.
Attention-deficit/hyperactivity disorder is a brain disorder marked by an ongoing pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development.
Obsessive-Compulsive Disorder (OCD) is a common, chronic and long lasting disorder in which a person has uncontrollable, reoccurring thoughts (obsessions) and behaviors (compulsions) that he or she feels the urge to repeat over and over.
Post-traumatic stress disorder (PTSD) can develop after exposure to a potentially traumatic event that is beyond a typical stressor. Events that may lead to PTSD include, but are not limited to, violent personal assaults, natural or human-caused disasters, accidents, combat, and other forms of violence. Exposure to events like these are common. About one half of all U.S. adults will experience at least one traumatic event in their lives, but most do not develop PTSD. People who experience PTSD may have persistent, frightening thoughts and memories of the events, experience sleep problems, feel detached or numb, or may be easily startled. In severe forms, PTSD can significantly impair a person's ability to function at work, at home, and socially.
Bipolar disorder, also known as manic-depressive illness, is a brain disorder that causes unusual shifts in mood, energy, activity levels, and the ability to carry out day-to-day tasks.
Personality disorders represent “an enduring pattern of inner experience and behavior that deviates markedly from the expectations of the individual’s culture” per the Diagnostic and Statistical Manual on Mental Disorders, Fifth Edition (DSM-5). These patterns tend to be fixed and consistent across situations and lead to distress or impairment.
Borderline personality disorder is a serious mental disorder marked by a pattern of instability in moods, behavior, self-image, and functioning. These experiences often result in impulsive actions and unstable relationships. A person with borderline personality disorder may experience intense episodes of anger, depression, and anxiety that may last from only a few hours to days.
Schizophrenia is a chronic and severe mental disorder that affects how a person thinks, feels, and behaves. People with schizophrenia may seem like they have lost touch with reality. Although schizophrenia is not as common as other mental disorders, the symptoms can be very disabling.
The word psychosis is used to describe conditions that affect the mind, where there has been some loss of contact with reality. When someone becomes ill in this way it is called a psychotic episode. During a period of psychosis, a person’s thoughts and perceptions are disturbed and the individual may have difficulty understanding what is real and what is not. Symptoms of psychosis include delusions (false beliefs) and hallucinations (seeing or hearing things that others do not see or hear). Other symptoms include incoherent or nonsense speech and behavior that is inappropriate for the situation. A person in a psychotic episode may also experience depression, anxiety, sleep problems, social withdrawal, lack of motivation, and difficulty functioning overall.
* Definitions provided by National Institute of Mental Health