Depression can be characterized as a feeling of sadness or emptiness that lasts for at least two weeks and is experienced most of the day, most days. Usually, there are additional problems that include a loss of interest in pleasurable aspects of life, trouble with concentration or short-term memory, appetite changes, sleep problems, changes in sexual interest, and hopelessness/helplessness/worthlessness/ guilt.
Anxiety is usually characterized by chronic and hard-to-control worrisome thoughts, tension in the muscles, stomach problems, tingly in the hands or feet, irritability, problems with sleep, and a feeling of being keyed up.
Phobias are fears, quite extreme, to specific situations, events, or objects. If a phobia exists, usually the person tries to avoid the trigger, or if avoidance cant be accomplished then there is strong anxiety in anticipation of the trigger. Phobias to performing socially, meeting strangers, or certain animals are common.
Panic is an anxiety attack usually lasting 20 or 30 minutes, often accompanied with thoughts of dying or losing ones mind, and sometimes occurring away from home, in crowds, or in open spaces. Usually someone with panic will begin to stay close to home and overly monitor their internal processes such as heart-rate or breathing.
Obsessive-Compulsive Disorder is a frequent intrusive set of ideas that trigger anxiety and that can not easily be controlled. The anxiety is often reduced if the person performs certain routines or rituals, and these rituals can be overt behaviors or internal mental activities (such as repeatedly saying a word or prayer). OCD usually consumes well over one-hour per day thinking the obsessive thoughts or acting on the urges to perform the routines.
Habit Disorders are typically destructive behaviors that develop because of their tendency to reduce stress while being performed. Examples of more common habit disorders include skin picking and trichotollomania (hair pulling).
Adjustment Disorders are short-term (less than six months) reactions that are unhealthy, in response to identifiable stressors. The problems can be experienced as depression, anxiety, or behavioral outbursts, or a combination of these.