10% of the population of children and youth. Children and youth affected by mood and anxiety disorders. Poor self-esteem or guilt: withdrawal from friends and activities, changes in eating or sleeping patterns. Related to chemical imbalance in the central nervous system. Associated with decreased levels of neurotransmitters such as serotonin. However, it is not simply a lack of serotonin. Defined by marked changes in mood and energy. Bipolar is associated with fluctuation in neurotransmitters which affect the hypothalamus (central role in emotion regulation) Confusion, lack of coordination, frequent urination, dehydration, thyroid problems. May develop after an individual experiences a traumatic event such as; Posttraumatic stress disorder (ptsd) sexual or physical assault witnessing a death natural disaster terrorist attack. Reexperiencing the event, which can take the form of intrusive thoughts and recollections, or recurrent dreams. Hypersensitivity, including: inability to sleep, anxious feelings, overactive startle response, hypervigilance, irritability and outbursts of anger.