rder Not everyone who is depressed or manic experiences every symptom. Some people experience a few symptoms, some many. Also, severity of symptoms varies with individuals. Here are some of the possible symptoms of major depression and bipolar disorder. Major Depression: Persistent sad, anxious, or "empty" mood Feelings of hopelessness, pessimism Feelings of guilt, worthlessness, helplessness Loss of interest or pleasure in hobbies and activities that were once enjoyed, including sex Insomnia, early morning awakening, or oversleeping Appetite and/or weight loss or overeating and weight gain Decreased energy, fatigue, being "slowed down" Thoughts of death or suicide; suicide attempts Restlessness, irritability Difficulty concentrating, remembering, making decisions Persistent physical symptoms that do not respond to treatment, such as headaches, digestive disorders, and chronic pain Bipolar Disorder: Inappropriate elation Inappropriate irritability Severe insomnia Grandiose notions Increased talking Disconnected and racing thoughts Increased sexual desire Markedly increased energy Poor judgment Inappropriate social behavior Causes Of Depression The causes of depression have not yet been established and explanations for the occurrence of the disorder vary to the theoretical method that is applied to it. Biological, family, and social factors have all been found to play a role in the disorder. Depression may be most clearly seen as occurring due to both biological and environmental factors. The biological theory of depression postulates that the disorder is caused by a deficiency in one or more neurotransmitters, most likely serotonin and norepinenphrine, and possibly dopamine. Support for this theory comes from the fact that drugs that potentate the effects of these neurotransmitters tends to result in a decrease in depressive symptoms in most patients. Psychological theories of depression vary greatly in their explanation of the disorder...