Hi Lisa, 9/8/08
I am a Clinical Psychologist and long time depression sufferer. Without more info I cannot be absolutely sure, however you described 3 important symptoms which can be indicative of depression: racing thoughts, mood swings, and irritability. Between the lines I think I got the sense of another symptom: anhedonia, or the loss of enjoyment in day-to-day life. If you are depressed, you will also have a sleep disturbance, loss of interest in previously cherished activities, and a loss of productivity (i.e., whether that is on the job or in school). I am assuming that you are not suffering from hyperactivity, and no one has told you that you may have ADHD (i.e., Attention Deficit Disorder with Hyperactivity). Your age is important in regard to this question.
More information is needed to examine whether your condition is situational or more long term. I inherited my depression (and anxiety) genetically, which is very common, and long term. Of the 4 children in my family, 3 out of the 4 developed depression either in adolescence (i.e., me), or young adulthood (i.e., my sister and brother). Situational depression results from some insurmountable block to cherished goals in one's life (e.g., lose a job you love, turned down by a college for entrance). The origin of your depression, and length of time you have been suffering from your symptoms would determine whether medication is necessary. Short-term situational depression is best treated by professional counseling (i.e., helpful advice from well-meaning relatives or friends doesn't help; Don't you agree?!). Medication can help in this situation, but only as an adjunct to the counseling because you have to solve the dilemma that is causing the situational depression. Most county mental health centers offer a siding scale to pay for this counseling, and it may only last 10 weeks or less, going once a week. They usually will let you make small monthly payments. This is if you do not have medical insurance, in which case the counseling could be free, or you could pay a small co-payment.
If there is no situation which precipitated your depression, it is biochemical in its inception, and will almost certainly require medication to relieve your symptoms. One caution must be added for more long term depression, or if the condition resulted from some kind of injury. There is a condition called Bipolar Disorder which includes all of the symptoms you have described. You usually inherit this condition genetically. Some young people with ADHD can graduate into the disorder. Medical tests are required to make the diagnosis, although other mental health practitioners can help point you in the right direction.
If you are a young person (i.e., under 13), and are not necessarily depressed, you may have ADHD, which, along with your mentioned symptoms would include a sleep disturbance, inability to concentrate, distractability, a sense that you are thinking and acting faster than most other people around you, and no desire to put up with others who cannot keep up with you. This is a biochemical disorder, and requires medication in order to function in school. Also, your parents must approve of the medication. There is an argument about the medication because of side effects and long term effects, however if one cannot learn in school, medication is indicated because all young people have stages of development, which are times in one's life in which one must learn some things. For example, one must learn to read before age 14 or generally they will always be a slow reader. It is as if a door shuts to that kind of learning.
I hope I have been helpful in your quest to find out why you are not functioning the way you used to. I hope you get to be diagnosed by a mental health professional, or even your family doctor. If you are over the age of 12, the appointment will be confidential. As you see, there are many symptoms and determinents which must be factored in. Good luck. RAR1951