Everyone become depressed from time to time. The loss of a loved one, the end of a relationship or losing job can have a person feeling blue and down in the dumps. However, there is a difference between simply feeling depressed and suffering from clinical depression. Knowing the symptoms of the disease can potentially save a life once medical attention is sought. One of the most basic symptoms of depression is the inability to concentrate. You may find yourself at work or doing a simple task such as watching TV at home but find yourself unable to adequately focus on what you are doing. Along with difficulty in concentrating, you may also find it hard to make decisions, and your memory may fail you, especially where details are concerned. Your sleep is often irregular when you are suffering from clinical depression. This is a very common symptom. You may find it difficult to fall asleep, or once you have fallen asleep, you may waken periodically throughout the night and have trouble staying asleep, even when you are exhausted both physically and mentally. Insomnia is a very common feature of depression, although when you do sleep, you may find yourself awaking very early in the morning. Another common symptom of depression is a feeling of anxiety, sadness and hopelessness. You will most likely find it difficult to smile or laugh, even at situations that are genuinely funny. When you suffer from depression, it is not uncommon to have a vast decrease in energy. You will find yourself feeling fatigued all the time, often exhausted and unable to perform even the most basic everyday activities. Aches and pains are also a common symptom of depression, including cramps, aches and pains and problems with your digestion that persist even when you get treatment for them. Individuals who have clinical depression typically also experience a loss of interest, even in activities that once brought them pleasure. You will find that your hobbies no longer mean as much to you as they once did.