Depression is characterized by feelings of hopelessness and helplessness, a loss of interest in regular daily activities, anger, irritability and a sense of self-loathing, according to Helpguide.org. Changes in weight, appetite and sleep patterns, reckless behavior and loss of energy are also indicators of depression.
Some people have trouble concentrating when depressed, and tasks that were once easy become difficult. They may have a feeling of being unable to control negative thoughts, and they may feel as if their lives are not worth leading. When feelings of worthlessness surface, immediate mental health help is needed.
An increase in alcohol consumption can also be an indicator of depression. A depressed individual may exhibit escapist behaviors, such as doing drugs, driving recklessly, participating in high-risk sports activities and compulsively gambling. Depression may manifest itself with an increase in perceived pains and aches, including back pain, stomach pain, muscle aches and headaches.
Feelings of guilt and self-loathing are often characteristic of depression. The depressed person may criticize himself harshly and make note of his perceived mistakes and faults. The person may have a bleak outlook and feel that nothing could possibly bring an improvement to his current situation, notes Helpguide.org.