The early signs of depression occur during times of stress. During these times of stress, then you have to look at your thoughts and reactions to these stressors. It is these thoughts and reactions to stress that determine if you will go on to develop depression or anxiety.
As an example, let’s say you are having stress on the job, where your boss is making unrelenting demands and is invalidating. So this job stress may induce thoughts, where you might think all is hopeless, and that you can’t handle the stress.
These negative thoughts then induce feelings of depression, and you may then get the associated fatigue, apathy, and The Blues. The depression then leads to social withdrawal, where you isolate yourself, withdraw from others, and put off work deadlines. Although these avoidant behaviors make you feel less depressed over the short term, over the long term, it maintains and perpetuates your thoughts that all is hopeless and that you can’t cope with the stress.
Thus, your negative thoughts and avoidant behaviors both initiate and maintain this depressive cycle. So the early signs of depression are negative thoughts to stressors and social isolation. As the depression evolves and develops, then you may also start to notice changes in your sleep patterns, appetite, concentration, and energy level.