He tars his life, people around him, his experiences, places, memories with a thick layer of schmaltzy, sentimental sadness and longing. In this sense, the depressive is cognitively distorted. He interprets his experiences, evaluates his self and assesses the future totally negatively. No success or support can break this cycle because it is so complete and self-enhancing. This is a cozy little circle, charmed and protective because it is predictable, never failing and available - the properties of the missing parent.
Depression is addictive because it is a strong love substitute.
Much like drugs, it has its own rituals, language and worldview. It imposes schedules and behavior patterns on the depressive. This is learned helplessness - the depressive prefers to avoid situations even if they hold the promise of improvement. He has been conditioned by repeated aversive stimuli to freeze - he does not even have the energy needed in order to escape from a cruel world. The depressive is devoid of the positive reinforcements, which are the building blocks of our self-esteem.