'Depression' covers a lot of ground, but refers to a range of mental health conditions. Typically, though, we're talking about low mood, negative affect, difficulty in maintaining interest and concentration…
Depression: A heavy 'chainmail duvet' of exhaustion. You feel, quite literally, pressed down
"… the single most destructive thing about depression [is that with] most other illnesses, at least you still have your mind: to think about recovery, to plot a rehabilitation programme, to distract you from your agonies in books, or music, or film or daydreaming. With your mind intact there's a lot you can still do, however ill you are.
But when it is the mind that is ill, thinking can't come to your help. In fact, the opposite. Thinking is like quicksand; the more you do, the deeper you descend"
You've lost your initiative, your ability and willingness to engage in activities. You can't bear doing the things you used to love. You can't enjoy a meal, if only because you know that when you've finished it, you'll have the rest of the day to face. Days repeat themselves, deathly still, colourless. Hours drag by so slowly, but weeks seem to multiply.
You want to do these things to fulfill your responsibilities, but it takes such tremendous effort. It's as if you're moving through thick mud just to be mobile, just to get things done that previously took little energy or effort. And the effort it takes now just to live, just to do the basic chores and tasks of life, requires so much more energy than ever before.
You feel quite literally pressed down.
In Cognitive Behavioural Therapy (CBT), Aaron Beck's theory of depression would have it that the condition derives from an all-pervasive sense of loss — a sense of regarding oneself as "lacking some element or attribute that [one] considers essential for…happiness". This feeds into a "cognitive triad" of negative distortions.
It begins with a biased view of oneself as inadequate — a loser, "all washed up".
It then expands to encompass the view that everyone you interact with sees you as equally 'unloveable' and unworthy of respect or admiration.
And finally, you come to hold this view of yourself as defective as something which will last forever — your future is hopeless.
Depression, for Beck, has a specific "chonology" which precipitates a "chain reaction" leading to "inertia, fatigability, agitation" and other negative cognitions resulting in conclusions of "self-defectiveness" - (Aaron T. Beck, Cognitive Therapy and the Emotional Disorders)
Depression can be divided into three large categories: major depressive disorder, bipolar disorders and dysthymic disorder.
Major Depressive Disorder is what most people think of when they think of depression: tearfulness, loss of interest, weight loss or gain, inability to get to sleep, or desire to sleep all the time, loss of energy and initiative, feelings of worthlessness or guilt, inability to concentrate or sustain attention, feeling slowed down or keyed up, thoughts of death or suicide, irritability, feelings of emptiness, and feelings of hopelessness.
Bipolar Disorder has all the characteristics of Major Depressive Disorder, but for periods of time the person feels elated, grandiose, energetic, angry or irritable in between periods of great sadness and loss of energy.
The two "poles" of energy and lethargy, sadness and anger, loss of initiative and hyperactivity, inability to function and inability to stop, shame and "superpower" (either with aggression and inability or with unwarranted elation and ebullience) come and go in cycles over time.
In cyclothymic disorder (the "little brother" of bipolar disorder), you don't lose contact with your typical self, but go through cycles of no energy and inappropriately high energy. With cyclothymic disorder your symptoms don't quite make the mark for a bipolar disorder, but do exhibit variablity in mood that is marked and interferes with your ability to function.
Bipolar disorders are definitely considered neurochemical imbalances, and most evidence suggests that bipolar disorders are inherited genetically. The fact that bipolar disorders have a neurochemical basis makes them even more confusing. You feel strongly, but can't easily discrimiate if the feeling is based on an objective environmental event that prompts the feeling, or is a direct reflection of the chemical imbalance.
More than other disorders, bipolar disorders make you distrust your emotions (and for good reason, since sometimes you feel very strongly with no event from the environment making you feel this way).
With Dysthymic Disorder you don't feel the full force of a major depressive episode where it's almost impossible to take action or get anything done.
But dysthymic disorder does make life feel like a constant struggle — a struggle that has gone on for very long periods of time. Pessimism, lack of energy and loss of hope have become normal, and you have become so accustomed to theis state of affairs that anything else would seem alien.