What is the difference between lack of concentration caused by adhd and that caused by depression?

History: The concentration problems of add have been present to some degree throughout one's life. Depression is usually episodic. If it is associated with diminished concentration, that will clear up when the depression does.

See below...: When lack of concentration is due to depression, it usually has a lack of interest, blah & down mood about it. When it is due to adhd, mood is not affected & the person is usually pretty energetic...

Adhd: In depression you have other symptoms of depression and don't feel like doing the task. In adhd you are frustrated & feel you can't do it.

Same and different: The inability to concentrate itself, no significant difference.The duration of symptoms, mood, affect , and accompaning symptoms quite different.

Biology : If you're sick with the flu, eg, you don't really feel like doing anything although you are capable of doing so. That's same in depression - your brain mechanism for attention is ok, but your depression makes you sick, so you lose concentration. In adhd, you can't concentrate for various neurologic reasons, even if you wanted to.

Timing: In adhd, concentration problems are all the time in multiple situations. In depression, concentration problems occur only during episodes of depression. Remember, depression is episodic and adhd is all the time.

The depression.: Although add patients certainly can become depressed, the lack of ability to focus was present before the depression, while a depressed person had normal concentration before the depression hit.