It could be. All I can tell you is, if it bothers you, see a professional who can determine what it is and how best to treat it. Not being able to concentrate could also be ADD, and maybe a med for ADD would help more with that symptom. When my depression was at its worst, I could not concentrate on reading either, and that was really hard. Not only do I love to read, but I was a full-time student. I used SJW, and it helped with the depression, but didn't do anything for my concentration. I think that just took time. My sister (who is a psychiatrist) suggested trying Strattera for that, but I never did. There can often be a connection between diabetes, hypoglycemia, carbohydrate craving, and depression too I think, and also with circadian rhythm disorders. Your carbohydrate craving and sleeping during the day, being awake at night, suggests the possibility of a circadian rhythm disorder. Light therapy helps with that. It also runs in families.

We are able to detect chemical differences where there is depression, and medications that correct those imbalances do help, but it is impossible to say whether the chemical stuff is a cause or an effect of depression. Everything has more than just one factor involved, and the biological part is not the complete story. What is going on in your life contributes, as well as social support (or lack thereof). There are also psychological factors such as your thought patterns and how you deal with stress. For this reason, medications don't cure depression. I really feel that therapy is also necessary. You can start with strategies for better concentration if that is your main concern.

Anti-depressants are not considered to be addictive, although most of them do have withdrawal symptoms when you stop taking them, and your brain has to re-adapt to produce appropriate amounts of the neurotransmitters affected.

I wish you luck, and hope that some of this helps you!

<font color=orange>"Never forget: 2 + 2 = 5 for extremely large values of 2."</font color=orange>