Is depression a kind of allergic reaction?

Disturbed thinking and mood change due to varied reasons in suppressed circumstances may end up with depression.  The external influence (behavior of other persons) can be termed  as allergic reaction, or certain general or personal incidents may also be a cause and can be included in the allergic category.

Waiting for more answer and would like to follow.

Yes depression is a kind of allergic reaction which has some genetic roots and stimulated if couppled with some 

 harsh or tragic  factors 

I don't think so... All is possible to control

I'm not really sure. Those who suffer from depression have their normal lives interrupted by symptoms such as persistent sad thoughts, and inability to feel pleasure.

Yes, it is linked with the allergies but as per the management point of view most of the time resistance to the change and new methodology brings depression in the employee. Human mind some time do not accept directly the changes and requires stages of learning, acceptance and implementing. Depression causes a number of other problems such as increased heart rate, blood pressure, sugar. One must not take everything on head. Work should be left at office and mind should be sent for relaxation at home. 

I think we should leave this to the scientists and doctors for their training and knowledge, this is too deep a question for any standard manger to answer. I have known many who have suffered including close family members but I am not qualified to answer, mine would be to self opinionated without knowing the facts

allergy may be one of cause of depression ....

AM ALWAYS READY TO TAKE NEW RESEARCH ............................   DEPRESSION IS AS OLD AS WE HUMANS ARE ................... LETS SEE WHAT NEXT SCIENTIST SAY ABOUT THIS ILLNESS ?

Nobody is sure what causes depression. Experts from that field says depression is caused by a combination of factors such as the person's genes, their bio-chemical environment, personal experience and psychological factors. 

Yes It Is:

You may be surprised to find that your allergies and depression have a direct relationship. Yes, research has shown that some allergies can cause depression. In fact, in one study,70 percent of patients with depression had a history of allergies!

Over time your allergies can destroy your immune system and prevent your body from repairing itself. This is often when depression sets in. But, the good news is that when an allergy is discovered, depression can often lift away.

Although I personally don't believe so, but there are many scientists who believe in that. George Slavich, a clinical psychologist at the University of California in Los Angeles, has spent years studying depression, and has come to the conclusion that it has as much to do with the body as the mind. “I don’t even talk about it as a psychiatric condition any more,” he says. “It does involve psychology, but it also involves equal parts of biology and physical health.”

They say: everyone feels miserable when they are ill. That feeling of being too tired, bored and fed up to move off the sofa and get on with life is known among psychologists as sickness behavior. It happens for a good reason, helping us avoid doing more damage or spreading an infection any further.

It also looks a lot like depression. So if people with depression show classic sickness behavior and sick people feel a lot like people with depression – might there be a common cause that accounts for both?

The answer to that seems to be yes, and the best candidate so far is inflammation – a part of the immune system that acts as a burglar alarm to close wounds and call other parts of the immune system into action. A family of proteins called cytokines sets off inflammation in the body, and switches the brain into sickness mode.