There are apparently [at least] 2 approaches to going to judgment or "din" during Adar
1. We have a "spiritual" upper hand at work. Thus there are forces pulling strings on our behalf as in "Days of Yore"
2. We are joyous. Thus we are PSYCHED UP by being in a ebullient mood. This mindset is geared to make us successful in a psychological way due to natural forces such as "charisma" and positive attitude.
The Kitzur SA seems to indicate the 2nd derech in his terse summation in 141:1
Note, too, that the converse should be true for Mishenichnas Av. There in KSA 122:7 we apparently see reason #1 "d'rei'a mazleih"
However, this perhaps CAN be understood as a term [bittuy] for our mental melancholia and not something supernatural at all
I'd like to say the following
The moods of Adar and Av seem to be not only descriptive, but also prescriptive.
Therefore going to DIN should reflect those moods. E.G. Were we to go to Din during Av and be in an optimistic mood, there would be something missing from our "avodah.". Similarly, we should dispel any internal pessimism during Adar.