I don't believe that the AD&D system of rules takes into consideration the effects of emotions and character's fighting styles into the combat methods. I have developed the following additional rules for such adjustments:

Concentrated Attack
A character may attempt to focus all of their efforts into finding a weakness in the enemy's defenses or simply pour on the pressure and concentrate on attacking an opponent. A character may choose to gain a +1 to Hit for every +1 to their AC (limit of +4 to hit). By focusing on attacking an opponent they are neglecting their own defenses.

Maintain Defense
A character may also attempt to focus on parrying the enemy's attacks or dodge blows as much as possible. However, by focusing on defending themselves they suffer a penalty to attack their opponent. A character may gain a -1 to their AC for every -1 to hit (limit of -4 to AC).

There are times that a PC may become filled with rage or other emotions and gain bonuses "unwillingly". I feel that the GM can enforce certain penalties and bonuses as the situation calls for them. If a Gm makes a ruling then the above rules are ignored and the temporary ruling is enforced. For instance if a character just saw a loved one killed in front of them they may go into a fit of rage and use everything in their power to kill an enemy. The GM may rule that the PC may get a +4 to hit the opponent, but suffers a -4 to their AC. The PC no longer cares what happens to them only that the one who killed their loved one pays for their actions.
In order to keep this from getting out of control a Gm must limit the number of rulings, the PC should play their character as they see fit. If the PC has a legitimate argument let it go. If it is questionable, make the PC roll a save vs. Paralyzation. If the PC fails, the Gm's ruling stand. If the roll succeeds the PC's choice stands.