You've decided to carry a handgun for self-defense. Your local government has issued you a license to do so and you have decided to exercise your right as a free citizen. You may think you will probably never need your gun to defend yourself. We all hope that is true. But if we felt that the possibility of a violent attack simply couldn't happen, we wouldn't bother with carrying a gun at all--because it is a bother! Carrying a gun is like having car insurance. You pray never to experience a serious accident, but you also keep your car insurance paid up at all times...because you never know. You may be an excellent driver, cautious, defensive, always watching the road. But you keep your insurance paid up anyway. Sure, it's the law, but if you are a responsible citizen you don't have car insurance because it's the law, you have it because you never know when you may need it. The devastation to your finances and your family should you be the victim of a large judgment without having any insurance would be horrendous.
Carrying a gun is much the same. You will probably never need it, but if you do ever need it and don't have it, you'll rue the day--and that is an understatement of epic proportions. To that end, having a gun is obviously the first requirement of self-defense. If you are serious about this then you will have that gun with you whenever possible and wherever legal. If you are clairvoyant and can tell when a gun will or won't be necessary, you don't need to carry--you don't need a gun at all because you can see the future and avoid trouble. But for those of us who are not clairvoyant, carrying everywhere possible is common sense. A gun is only useful if it is on our person. It is not useful at home on our dresser or in the gun safe while we are out. It is not useful in the car when we are not in the car. The gun will do nothing to protect you if you do not have the gun with you.
Still, just having a gun is not enough. You need a gun you can shoot, and shoot well. Studies of police shootings have shown that we undergo physical changes when confronted with a life or death experience. One aspect that this includes is the deterioration of fine motor skills. Another is that our brain automatically concentrates on the danger at hand, and the routine act of drawing our gun and shooting it will be subjugated. I think it is just common sense to realize that these things suggest a couple of realities. First, we should be well-practiced with our chosen self-defense handgun, because we won't be able to think about the routine physical moves involved in using it--if it isn't smooth and natural to us from repeated practice, it won't be smooth and natural when we need it. Then too, if we carry a small firearm that is difficult to shoot well due either to its small size, heavy recoil, or both, we are not likely to do well with it when we need it. If it is hard to shoot or uncomfortable to shoot, how much are you going to practice with it? And if you don't practice with it, you are going to do poorly with it when you really need it.
For those reasons I do not recommend choosing a carry gun based on size and weight. Unfortunately, that is exactly what most folks new to concealed carry will do!
I understand the desire to simply add a gun to your wardrobe, as it were, without any discomfort. That is why many folks choose something light and small. You know better. Light and small means a gun that carries comfortably but which is difficult to shoot, and perhaps even ineffective. Carrying a decent firearm usually means changes in your mode of dress. Simply putting a little gun in your pocket or purse is not good enough--not if you are serious about having a gun with which you can reasonably expect to defend yourself. Ideally you should have a handgun large enough to handle easily, that shoots a cartridge capable of delivering a decisive blow that will stop an attacker from doing you or your loved ones any (more) harm.
Pocket guns don't meet that criteria. They are too small to handle recoil well, and if they do handle recoil they are probably underpowered, chambered for .380 or worse: .32ACP, .25ACP or .22LR. These calibers kill people, but they rarely stop an attacker in his tracks. As a trained possessor of a concealed carry license, you know that killing someone is not our goal--stopping his attack is.
Pocket guns usually have very small sights and have poor accuracy out beyond handshaking range. While many gunfights are close-range affairs, you are betting your life on that average holding true for you. If you are involved in a shooting you've already beat the odds, do you want to gamble on the rest of it?
The ideal self-defense handgun for concealed carry is one that is chambered for .38 Special, 9mm, or better. It should have sights that are bold enough to pick up quickly. It should be comfortable to shoot, both in handling and the recoil of the gun. It should be something you enjoy shooting enough to want to go to the range weekly or at least a couple times per month. From there, the sky is the limit, and beyond the realm of this short article.
In the end you must decide how serious you are about self-defense with a handgun. Don't choose to carry a gun on a lark. Just owning a violin or having it handy doesn't mean you are a violinist. Just having a handgun--just any handgun--doesn't make you a trained shooter capable of self-defense.