One of the most destructive things that any marriage or relationship can possibly experience is paranoia. If your wife's insecurities are so strong that she routinely behaves in a paranoid and suspicious way toward you, it can lead to a lot of tension, doubt and resentment in your marriage. Try to reassure and help your wife to eliminate these negative and detrimental behavioral patterns -- for good.
Ask her to tell you how she feels. Encourage your wife to communicate to you all of her biggest woes and worries with regard to your relationship. Find out what she fears the most, whether it is you leaving her for another woman or even just your eye wandering. Listen actively and try to refrain from getting upset and judging her. Show patience and caring.
Reassure her. If your wife wants the comfort of hearing from you that there is absolutely nothing to worry about, provide it to her. If she vocalizes a worry about, for instance, your close friendship with a female co-worker, speak openly with her about it without getting defensive. Say, for example, "Laura and I are just really good friends. You can even stop by my office and see for yourself." The less open you are willing to be with her, the more suspicious and paranoid she may become.
Let her know all about what you do. Your wife's imagination may always be in overdrive because she simply doesn't know what is going on in your life. To assuage her concerns, keep her in the loop more. If you want to go out for dinner with your closest buddies until late at night, alert her to the fact so she doesn't sit up all night wondering and worrying about where you may be.
Spend more time with your wife. A little togetherness may go a long way in strengthening your marriage. Perhaps your wife is acting paranoid as a means to get attention from you. Maybe decreased communication and contact are causing her to feel a rift and as a result, act out toward you. Put time and effort in to enhance your marital bond, whether it is through regular "date" nights or nightly strolls together. When a spouse feels neglected and left out, it is not surprising for her to behave insecurely.
Appreciate your wife. If your wife feels unloved and like you do not care about her anymore, it may trigger feelings of paranoia. Take some time out of your day, every day, to let your wife know just how much she means to you. Compliment her looks or her sense of humor. Just a few kind words may make the world of difference in your wife's confidence and security within the relationship.
Show firmness. If your wife's paranoia and insecurity become out of hand, behave in a firm and assertive manner. If she asks you the same accusatory question repeatedly and shows no signs of letting up, tell her in a clear tone that you have already spoken to her about that topic and there is nothing more you can say. Either walk away from her temporarily or try to discuss something entirely different. Avoid enabling her behavior (and irrational criticisms of you) by knowing when to stop something.