The strength and the position of the Moon in a horoscope shows one's ability to manage the affairs of the mind. If the Moon is strong, the person will be able to absorb the emotional and psychological challenges and lead a healthy, happy life. However, if the Moon is afflicted by negative planets, one may experience varying degrees of mental instability. A strong, well-positioned moon, with only a favorable Jupiter's influence shows a balanced mind that allows the person to lead a happy satisfied life. After all, a balanced mind is one of the biggest blessings in life.
I have seen the horoscopes of multiple people with drug addiction. In all of them, Moon is with Rahu. Rahu is a shadowy planet and it confuses the mind. Rahu is called the South Node in western astrology. It makes the person go after illusions and believes in short term pleasure vs long term goodness. Unless positively influenced by Jupiter, people with Moon-Rahu combination could sway from the path of truth. If Moon Rahu combination is influenced by Saturn, it could make a person lunatic unless there are other compensating factors in the horoscope. Mars influencing a Moon-Rahu combination can make one do violent crimes. If Moon-Rahu combination is in a powerful position (like the house of power), one will be able to influence others to follow them. People who are cult leaders typically have this combination.
Sometimes the influence of Rahu on Moon can create health challenges that are of psychosomatic origin. Rahu indicates secrets and the diseases caused by Rahu's influence are often difficult to diagnose unless they reach later stages. People with Moon-Rahu combinations are advised to manage their minds early in their lives through meditation, yoga and other methods.
By understanding the position of Moon in your horoscope, you can better manage your mind. There are various remedies and precautions that you can take to stay away from potential troubles. Astrology doesn't say things will happen for sure, but it shows the direction in which things could go if you don't act on them.