1. It is not clear whether she recognizes that her water consumption is excessive or if she believes that it is good to drink that much water. What is her view of her water consumption? (The suggestions that follow are based on the assumption that she is not psychotic and that the problem turns out to have a lot in common with OCD and/or eating disorders).


2. If you haven't been doing so, it could be useful to have her record the amount of liquid she consumes on each occasion and also to record the situation, her mood, and her automatic thoughts. Graphing the amount of liquid consumed per day provides an easy way to track your progress, and an understanding to the situations, emotions, and thoughts which coincide with the desire to drink would be useful.


3. From the information you have presented so far, it sounds as though Exposure and Response Prevention is appropriate. If she continues to be unable or unwilling to do exposure sessions on her own or with the assistance of friends and family, you may need to do more frequent and/or more prolonged sessions with her. This probably will involve her needing to tolerate more intense anxiety, therefore it is important for her to understand and accept the idea that the way to overcome this problem is to face the situations which elicit her anxiety and/or the desire to drink but to refrain from drinking and tolerate the anxiety.


4. It sounds as though it will also be useful to help her challenge some of her automatic thoughts. With thoughts such as "If I don't drink I will die" and "I depend on water" I would first find out what she means. If she is thinking that she needs to consume large quantities of water in order to remain healthy, I would use guided discovery to challenge this view and help her reach more realistic conclusions about the level of fluid consumption needed for good health. I also would see if she understands the medical risks that this level of water consumption presents.
   With thoughts like "I feel better and stronger after I drink" I would help her test whether this is indeed true (possible by rating her mood before and after drinking), I would make sure she understands the value of tolerating anxiety rather than trying to avoid it, and I might help her find more adaptive ways of feeling healthy and strong.
   Throughout our work on the automatic thoughts, I would make it clear that "rational responses" may be helpful, but that ratonal responses alone will not alleviate her anxiety of eliminate her problem with excessive drinking. To be effective, the cognitive interventions must be paired with Exposure and Response Prevention.


5. It is important to understand her view regarding the consequences of limiting herself to ordinary levels of water consumption. She may have some idiosyncratic beliefs or fears that need to be addressed.

I hope these initial suggestions are useful. I'd encourage other readers to post their suggestions and I'd encourage you to post any further questions you have and to let us know how treatment progresses.