Final answer:
Treating depression in a lung cancer patient can improve their quality of life but does not cure the cancer nor directly increase the chances of survival.
Step-by-step explanation:
Treating depression in a patient who has lung cancer can potentially improve her quality of life. While depression treatment does not cure cancer, it can provide significant benefits by helping alleviate depressive symptoms, thereby potentially enhancing the individual's overall well-being and ability to cope with their cancer diagnosis. It is important to note, however, that such treatment does not increase the chances of survival directly nor does it increase the level of depression.