Addiction to sweet and soft drinks.

My housewife is been treated for last 12 years for post parttrum schizoid/ bipolar disorder/ depression/ anxiety. Recent issue that she does not like house work and like fast food,snacks, softdrinks,ice-cream and does not like normal food. Her weight is 87kg now.her current doctor has put her on lithium 800 mg daily for last 4 months.does this happen due to any side effects of medicine she has been taking for last 12 years. She keeps gossiping over phone for hours on various irrelvent points and wastes her time . She sleeps sometime for 12 hours in day.she says I am not interested to do sansaar and does not take care of any housework. We have 12 yr daughter. Whatever she like she does on own,but other daily  tasks have to be told to her then only she performs. It is like she has become dependent on other members. She will fast but not eat normal food.