Digestion problem. Please help.

My dad is under treatment of anxiety and depression, insomnia from 2005 till now.  He had stopped his medication in 2008 and 2011 for 1 month in each year due to some family issues.and had symptoms of depression insomnia again.then after taking the medicine he feels good. Also he had continued to take Norval 10 for last 2years without revisiting the doctor (psychiatrist). Now doctor told him to stop the Norval and take quitipin.but after 8 days he had nausea, vomiting, sleeping problem, constipation.and then doctor told him to stop quitipin and gave him zozert. Then also he had same symptoms..so doctor stopped zozert and gave him clofranil 10 ( he had this from 2005) and zapis 0.25 & 0.75. then also vomiting reoccur frequently. So he went to NIMHANS and the gave him nigopram 10 ,clonazep 0.25 & 0.5 and told to stop clofranil by lowering the dose. He was fine for 1 week. But again he had indigestion, vomiting, motion problem.we don't understand the reason for this symptoms. Please help.