The Salvadoran man who drifted to a Marshall Islands atoll last month is still in hospital as doctors say he requires antidepressants and anxiety medication.
Jose Salvador Alvarenga is reportedly afraid of the sea, a symptom medics earlier linked with possible post-traumatic stress disorder.
Doctors say his family will be asked to keep him away from the water once he is released from hospital in El Salvador.
Doctors have not decided when he will be released, but his attending physician says Mr Alvarenga will need outpatient psychiatric care for at least six months.
Mr Alvarenga gave several interviews after he washed ashore in the Marshall Islands, telling reporters he had survived in a fibreglass boat for more than a year after setting off from Mexico in late 2012.
The fisherman says he endured the 12,500-kilometre trip by eating raw fish and bird flesh and drinking turtle blood and his own urine.