It is always difficult to provide a reliable diagnosis over the Internet. Knowing if your brother’s schizophrenia diagnosis is correct is especially difficult in this situation since he had been taking psychotropic medication on an irregular basis. It is unclear if that medication was contributing to his symptoms.
You also mentioned that he used alcohol and possibly drugs. The use of those substances can worsen the symptoms of any mental health disorder.
I’m not sure of your brother’s age.. Schizophrenia is rare before the age of 15. Generally, the age of onset for males is approximately 15 to 25. He may have had a negative reaction to a medication or to drug or alcohol use. There are some people who have one psychotic episode and never have another.
Alternatively, schizophrenia is a realistic possibility given his symptoms and the fact that he received his diagnosis during a recent hospital stay. Mental health professionals, who have had the opportunity to evaluate him, believe that he has schizophrenia. That lends credibility to the diagnosis.
The reality is that over time you will know if the diagnosis is correct. If he does have schizophrenia, there is hope. There are many effective treatments. It is not a “death sentence.” There are people with schizophrenia who live happy, productive lives. Following the treatment recommendations of his mental health clinicians will significantly increase the likelihood of recovery and stability.
As a family member it is important to support and love your brother. Love does not cure schizophrenia but those who have the disorder do best in stress-free, supportive living environments. Encourage him to follow his treatment recommendations. If you have additional questions, please do not hesitate to write again.