Hello bzm,
I'm not a doctor, and I don't treat or diagnosis conditions, however, I can tell you a couple of things about taking meds for schizophrenia.
The course of treatment with an anti-psychotic is usually life-long, though the actual dose could change over the years based on a number of things, such as how your friend reacts to a particular med, what the maintenance dose of that medication is, and which exact dose provides maximum symptom relief for you friend in his individual case.
Also 25 mg of Risperdal Consta may seem like a lot, but each drug has different dosing strengths and is not to be compared with, say a 5 mg dose of Zxprexa or a 300 mg dose of Seroquel, for example.
The main thing to remember is that these medications work to halt or diminish the symptoms of schizophrenia, and provide a better quality of life than if the person with a diagnosis refuses treatment and goes without meds.
The majority of people with schizophrenia who discontinue their meds, relapse, and with each relapse, it's harder to bounce back.
So I wouldn't be concerned too much with the fact that your friend takes an anti-psychotic, and I wouldn't be concerned about the dose.
If it turns out the Risperdal Consta isn't effective at relieving her symptoms, she should work with her psychiatrist to find the drug or combination of drugs that does do the trick.
Best regards,
Chri