According to the Focalin XR literature, (and I'm not sure if you're on the XR, but I checked the regular Focalin and it says the same)
The maximum recommended dose is 20 mg/day for pediatric and adult patients.
I can't imagine that a seven year old, unless he weighs as much as an adult, should be on that dosage. I'm not a doctor, but I would really be questioning this.
And the zoloft, this is taken from the literature I found online
Dosage for Pediatric Population (Children and Adolescents)
Obsessive-Compulsive DisorderZOLOFT treatment should be initiated with a dose of 25 mg once daily in children (ages 6-12 and at a dose of 50 mg once daily in adolescents (ages 13-17).
While a relationship between dose and effect has not been established for Obsessive Compulsive Disorder (OCD), patients were dosed in a range of 25-200 mg/day in the clinical trials demonstrating the effectiveness of
ZOLOFT for pediatric patients (6-17 years) with Obsessive Compulsive Disorder (OCD).
Patients not responding to an initial dose of 25 or 50 mg/day may benefit from dose increases up to a maximum of 200 mg/day. For
children with Obsessive Compulsive Disorder (OCD), their generally lower body weights compared to adults should be taken into consideration in advancing the dose, in order to avoid excess dosing.
Given the 24 hour elimination half-life of ZOLOFT, dose changes should not occur at intervals of less than 1 week.
Additionally, since Zoloft is an SSRI, taking both the focalin and zoloft together can increase the plasma concentration of the zoloft. They are not contraindicated, meaning they shouldn't be taken together, but they do say in the literature that caution is advised because of the increase to the concentration of zoloft.
My take on this--and remember, you get what you pay for
is that the medications may be too high and his aggressiveness could actually be a byproduct of the high dose medications--possibly inducing mania, which in kids can just present as irritability, and a lot of it. Also would explain his hearing voices.
I would make a call to the pediatrician tomorrow to find out more information and see what you need to do as far as weaning him off his medications if those levels are too high. DO NOT DO IT WITHOUT CONSULTING A DR--zoloft needs to be decreased in increments over weeks. Let the MD tell you how much and for how long.
If the pediatrician tells you what I think he/she will, then I would find a new psychiatrist.