STimulation to Improve Auditory haLLucinations

The investigator's primary objective is to conduct a pilot clinical trial to establish the
feasibility and to collect first effectiveness data for the use of transcranial alternating
current stimulation (tACS) to re-normalize pathological alpha oscillations in dorso-lateral
prefrontal cortex (dl-PFC) of patients with schizophrenia or schizoaffective disorder by
comparing Auditory Hallucination Rating Scale (AHRS) scores immediately before the first
stimulation session and immediately after the last stimulation session. As a secondary
objective the investigators will assess the differential clinical effects of sham, 10 Hz and
2 mA transcranial direct current stimulation (tDCS) on electroencephalogram (EEG) measures of
alpha oscillations.

Inclusion Criteria:

- DSM-IV diagnosis of schizophrenia, any subtype, or schizoaffective disorder, with
refractory auditory hallucinations. Duration of illness >1 year

- 18-70 years old

- Clinically stable for at least 12 weeks, i.e. not requiring hospitalization or a
change in level of care

- On current antipsychotic doses for at least 4 weeks

- Stable auditory hallucinations as demonstrated by having less than or equal to 20%
change in AHRS scores across a 2 week interval during the screening period.

- Capacity to understand all relevant risks and potential benefits of the study and to
provide written informed consent, OR has a legal guardian who can provide informed
consent on the patient's behalf with the patient providing written assent to
participate.

Exclusion Criteria:

- DSM-IV diagnosis of alcohol of substance abuse (other than nicotine) within the last
month or a DSM-IV diagnosis of alcohol or substance dependence (other than nicotine)
within the last 6 months

- Medical or neurological illness (unstable cardiac disease, AIDS, malignancy, liver or
renal impairment) or treatment for a medical disorder that could interfere with study
participation

- History of traumatic brain injury that required subsequent cognitive rehabilitation,
or caused cognitive sequelae

- Prior brain surgery

- Any brain devices/implants, including cochlear implants and aneurysm clips

- Co-morbid neurological condition (e.g. seizure disorder, brain tumor)

- Non English speakers

- Female participants who are pregnant, nursing, or unwilling to use an adequate method
of contraception during study participation for those of childbearing potential

- Positive urine test for cannabis, cocaine, amphetamine, barbiturates, benzodiazepines,
opiates