Trial of Bilateral tDCS for Depression

Inclusion Criteria:

1. Participant meets criteria for a DSM-IV Major Depressive episode.
2. MADRS score of 20 or more.

Exclusion Criteria:

1. Diagnosis (as defined by DSM-IV) of: any psychotic disorder (lifetime); eating disorder (current or within the past year); obsessive compulsive disorder (lifetime); post-traumatic stress disorder (current or within the past year); mental retardation.
2. History of drug or alcohol abuse or dependence (as per DSM-IV criteria) within the last 3 months (except nicotine and caffeine).
3. Inadequate response to ECT in the current episode of depression.
4. Participant is on regular benzodiazepine medication which is not clinically appropriate to discontinue.
5. Participant requires a rapid clinical response due to inanition, psychosis or high suicide risk.
6. Neurological disorder or insult, e.g., recent stroke (CVA), which places participant at risk of seizure or neuronal damage with tDCS.
7. Participant has metal in the cranium, skull defects, or skin lesions on scalp (cuts, abrasions, rash) at proposed electrode sites.
8. Female participant who is pregnant, or of child-bearing age, sexually active and not using reliable contraception (urine test for pregnancy will be used).
9. Participants who are not fluent in English will not be included in the trial for safety reasons.