In ECT, right unilateral lead placement may minimize cognitive side effects compared to bifrontal, left anterior right temporal, or bitemporal lead placements

Older adults generally have higher medical comorbidity due to medical complexity and are, therefore, at higher risk for polypharmacy. Treatment of bipolar disorder (depression, mania, mixed episodes) with ECT may allow for a reduction in polypharmacy to achieve remission, thus lowering the risk of drug–drug interactions.

Older adults with depression complicated by catatonic and psychotic features generally have better response rates to ECT than those without psychosis or catatonia.

Older age is generally a positive predictor of ECT response.

ECT has demonstrated efficacy in treating unipolar and bipolar depression.

Acute mania, acute depression, and mixed episodes in bipolar illness can be effectively treated with ECT.

TMS requires daily sessions for at least four weeks to demonstrate antidepressant effects.

While studies are limited, available data show that rTMS improves depressive symptoms in adult-aged bipolar patients. More data are needed to support its use in older adults with bipolar disorder.

Due to the invasiveness, cost, and complexity of DBS, more studies are needed before this experimental therapy becomes a clinical option outside of very specific trials.

In Parkinson’s disease, DBS has reportedly shown the potential of inducing mania when targeting the subthalamic nucleus.

As seen in this chapter’s clinical vignette, DBS is a therapy that is reserved for patients who have failed less invasive neuromodulation treatments.

MST combines elements of ECT and TMS, producing fewer cognitive side effects compared to RUL ECT.

MST allows for a focal seizure restricted to the superficial cortex.

Available literature indicates that MST is a promising option in treating bipolar depression.

tDCS is generally inexpensive and has the potential of being administered in non-specialized clinical environments.

tDCS has demonstrated efficacy in treating bipolar depressed patients in small studies.

FEAST initiates focal seizures in the prefrontal cortex with subsequent generalization and may be a neuromodulation therapy that produces fewer cognitive side effects compared to ECT.

FEAST has shown significant antidepressant effects in both unipolar and bipolar depressed patients with no current data on treatment-emergent mania.

Ketamine is an NMDA receptor antagonist, with significant transient antidepressant effects when administered intranasal or intravenously.

Ketamine can prolong seizure time in ECT when used as an anesthetic agent, with potential independent antidepressant effects and theoretically less cognitive adverse effects. Large double-blind randomized clinical trials are needed to investigate these findings further.

Ketamine has been found to possess rapid antisuicidal effects within 60 min in patients with bipolar depression.