Neuromodulation of Motivation and Reward Oscillations

Inclusion Criteria (General):

* Aged between 18 - 55 years old.
* Able to provide informed consent
* Have normal to corrected vision
* Willing to comply with all study procedures and be available for the duration of the study
* Speak and understand English.
* Negative THC saliva test and alcohol breathalyzer at all lab visits.
* Negative UTOX for any substance other than THC.

Exclusion Criteria (General):

* Mania history (Bipolar I, or current mania).
* Psychosis history.
* Current suicide intent (score \>4 on C-SRSS, or intent \>0 on SRA)
* Current moderate-to-severe SUD or AUD (Except CUD and nicotine for NEMO-CUD).
* Current pregnancy.
* Seizure, neurological conditions, or brain surgery history.
* Implanted medical devices (e.g., cochlear implants, cardiac pacemakers).
* Change in psychotropic medication in the past 3 months (i.e., medication needs to be stable for 12 weeks).
* Use of seizure threshold lowering medication (e.g., Stimulants, Benzos, SNRIs, Antipsychotics \[Adderall, Vyvanse, Xanax, Wellbutrin, Cymbalta, Lithium\] - SSRIs not exclusionary).

Specific CUD Inclusion:

* Avg. 6+ cannabis use days per week over the past 3-months, and 24+ cannabis use days in the past 30 days.
* Primary delta-9 or THC-A cannabis flower or vape concentrate user.
* Current moderate-to-severe CUD (4+ criteria in the past year, at least one criterion other than craving must be met in the past three months).
* Cannabis is the primary substance of use (Nicotine dependence is allowable)
* Not currently receiving treatment for cannabis, planning to immediately quit or reduce use.
* Lifetime history of MDE/PDD must have lifetime anhedonia symptom and/or heavy cannabis user (3+ sessions daily for at least past year including the past 3-months and past 30 days).

Specific MDD Inclusion:

* Current MDE diagnosis.
* No lifetime history of severe SUD.
* No current moderate-to-severe SUD.
* 100% of NEMO-MDD participants elevated anhedonia on TEPS-C (i.e., 32 or lower on TEPS-C subscale).

Specific Control Inclusion:

* No current or historical psychiatric diagnosis.