Allopurinol
A well tolerated option for mania, but third-line due to few trials.
Buspirone
Treats anxiety (GAD). Augments in depression but only if anxious. Also improves sexual dysf, bruxism, irritability, PMDD
Dextromethorphan
Think of it as low-potency ketamine. Rapid acting as Auvelity in depression, or as monotherapy (3rd line) in bipolar depression. Abuse potential.
Lithium
Best long-term outcomes in bipolar (I or II) and recurrent depression. Prevents suicide. Treats mania, bp-depression and augments antidepressants.
Celecoxib
[Celebrex] NSAID for treatment-resistant unipolar and bipolar depression [3], works better if inflammation [2]. Well-tolerated short term, but long-term risks.
Baclofen
Muscle relaxant can be very effective for alcohol [2] but has small misuse potential. Also binge eating [3].
Acamprosate
[Campral] Well tolerated but low efficacy for alcohol use disorder. May make WD symptoms less aversive.
Disulfiram
(Antabuse) Treats alcoholism by raising the chemical responsible for hangovers. Very effective if patient takes it.
Methylphenidate
First-line stimulant (more neuroprotective and safer for mental health than amphetamine). May help apathy in old age but not for depression.