Okay, I'll simplify it
Antipsychotics - Drugs such as Haldol and Zyprexa, used to treat Psychosis, which is found in disorders such as Schizophrenia and Bipolar Disorder.
Antidepressants - Drugs such as Prozac and Effexor, used to treat depression.
Mood Stabilizers - Drugs such as Lithium and Carbagen, used to stabilize severe mood swings. Used to treat mood affective disorders.
Depressants - Drugs such as Benzodiazepines, used to treat anxiety and off-label off use of insomnia.
Stimulants - Drugs such as Ritalin. Used to treat mental health issues such as ADHD.
Off-label drugs - Some drugs that aren't manufactured necessarily for mental health problems, but can help control symptoms. Drugs such as Preglabin/Lyrica.