Amphetamine based stimulants (Ritalin, Adderall, dextroamphetamine, ephedrine, pseudoephedrine) do make you more interested in life and may increase interest in sex, but they will most likely impair erection at effective doses by constricting blood vessels.
They also constrict some muscles in the bladder/urethra, so they may lead to semen emission without strong ejaculation contractions or orgasm, or premature ejaculation, or burning while peeing (at high doses), or not being able to pee for some time if you overdose.
