Charlie Sheen is “Charlie,” a successful therapist who thrives on the chaos in his life while still battling his own anger issues. Charlie’s colorful cast of patients includes his weekly regulars and the group of inmates he counsels pro bono at a state prison. His life is further complicated by his relationships with women, including his own therapist and best friend (Selma Blair), his ex- wife (Shawnee Smith) and his 13-year-old daughter (Daniela Bobadilla).

The new "evolved" Charlie has to deal with a ghost from his old carousing, baseball-playing days when a unattractive woman he slept with just to break a batting slump shows up as a new patient in group therapy.

Charlie challenges his group to do thirty-six hours of sleep deprivation therapy so that their "inhibitions come down and the truth comes out" - except the result turns out to be the exact opposite.

A long-standing rivalry over who's a better therapist leads to war when Kate steals Patrick, one of Charlie's group patients.

Charlie falls for Jen’s hot new business partner, Lori - played by Charlie's real-life ex, Denise Richards - only to find she thinks therapy is a scam.  In the therapy group, Patrick asks Charlie to counsel the angry ghost of his mother, who he believes is haunting his apartment.

Inflamed by Kate's comment that he's only "nouveau smart", Charlie starts covertly dating a brilliant coffee-shop barista.  The only problem is that the woman is turned on by sex where there's a chance of getting caught and she's Kate's patient.