23 yo pt has lack of motivation and difficulty with speech for 6 mos. He is started on an atypical antipsychotic and gets better. Which of the pt's sx are negative and which are positive sx? Do atypical antipsychotics primarily address the neg or pos sx? How does the mechanism of action of typical antipsychotics differ from that of atypical antipsychotics?
positive symptoms: delusions, hallucinations, disorganized speech, disorganized/catatonic behavior; negative symptoms: flat affect, social withdrawal, lack of motivation, lack of speech or thought. Typical antipsychotics (haloperidol, fluphenazine, etc.) are mainly used for positive symptoms and work by blocking dopamine D2 rec (inc cAMP conc). Atypical antipsych (Olanzapine, clozapine, quetiapine, risperidone, aripiprazole, ziprasidone) used for both pos and neg symptoms, but mechanism is not understood - effects on 5-HT2, dopamine, alpha, and H1 rec