In order to clarify this problem , we conducted three studies to identify the biochemical background of cognitive-behavioural psychotherapy ( CBT ) , individual psychology brief psychotherapy ( IBPP ) , and psychotherapy-pharmacotherapy with CBT + olanzapine in anorexics ( AN ) and bulimics ( BN ) by measuring the levels of plasma homovanillic acid ( HVA ) for dopamine secretion , plasma @-methoxy-@-hydroxy-phenylglycol ( MHPG ) for noradrenalin secretion , and platelet -LSB- @H -RSB- - Paroxetin-binding Bmax and Kd for serotonin transporter function .