Antipsychotic drugs negative symptoms

Schizoid Personaiity Disorder (SPD). Again, there is very little research to guide in the selection of medications to treat the schizoid patient. If we conceptualize the symptoms of SPD as most resembling the negative symptoms of schizophrenia, the choice of agents would tend to favor the atypical antipsychotic drugs as opposed to the older typical antipsychotics. Consequently, we also recommend low doses of an atypical antipsychotic as a first-line treatment for SPD. 

Efficacy in short-term treatment. From studies in adult schizophrenia, it is evident that clozapine treatment has at least the same or superior antipsychotic effect, compared to typical antipsychotics. In some studies, clozapine was superior with regard to symptom reduction in severe and acute schizophrenic patients. As the guidelines do not allow the use of clozapine as a first-choice drug, most patients have been treated before with at least two atypical or typical antipsychotics. Only one controlled trial has assessed the efficacy of clozapine in child and adolescent psychiatry. In this study (Kumra et ah, 1996), clozapine was found to be superior to haloperidol in all measures of psychosis, and showed a striking superiority for both positive and negative symptoms. 

For approximately 70% of patients with schizophrenia, and probably for a similar proportion of patients with bipolar disorder with psychotic features, typical and atypical antipsychotic drugs are of equal efficacy for treating positive symptoms. However, the evidence favors atypical drugs for benefit for negative symptoms and cognition, for diminished risk of tardivedyskinesia and other forms of EPS, and for lesser increases in prolactin levels. 

FIGURE 10—11. Several different causes of dopamine deficiency may result in negative and cognitive symptoms. In schizophrenia itself, there may be a primary dopamine (DA) deficiency or a DA deficiency secondary to blockade of postsynaptic D2 dopamine receptor by an antipsychotic drug. If serotonin is hyperactive, this may also cause a relative DA deficiency by inhibiting DA release. Either primary or secondary DA deficiency in this pathway may cause cognitive blunting, social isolation, indifference, apathy, and anhedonia. 

From a clinical perspective, an atypical antipsychotic, however, is defined in part by the clinical properties that distinguish such drugs from conventional antipsychotics, namely, low extrapyramidal symptoms and efficacy for negative symptoms. By understanding the difference between blocking dopamine D2 receptors alone... 

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