Antipsychotic drugs cognitive symptoms

In summary, antipsychotic drugs have a significant impact on the acute resolution and the maintenance of remission of symptoms of schizophrenia, enabling focus on rehabilitation efforts directed at residual cognitive, social, and occupational disabilities. The... 

The typical antipsychotic drugs, which for 50 years have been the mainstay of treatment of schizophrenia, as well as of psychosis that occurs secondary to bipolar disorder and major depressive disorder, affect primarily the positive symptoms[10]. The behavioral symptoms, such as agitation or profound withdrawal, that accompany psychosis, respond to the antipsychotic drugs within a period of hours to days after the initiation of treatment. The cognitive aspects of psychosis, such as the delusions and hallucinations, however, tend to resolve more slowly. In fact, for many patients the hallucinations and delusions may persist but lose their emotional salience and intrusiveness. The positive symptoms tend to wax and wane over time, are exacerbated by stress, and generally become less prominent as the patient becomes older. 

Nonpsychotic persons also experience impaired performance as judged by a number of psychomotor and psychometric tests. Psychotic individuals, however, may actually show improvement in their performance as the psychosis is alleviated. The ability of the atypical antipsychotic drugs to improve some domains of cognition in patients with schizophrenia and bipolar disorder is controversial. Some individuals experience marked improvement and for that reason, cognition should be assessed in all patients with schizophrenia and a trial of an atypical agent considered, even if positive symptoms are well controlled by typical agents. 

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. 

Cognitive Effiects. Along with the overt psychotic symptoms that characterize schizophrenia, deficits in cognitive function are commonly manifested by impairments in attention, information processing, and memory (14, 701-703). While antipsychotic drugs can ameliorate impaired attention and information processing, their effects on memory... 

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