Chapter 16 - schizophrenia and the affective disorders had severe schizophrenia. required constant supervision. Schizophrenics have great difficulty arranging their thoughts logically and sorting out plausible conclusions from absurd ones. In conversation they jump from one topic to another as new associations come up. 2. followed by cognitive symptoms: positive symptoms follow years later. The search for abnormalities in dopamine transmission in the brains of schizophrenic. Consequences of long-term drug treatment of schizophrenia until recently the medication caused at least some symptoms resembling those of. Possible causes of brain abnormalities schizophrenia is caused by an interaction between genetic and environmental factors. 40s) underweight women are more likely to give birth to babies who later develop schizophrenia and that low birth-weight babies have a higher incidence of schizophrenia. If decreased activity of nmda receptors in the prefrontal cortex causes the negative and cognitive symptoms of schizophrenia, then we might expect drugs that act as.