Hockenbury Discovering Psychology 5th txtbk

Schizophrenia571and Stelazine, reduce or block dopamine activity in the brain. These drugs reduceschizophrenic symptoms, especially positive symptoms, in many people. Second,drugs that enhance dopamine activity in the brain, such as amphetamines and cocaine,can produce schizophrenia-like symptoms in normal adults or increase symptomsin people who already have schizophrenia.However, there is also evidence that contradicts the dopamine hypothesis. Forexample, not all individuals who have schizophrenia experience a reduction ofsymptoms in response to the antipsychotic drugs that reduce dopamine activityin the brain. And for many patients, these drugs reduce some but not all schizophrenicsymptoms. One new theory is that some parts of the brain, such as thelimbic system, may have too much dopamine, while other parts of the brain, suchas the cortex, may have too little dopamine (Combs & Mueser, 2007). Thus, theconnection between dopamine and schizophrenia symptoms remains unclear.Psychological FactorsUnhealthy FamiliesResearchers have investigated such factors as dysfunctional parenting, disturbedfamily communication styles, and critical or guilt-inducing parental styles as possiblecontributors to schizophrenia (Johnson & others, 2001). However, no single psychologicalfactor seems to emerge consistently as causing schizophrenia. Rather, itseems that those who are genetically predisposed to develop schizophrenia may bemore vulnerable to the effects of disturbed family environments (Tienari &Wahlberg, 2008).Strong support for this view comes from a landmark study conducted by Finnishpsychiatrist Pekka Tienari and his colleagues (1987, 1994). In the Finnish AdoptiveFamily Study of Schizophrenia, researchers followed about 150 adopted individualswhose biological mothers had schizophrenia. As part of their study, the researchersassessed the adoptive family’s degree of psychological adjustment,including the mental health of the adoptive parents. The study also included a controlgroup of about 180 adopted individuals whose biological mothers did not haveschizophrenia.Tienari and his colleagues (1994, 2006; Wynne & others, 2006) found thatadopted children with a schizophrenic biological mother had a much higher rate ofschizophrenia than did the children in the control group. However, this was trueonly when the children were raised in a psychologically disturbed adoptive home. Asyou can see in Figure 13.7, when children with a genetic background of schizophreniawere raised in a psychologically healthy adoptive family, they were no more likelythan the control-group children to develop schizophrenia.Percentage showing signsof serious mental disorder8070605040302010Adoptees whosebiological mothershad schizophreniaControl-group adopteeswith no genetic historyof schizophreniaRaised in psychologicallyhealthy adoptive familyenvironmentRaised in psychologicallydisturbed adoptive familyenvironmentFigure 13.7 The FinnishAdoptive Family Study ofSchizophrenia In the FinnishAdoptive Family Study, psychiatristPekka Tienari and his colleagues(1994, 2006) trackedthe mental health of twogroups of adopted individuals:one group with biologicalmothers who had schizophreniaand a control group whosebiological mothers did not haveschizophrenia. This graphshows the strong influence ofthe adoptive family environmenton the development ofserious mental disorders.