tehran with approximately twelve million citizens is the largest city of iran , with most of its population being immigrants . this study was conducted from february 2010 to september 2011.the participants were defendants with a judicial order of evaluation for mental status and criminal responsibility . these participants were evaluated by two forensic psychiatrists with a doctoral - level education in psychiatry and an experience of twelve - month training in forensics while not being aware of the purpose of the study , using american psychiatric association 's diagnostic and statistical manual 4th edition text revised ( dsm - iv - tr ) criteria for mental disorders . malingerers were diagnosed according to misattribution of symptoms , unusual hallucinations , distortion of notifications , fictions of complaints , and exaggeration of their symptoms . subjects excluded from our study were those without definite diagnosis of at least one forensic psychiatrist , subjects with positive screening tests of alcohol and drug at the time of arrest , subjects with a history of previous imprisonment , illicit drug abuse , determined mental , neurological or psychiatric problems and those who received psychoactive medications . finally , forty five malingerers were included and assessed in another interview by the head of forensic psychiatry center . because of the legal order to evaluate mental status of the subjects and intentional faking symptoms to deceit forensic psychiatrists , informed consent was not obtained from the fakers taking part in our study . ethical approvals for this study were obtained from tehran university of medical sciences research ethics committee prior to the launch of the study . demographic variables were obtained from family reports ( if accessible ) and court reports about educational level , ancestry , marital status , and employment . symptoms were documented using an absolute list of 31 symptom presentation variables after a research pre - testing . the captions of manifestation used to construct the areas were ( 1 ) mood and affect , ( 2 ) thought content , ( 3 ) thought process , ( 4 ) perception , ( 5 ) cognitive function , and ( 6 ) behavioral disorder symptoms ( 14).motivations of malingering were assessed according to the court order ; and financial gain or relief from responsibility in a felony background was concluded.the categories of charged with felonies versus  not charged with misdemeanors were analyzed in 22 contingency tables with fisher 's exact test due to small numbers of the felonies . the level of statistical significance was set at p < 0.05 . tehran with approximately twelve million citizens is the largest city of iran , with most of its population being immigrants . this study was conducted from february 2010 to september 2011.the participants were defendants with a judicial order of evaluation for mental status and criminal responsibility . these participants were evaluated by two forensic psychiatrists with a doctoral - level education in psychiatry and an experience of twelve - month training in forensics while not being aware of the purpose of the study , using american psychiatric association 's diagnostic and statistical manual 4th edition text revised ( dsm - iv - tr ) criteria for mental disorders . malingerers were diagnosed according to misattribution of symptoms , unusual hallucinations , distortion of notifications , fictions of complaints , and exaggeration of their symptoms . subjects excluded from our study were those without definite diagnosis of at least one forensic psychiatrist , subjects with positive screening tests of alcohol and drug at the time of arrest , subjects with a history of previous imprisonment , illicit drug abuse , determined mental , neurological or psychiatric problems and those who received psychoactive medications . finally , forty five malingerers were included and assessed in another interview by the head of forensic psychiatry center . because of the legal order to evaluate mental status of the subjects and intentional faking symptoms to deceit forensic psychiatrists , informed consent was not obtained from the fakers taking part in our study . ethical approvals for this study were obtained from tehran university of medical sciences research ethics committee prior to the launch of the study . demographic variables were obtained from family reports ( if accessible ) and court reports about educational level , ancestry , marital status , and employment . symptoms were documented using an absolute list of 31 symptom presentation variables after a research pre - testing . the captions of manifestation used to construct the areas were ( 1 ) mood and affect , ( 2 ) thought content , ( 3 ) thought process , ( 4 ) perception , ( 5 ) cognitive function , and ( 6 ) behavioral disorder symptoms ( 14).motivations of malingering were assessed according to the court order ; and financial gain or relief from responsibility in a felony background was concluded.the categories of charged with felonies versus  not charged with misdemeanors were analyzed in 22 contingency tables with fisher 's exact test due to small numbers of the felonies . characteristics of the defendants and statistical results comprising the two groups are demonstrated in table 1 . no significant difference was observed between groups in sex , provenance , occupation and marital status , but the misdemeanor group was fairly less educated and contained proportionally more married urban subjects . the mean age of the 45 defendants was 40.31  15.12 years with the range of 19 to 76 years . participants charged with criminal accusation had significantly lower mean age than other non - criminal defendants . there were 44 immigrants ( 28.9% rural , 68.9% urban ) , and only one participant was citizen of tehran . twenty four had nine years of education or less , three had bachelor 's degree or higher . sixteen were single , of whom only one was divorced ; and 20 were unemployed . misdemeanors were comprised of one domestic disturbance , three illicit drug trafficking , four robberies , ten claims on insurance policies based on a traumatic event ( especially a minor head trauma ) , and 20 fraud and felonies including three sexual assaults and four violent offences and murders . background information of felony and misdemeanor groups symptoms were assessed in six significant domains ( 14 ) . follow - up studies incorporated fisher exact tests for each dependent variable reported in table 2 . a statistically significant increase in memory function problems was demonstrated in the misdemeanor group regardless of time period . n value and percentages do n't equal total of columns since some subjects had fake multiple symptoms . differences among the other 25 ( including seven subgroups ) and the six captions of variables were not statistically significant . table 3 demonstrates the concordant occurrence of feigned symptoms according to the denunciatory group of malingerers . concordant occurrence of the caption variables with regard to concordant occurrence of two symptom domains ( 14 ) , statistically significant associations were observed between the thought content and perceptual symptoms for felonies . misdemeanor cases had significant correlations between moods & affect and thought process symptoms , mood & affect and behavioral symptoms as well as cognitive function and behavioral symptoms . regarding the other symptoms in the present study , we analyzed the characteristics of the most relevant symptoms of malingering among the iranian population . in iran , no traditional use of tests as a part of a standard forensic psychiatric examination has been established ; furthermore , the validity and reliability of such tests are not studied for iranian population ; thus , there has been no indication of applying such tests . however , longitudinal assessments made by forensic psychiatry experts with appropriate information for determining the diagnosis can be applicable in most cases ( 15 ) . in this study , there were 45 participants with the diagnosis of malingering confirmed by two separate psychiatric interviews from february 2010 to september 2011 . the mean age of participants was 40.31  15.12 years which is higher than reported by american studies ( 1618 ) . in our study , we had no restrictions on major offenses , as investigation of more than a half of all cases was performed on fraud or plaintiffs who claimed psychotic problems to terminate financial contracts . the male to female ratio in our study was 41:4 , which reflects male predominance as female malingering of psychotic symptom is less common in our study group compared to other studies ( 17 , 18 ) . this could be explained by sample selection from inmates of province county jails in american studies compared with some subjects in our study who were referred for outpatient evaluation . on the other hand , none of the women in our study were involved in complex felonies or criminal offences ; and social rejection of psychotic patients , especially in iranian women , probably leads to avoid resorting simulations of mental disorders even in prisoners . a relatively low education level of 7.25 years was observed ; namely , in the seven criminal cases the education level was 10.8 years and in 38 misdemeanors , it was 6.6 years . in american malingerers who were criminal defendants referred for evaluation of competency to stand trial or criminal responsibility ( 12 ) , the mean level of education was 10.4 years which is similar to the seven criminal cases in our study . however , in another study carried out on adult inmates from maximum and minimum security jails in a rural southeastern county of the united states , malingerers had lower level of education compared to the genuine patients ( 18 ) . the employed to unemployed ratio in our study was 25:20 . considering that the unemployment rate in iran is about 11 percent , we could conclude that more unemployed individuals may be involved in criminal acts or attempt to commit fraud , and due to lack of adequate intelligence and genius , they often simulate psychotic symptoms poorly . the majority of faked psychiatric symptoms are more frequent in urban population , with a rural to urban ratio of 13:32 . this could be explained by less instability of social status in rural cases after immigration , probably because they are willing to do even hard jobs and live with fewer benefits . in comparison , in an american multi - center study examining base rates of malingering , differences were not significant in several locations ( 13 ) . typically , the clinical symptoms and signs obtained in the psychiatric interview should be congruent and lead to a significant diagnostic approach . for example , perceptual symptoms such as auditory hallucinations and some delusional thoughts usually indicate schizophrenic disorders . furthermore , mood symptoms , behavior disturbances and psychomotor activities are the most frequent symptoms in mood disorders . mood is a subjective symptom , but behavior disturbances or psychomotor activities are detected by psychiatrists during a psychiatric interview . a person with delusional disorder usually does not have a history of prominent auditory hallucination , and also , severe bizarre behaviors combined with depressed mood without other psychotic symptoms are rare , but faked symptoms do not usually introduce a known psychiatric diagnosis . for instance , a person may claim that he / she suffers from auditory hallucination but no abnormal behaviour may be observed . some malingerers show mood disorder symptoms but can not introduce congruent behaviour within psychiatric examination . the most common feigned psychotic symptoms in our participants were behavioral ( 77.8% of cases who charged with felonies or misdemeanors ) , mood & affect ( 68.9% ) , and cognitive function symptoms ( 60% ) . in another study focused on comparison of forensic and non - forensic malingerers , the most common symptoms feigned by forensic malingerers were medical syndromes or cognitive impairments ( 11 ) , while the most common deceitful symptoms in criminal defendants referred for pretrial and outpatient evaluation of competency to stand trial or criminal responsibility were perceptual and auditory hallucination , followed by behavioral symptoms in cornel and hawk study ( 1989 ) . as the role of a previous consort with other vicious people or prisoners and learning psychotic symptoms from video films is more prominent in foreign studies , defendants may be familiar with the symptoms of mental disorders ( 2 , 19 ) . however , in our study we excluded subjects with history of imprisonment , illicit drug abuse , determined mental , neurological or psychiatric problems to make a relatively pure sample of participants without psychotic symptoms . in our study , participants often used simple methods such as refusing to answer questions during interviews , having unusual or bizzare behavior , or claiming depression or memory loss . in the two of seven criminal cases , defendants claimed obsession and , at the same time , hallucination and pseudo hallucination . from 38 misdemeanors , 39.5% feigned mood & affect beside thought process disorder symptoms ; 55.2% feigned cognitive function and mimic behavioral disorder symptoms ; and 65.8% simulated mood & affect and behavioral disorder symptoms concurrently . the main restriction of this study was unavailability of standard tests to use in a control group . therefore , the conclusions may not apply to other situations such as a forensic hospital , where the array of patients may be different . in general , it seems that differences among presenting symptoms among different offenses may not be useful in detecting malingering . however , unusual dual symptom imitation may be useful , particularly when standard tests are not performed .
objectivein many jurisdictions , psychiatric problems are intended for commutation . 
 therefore , a forensic psychiatrist has an important role in detection of malingering . 
 while several studies evaluate diagnostic tests , it is less known what symptoms are more likely to be imitated by malingerers.methodin a prospective study 45 malingerers , who were diagnosed according to interviews by two forensic psychiatrists , from defendants with a judicial order for evaluation of mental status and criminal responsibility during a period of eighteen months were examined in legal medicine center of tehran . 
 participants were assessed in another interview to determine symptoms . 
 dichotomous symptoms in felony and misdemeanor groups were analyzed using fisher 's exact test . 
 the level of statistical significance was set at p < 0.05.resultsthirty-eight malingerers were charged with misdemeanors and seven with felonies . 
 behavioral symptoms were most frequently faked by 35 participants ( 77.8% ) . 
 participants charged with criminal accusation had a significantly lower mean age ( p=0.032 ) and a higher level of education ( p=0.008 ) than other non - criminal defendants . 
 a statistically significant increase in memory function problems was demonstrated in the misdemeanor group ( p=0.040 ) . with regard to dual symptom imitation 
 , statistically significant correlations were observed between thought content and perceptual symptoms ( p=0.048 ) for felonies and mood & affect and thought process symptoms ( p=0.034 ) , mood & affect and behavioral symptoms ( p=0.000 ) and cognitive function and behavioral symptoms ( p=0.039 ) for misdemeanors . in general , many simulators attempted to mimic simple symptoms of behavioral disorders . 
 probably felony offenses need less accurate programming ; therefore , their rates are higher in older , less educated participants.conclusionthis study demonstrated that differences between presenting symptoms among different offenses may not be useful in detection of malingering , ; however , unusual dual symptom imitations may be useful , particularly when standard tests are not performed .