1. Introduction
1.1 Statement of the problem
The prison population is more than 10.2 million worldwide. Since the year 2000 the number of prisoners has grown by 20% (1). According to world prison population list report 2015, In Ethiopia about 111,050 peoples were in prison (2).Since the prison population growing rapidly worldwide the health and behavior of prisoners have become urgent social concerns (3). Number of prisoners in Africa is increasing from time to time due to many reasons including personality disorders (4). Among the common health and behavioral problems facing by prisoners mental illness is the most common. Study shows that 29% of prisoners had current mental illness (5). About 4 in 10 prisoners with mental condition are unemployed and 44% are recidivist (6).
Personality disorder define as an enduring pattern of behavior and inner experiences that deviates significantly from the individual’s cultural standards (7). Anti-social personality disorder is a persistent pattern of disrespect for, and violation of, the rights of others that begins in childhood or early adolescence and continues into adulthood (8). For this diagnosis to be given, the individual must be at least age 18 years. Individuals with anti-social personality disorder fail to conform to social norms. They may frequently perform acts which are ground for arrest, such as destroying property, harassing others, stealing, or illegal occupations (9). Even though there is no separate diagnosis between psychopathy and ASPD psychopathy is severe form of ASPD with a greater risk of violence (10).
Individuals with ASPD have high probability to be imprisoned due to their odd behaviors. Most of the time they charged with violent crimes such as murder, assault, armed robbery and kidnapping, non- violent crimes like fraud, theft, and housebreaking, sex crimes like rape and indecent assault and drug related offences such as possession of or dealing in illegal substances as a result they repeatedly imprisoned (4). It is common that up to 50% of the trial subjects diagnosed with ASPD, and many participants report behavior or symptoms associated with ASPD.
Personality disorders are common and it takes decades to be expressed, they present 10 to 20 % in the general population. The highest prevalence of antisocial personality disorder is found among men with alcohol use disorder and in prison population (11). Antisocial personality disorder is the most prevalent personality disorder among all personality disorders in prison population (12). It has been linked to a variety of executive functioning deficits, including poor cognitive control (13). Despite criminality and ASPD are not the same there is high prevalence of ASPD among prisoners (14).
Among peoples with ASPD there is 21.7 % of recidivism rate. This makes them nonproductive due to spending of their time in prison (4). According to a study conducted in the United States of America (USA) on mental health of prisoners 55 % of the prisoners didn’t get mental health service. Individuals with ASPD have high tendency to abuse substance, being offenders, disturb their family and the community (15,16).
A meta-analysis study reported that there is high risk of violent behavior among individuals with personality disorder. The Cause of ASPD remains unclear but some study shows the risk of developing ASPD increases with hereditary and being male (17). Antisocial personality disorder associated with a substantial impairment of the individuals. Moreover, the problem is not limited to the individual it has negative impact on the people surrounding them, such as spouse, children and at large the community (18).
Even though the problem is huge there is no well-studied about the ASPD and associated factors in our country. Having knowledge on ASPD among prisoners will help for intervention, planning of treatment and to decrease crime and recidivism.so this research will provide all the necessary information about antisocial personality disorder among prisoners.

1.2 Literature review
1.2.1 Magnitude of antisocial personality disorder
Epidemiological survey rates the prevalence of antisocial personality disorder 2 to 3% in community sample it increased to 60% in male prisoners (19). Antisocial personality disorder is highly prevalent in prison populations and likely to be present in 63% of sentenced male prisoners and 31% of female offenders from UK and Australia (20). A research from Germany conducted only on female inmates by using PCL-R and with the cut point score of 25 the prevalence rate of psychopathy was 17% (21). Another research from USA conducted on a sample of 288 men and 183 women by using structured interview for personality disorder (SIPD-IV) mentioned that from cluster B personality disorders among prison population the most prevalent one was ASPD with the prevalence of 57% among men and 36% women prisoners (22).
A cross sectional study conducted in UK on pre-sentence prison population with a total sample size of 283 by using international personality disorder examination-screening questionnaire (IPDE-SQ) the prevalence of ASPD was 25.8% (23). A cohort research conducted on randomly selected 191 prisoners who are consecutively admitted to prison in Netherlands reported that the incidence rate of ASPD was 37% (24). Another cross sectional study conducted in Italy shows that mental disorders are highly prevalent among prisoners, among which antisocial personality disorder was the first with the prevalence of 20% (25). A Swedish study conducted on forensic psychiatric patient samples 441 men and 123 women using the PCL-R 31% of men and 11% of women had ASPD (26).
A survey study on a sample of 496 sample in England and Wales using the schedules for clinical interview in neuropsychiatry, psychopathy checklist-revised and structured clinical interview for diagnostic statistical manual of mental disorder, for axis 2 personality disorders the prevalence of ASPD was 44.9% (10). A cross sectional study from Canada on a random sample of 495 prisoners sentenced inmates completed an interview of the diagnostic schedule 56% of them had ASPD (27). Other cross sectional study done in UK indicated that the prevalence of ASPD was 62 % by using PCL-R among 53 prisoners (28). A study done by using PCL-R among Dutch prisoners indicated that anti-social personality disorder was 34% (24). A meta-analysis study from Canada revealed that the prevalence of ASPD was 50% in male offenders and treatment reduce recidivism (29).
An institutional based cross sectional study among prisoner in Egypt a randomly selected sample of 1350 from different prisons, prevalence of personality disorder was13.6% among them ASPD was the most common with prevalence of 12.3% (30). A cross sectional research done in south Africa on 193 sample of prisoners by using mini neuro- psychiatric interview tool the prevalence of ASPD was 46.1% (4). A study from the USA reveals that the prevalence of ASPD among prisoners was 35.3% (31).Another study conducted in Iraq by using PCL-R reported that prevalence of ASPD was 32 % among prisoners (32).
A study done in Nigeria on 300 participants by using Antisocial personality Disorder self- test the prevalence of ASPD was 47 % in male and 21% females prisoners (33).
1.2.2 Determinants of anti-social personality disorders among prisoners
Antisocial personality disorder has an association with multiple problems , social and medical such as substance abuse, crime and deliberate self-harm (19).
Socio demographic factors DSM 5 indicated that ASPD is more frequently diagnosed in males than females (9). A literature review from Australia reveals that in community sample there is a real difference between male and female sex by using various assessment instruments and diagnostic manuals, the difference in prevalence between male and female is reported that 27.2% were males and 7.5% were females. Two to five-fold rats of ASPD is found in men but the difference becomes less in prison sample (34).
A study from Atlanta in USA there is a difference in the prevalence of ASPD in male and female inmates. The research was done using PCL-R with a cut -off score of 30 and 15% of women and 30% of male inmates were psychopathic (35) . Another study from Zambia mentioned that participants with single marital status were highly affected by mental illnesses including ASPD (36).
An epidemiological catchment area study from UK shows that socio demographic factors like being male, younger age and poorly educated have higher prevalence rate of ASPD. Being male have a prevalence of as high as 6-8 times more ASPD than female, and being young age (25-44) for both sex has high prevalence of ASPD than the older age individuals. ASPD was high for those who leaves school at the age of 11 it was 5 times higher than from those who remain at school (19). A cross sectional study from the USA reveals that ASPD is more prevalent among young ages than the old one (31). According to DSM-5 ASPD is high among those who are economically poor (9).
Substance related factors; A research from south Dakota of USA reported that there is association between alcohol use and prevalence of ASPD (37). Another study from the US indicates that most people from the community sample with ASPD are chronic cigarette smokers, alcohol and marijuana users (38). According to research conducted in turkey 31% of individual with ASPD are substance user (39)
The study conducted in Egypt among prisoners mentioned that the prevalence of ASPD in substance users was three times higher than non-users and the prevalence of ASPD is two times more common in those who have repeated admission to prison (30).
Clinical factors having other psychiatric disorder has 2.5 times increasing the prevalence of ASPD among prisoners than those without mental disorders (30).

1.2.3 Conceptual frame work