To study influence of forensic psychiatric diagnosis in case of criminal responsibility, treatment necessary and violence to court orders.

Samples were 301 inpatients of Galya Rajanagaridra Institute who were criminal offenders during year 2000-2007. Data were collected from medical records and reports of the judgments and prosecution. The data were analyzed by descriptive statistic.

The study found that most of samples were single, males who aged between 21-40 years old. They were unemployed and graduated primary school. Most of them were sent by courts. Murderers were found the most. Regarding to psychiatric diagnosis, most of them were psychosis and their motivation to crime were delusion and hallucination. Moreover, psychiatrists diagnosed that 125 samples (41.5 %) were not criminally responsible, 143 samples (47.5 %) needed treatment and 42 samples (14.0 %) were stated as violence. In those cases, 5 and 22 cases (1.7 and 7.3 %) were dropped the charge by police and district attorneys, respectively. Regarding to criminal responsibility according to the section 65 of Criminal Code, courts agreed with psychiatrist's diagnosis for 49.3 %. In case of treatment order according to the section 48 and 56 of Criminal Code, courts disagreed with psychiatrist's diagnosis for 64.1 % totally.

The study showed that forensic psychiatric diagnosis, in cases of criminal responsibility, treatment necessary and violence, moderately influenced to court orders. Thus, this leads to question to develop forensic psychiatric work in the future.