In patients, the maximum mercury level recorded was 705 parts per million (ppm), indicating very heavy exposure and in nonsymptomatic Minamata residents, the level was 191 ppm. This compared to an average level of 4 ppm for people living outside the Minamata area.On 12 November 1959, the Ministry of Health and Welfares Minamata Food Poisoning Subcommittee published its results:

Minamata disease is a poisoning disease that affects mainly the central nervous system and is caused by the consumption of large quantities of fish and shellfish living in Minamata Bay and its surroundings, the major causative agent being some sort of organic mercury compound. 1959
During the Kumadai investigation, the causal substance had been identified as a heavy metal and it was widely presumed that the Chisso factory was the source of the contamination. Chisso was coming under closer scrutiny and to deflect criticism, the wastewater output route was changed. Chisso knew of the environmental damage caused by its wastewater and was well aware that it was the prime suspect in the Minamata disease investigation. Despite this, from September 1958, instead of discharging its waste into Hyakken Harbour (the focus of investigation and source of original contamination), it discharged wastewater directly into Minamata River.
In the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) it is instead considered a sub-category of the "Other Specified Obsessive-Compulsive and Related Disorder" category [300.3 (F42)], where variants of taijin kyofusho are "Shubo-kyofu [...] that is similar to body dysmorphic disorder and is characterized by excessive fear of having a bodily deformity" and "Jikoshu-kyofu [...] characterized by fear of having an offensive body odor".One source even breaks taijin kyofusho into two different subtypes: neurotic and offensive. The first subtype can be broken into two parts that are classical type and avoidant type. The classical type being afraid of being judged negatively because of physical signs of anxiety and feeling shame due to anxiety. The physical signs that can cause fear of being judged include sweating and tremors. The second subtype deals with people thinking something about them is offensive. Some of their fears include body odor, gas, excessive or insufficient eye contact, blushing, etc. In the official Japanese diagnostic system, taijin kyofusho is subdivided into the following categories:
Sekimen-kyofu (Japanese: 赤面恐怖), the phobia of blushing (ereuthophobia)
Shubo-kyofu (Japanese: 醜貌恐怖), the phobia of a deformed body, similar to body dysmorphic disorder
Jikoshisen-kyofu (Japanese: 自己視線恐怖), the phobia of eye contact
Jikoshu-kyofu (Japanese: 自己臭恐怖), the phobia of having foul body odor (also termed olfactory reference syndrome, osmophobia or bromidrosiphobia)Japan psychology also recognizes additional types of taijin kyofusho based on severity:

Transient: This type of taijin kyofusho is short-lived and moderately severe. It most commonly appears in teens, but may occur at any time.