発達障害って部分的な知的障害である、このことについて精神科医が語ります。

Good evening. I'm Takahiro Haga, a psychiatrist. Today, I'd like to talk about the topic, "Developmental disorders are essentially a form of partial intellectual disability." The reason I decided to discuss this topic is twofold. Firstly, I was asked by a health center to give a lecture on developmental disorders this summer, and I wanted to reconsider this topic thoroughly. Secondly, I recently saw a patient who was experiencing the very essence of the difficulties associated with developmental disorders, and I felt it was necessary to articulate this clearly. The term "developmental disorder" has become quite widely used these days. However, I don't believe it's simply a vague concept like "we call it a developmental disorder because it makes life difficult." Developmental disorders are actually much more serious and deeply affect one's life. Therefore, today, I'd like to frankly share my thoughts on its essence. Generally, developmental disorders are explained as being divided into autism spectrum disorder, ADHD, and learning disabilities. Of course, this classification is important and necessary as a diagnostic criterion. However, simply understanding how many diagnostic criteria a person meets can be insufficient; it often obscures the true nature of the problem. I find this somewhat unsatisfactory. What's crucial is understanding "why that person is in that state" and "what is making their life so difficult." A patient I recently saw was perceived by those around them as having delusional schizophrenia. They were saying alarming things like they were being monitored by the Japanese government, being unfairly treated, and vowing to cause trouble in Kasumigaseki (the central government district). Their supporters and staff were genuinely frightened. That's why they contacted the health center for help. But when I actually spoke with them, I found that their overall intellectual ability wasn't low at all. In fact, judging from their educational background and conversation, they had a sufficiently high level of intelligence. However, in certain areas, their beliefs became extremely strong. For example, if the welfare application process didn't go smoothly, they would jump to conclusions like, "The supporters are hindering me," or "I'm suffering because they don't work." However, that idea can be surprisingly easily modified when explained logically and carefully. In other words, this is different from the uncorrectable delusions in schizophrenia. The belief is very strong, but it's not absolutely unshakeable. To discern this, clinical intuition as a psychiatrist is necessary. Looking only at the superficial words and actions, it might appear as a delusion. But the reality is slightly different. This is a crucial point. So, why do such strong beliefs arise? I believe one of the essences of developmental disorders is "difficulty integrating information." We live surrounded by a vast amount of information every day. Information from sight, information from hearing, the other person's facial expressions, tone of voice, the atmosphere of the place, past events, our relationship with the other person. Unconsciously, we integrate these things, weighting them as "important" and "not so important" to understand them. It is this integration process that allows us to grasp reality in a three-dimensional way. However, people with developmental disorders sometimes have difficulty with this weighting. For example, being slightly put on the back burner by a staff member. Normally, we would consider multiple possibilities, such as "Maybe they were busy," "Maybe they just forgot," or "Maybe it wasn't malicious." However, if we can't integrate these possibilities properly, the single point of "I'm being harassed" becomes disproportionately heavy. This quickly leads to a victim mentality, with thoughts strongly leaning towards being insinuated, bullied, or monitored. I believe that the "inability to read the atmosphere," common among people with ASD, can be largely explained by this weakness in information integration. For example, suppose someone says, "I hate cockroaches." Most people would consider the tone of voice, facial expression, frequency, and reaction when a cockroach actually appears to determine whether the person genuinely hates them, is joking, or just being flippant. But if this integration fails, they take that single statement literally. They can't gauge the degree of sincerity. These small discrepancies accumulate, making interpersonal relationships increasingly difficult. And even more serious is the difficulty in imagining how one's words will be received by those around them. The patient I mentioned earlier said something extremely extreme. However, from their perspective, they felt they were "just saying what they thought," "joking," and "didn't expect anyone to take it seriously." But when someone of a large physique says something like that, it's natural for the listener to feel intimi...