pretty spot on,

just because a medication helps by increasing neutrotransmitter activity doesn't mean those specific neurotransmitters are actually 'imbalanced' or even the cause of the mental illness in the first place,

as a very basic analogy;

alcohol for instance can promote confidence in social settings, especially those who aren't very socially comfortable for whatever reason (be it lack of social exposure, low self-esteem, social anxiety disorder, whatever) but the lack of confidence isn't due to a lack of alcohol, the alcohol in that context simply alleviates the symptoms caused by whatever the underlying symptoms through a certain mechanism of action that alters the way the brain responds to stumili, and then furthering that into intoxication,

the same can be said about anti-anxiety medications like valium/xanax,

adhd is kinda the same, increasing dopamine/norepinephrine activity in the brain helps to promote self-regulation and attention in ADHD individuals, but it does so through chemical interference of whatever the underlying issues leading to ADHD symptoms are, and in that sense, it's also unfair to suggest that everyone suffering from ADHD symptoms suffers from them for the same underlying reasons; though the general trend in science shows that it's most commonly an executive functioning disorder that emerges as a sort of delayed development;

ask yourself this, whether the delayed development is entirely biological, mental, or even as a result of parenting and environment, what difference does it make if that person reaches adult-hood without having developed executive functioning skills/habits/capabilities at the same rate as those around them?