Disorganized Schizophrenia

According to the evolutionary theory, the negative symptoms of the schizotypal capture and
exaggerate the social apathy of the more intact schizoid, and the positive symptoms
capture and exaggerate the more intact avoidant.
Alienated from others and marginal members of society, schizoid-based schizotypals
turn increasingly to solitary thoughts. Over time, shared social behaviors become fully
subordinate to private fantasy. Their thoughts are left to wander unchecked by the logic
and control of reciprocal social communication and activity. What they find within
themselves is hardly rewarding—a barren, colorless void that offers no basis for joyful
fantasy. Their inner personal world proves to be as dead and ungratifying as objective
reality. They have no choice, so it seems, but to turn to unreal fantasies. These, at least,
might fill in the void and give their existence some substance. Interest moves toward
the mystical and magical, to needed illusions and ideation that enables the person to
become a central, rather than a peripheral and insignificant, figure.

Feelings of being hollow, empty, decaying, or dead inside, for example, caricature
the depersonalized passive-detachment of the schizoid pattern. Lacking energy and initiative,
these individuals neither engage others nor generate anything to fill their own
internal void. Eventually, they exist only as living absence. Likewise, individuals
who claim access to special modes of information and privileged dimensions
of reality caricature the active-detachment of the avoidant, for whom hypervigilance
and the construction of a withdrawn fantasy life are core traits. As the structural defect
becomes more profound, it finally destroys integration itself as the defining characteristic
of personality. Only the negative and positive symptoms of schizophrenia remain,
residuals of the passive and active detachment of the schizoid and avoidant personalities.

It would seem that my father is an example of somebody that experienced just that: he disintegrated all the way to disorganized schizophrenia. It seems that a desire for a rich fantasy life and lack of emotion do not mix well, and my father would have found a way to cheat the system: take drugs to amplify his emotions, effectively making himself more numb and void over time, and at the end he was completely out of this world, fantasy-life speaking.

That's interesting because it explains just how a schizoid can turn schizophrenic, and exactly what way it happens.
schizoid => (schizoid-style) schizotypal => disorganized schizophrenia.
At the schizoid point you feel rather void, your personality lacks substance, and your emotional detachment interferes with your capacity to enjoy anything. If left unchecked or if you try to boost your emotions through chemical means, you can further disintegrate into schizotypal, where in addition to the void you add a general sense of slipping out of reality, and a mixing of reality and fantasy, making you unable to realise that mysticism and such are unrelated to reality since your inner world is too diffuse by now to get any sense of meaning anywhere, even at the intellectual level: you are now impared in your capacity to tell what is real from what is not. And it can disintegrate yet further into schizophrenia, where your inner world is just a total psychotic chaotic void. Funny, but that reminds me of the three "dimensions" in Silent Hill: "The Fog world" outside the dark places => "The Fog world" in the dark places => "The Otherworld".