My view:
i) Use of diagnostic concepts such as schizophrenia requires balancing reliability, validity, & utility, & there can be reasonable disagreement in how they are best balanced.
ii) I think if we have a) seasoned clinicians b) agreement over criteria c) additional data >> https://twitter.com/AnneCooke14/status/1339495083423502336

>> beyond self-report, such as observations of family members, hospital records, or longitudinal course, a diagnosis of "schizophrenia" (or even better "schizophrenia spectrum") is reliable to a reasonable degree.

iii) If we are concerned predominantly with reliability, it is not obvious that (psychological) formulation offers superior reliability over operational diagnostic criteria. In fact, conventional wisdom suggests the opposite.

iv) If we are concerned abt heterogeneity, focusing on delusions & hallucinations (sans diagnoses) is not an obvious solution to the problem of "muddled, heterogeneous groupings"; these symptoms are, in fact, far more heterogeneous, since you can have delusions in individuals >>

>> with dementia, substance intoxication, personality disorders, depression, mania, delusional disorder, or schizophrenia, to name a few.

v) Focusing on isolated symptoms such as hallucinations also makes the "boundary problem" far more difficult, since "hearing voices" is >>

>> fairly common in the general population, not always clinically relevant, characterized by marked heterogeneity, giving the illusion that "hearing voices" is a similar phenomena, whether that occurs during bereavement, mystical experience, or severe mental illness.

vi) Schizophrenia survives in psychiatry bcz of the tremendous utility it offers to psychiatric clinicians & researchers. However, this doesn't mean that the utility is necessarily carried over to other settings, such as psychological interventions, phenomenological inquiries, >>

>> service user perspectives, etiological research, & research frameworks such as RDoC and HiTOP, etc. This means that both within psychiatry as well as in other psy- professions, different concepts will offer different sorts of utility, & should be adopted correspondingly.

vii) My perception is that "schizophrenia" in contemporary practice designates "chronic psychosis not better explained otherwise", i.e. psychotic symptoms that do not resolve on their own within a short period of time & do not seem to be better explained by other medical & >>

>> psychiatric conditions. In such a situation, with full appreciation of the pragmatic nature of such a construct, disputing the label "schizophrenia" vs "psychosis" is at risk of becoming an argument abt labels rather than anything deeper.

viii) Avoiding understanding schizophrenia in an essentialistic manner, as a single, discrete, disease entity with an underlying common neurobiological disease process, doesn't necessarily require giving up schizophrenia as a clinically useful construct.