Clinical case review
Review the complete Psychology case, its five progressive clues, the diagnosis, and the clinical reasoning behind the answer.
Want to test yourself first? Play the original case before reading the clues and explanation below.
WhatsTheDx publishes a new Psychology case every day. Five clues, one diagnosis, and no account needed to play.
Play today's Psychology caseThese are the case findings in their original reveal order, moving from the broader presentation to the most discriminating evidence.
Clue 1
A 33-year-old bike mechanic comes in with his sister, who made the appointment for him. For about seven weeks he has been flat and heavy: he has stopped going to the workshop he part-owns, sleeps in broken pieces, and cannot see the point of much. He apologises twice for taking up the slot.
Clue 2
There is more here than low mood. For at least the past month he has been hearing a voice that narrates what he is doing, a running commentary from somewhere behind his left shoulder, and he is certain that a late-night radio show discusses him in coded terms. His speech is orderly and easy to follow, nothing about his behaviour is disorganised, and no negative symptoms are in evidence — but two of the listed features are clearly present, and two is the threshold. A structured assessment puts the current low period in the moderate band, up from mild at his review four months ago.
Clue 3
His sister has kept the dates, and they change the shape of this. Five years ago, across about ten weeks, he barely slept, spoke faster than anyone could follow, took on four jobs at once and finished none, and spent money he did not have. Two long depressive episodes followed — one of eight months, one of close to a year. Laid end to end on a calendar, the periods that met criteria for a major mood episode account for roughly four of the five years: most of the total duration of the illness, active phases and quieter ones alike.
Clue 4
One stretch of that calendar refuses to fit the rest. In the autumn of the third year, for about seven weeks, his mood was simply level — nothing low, nothing elevated. He was sleeping normally, back at the workshop, going to his niece’s football matches; he and his sister both remember it as a good spell. Through all seven of those weeks the voice kept up its commentary and the coded broadcasts went on exactly as before. Two weeks of that would have been enough.
Clue 5
The rest is housekeeping, and it still has to be done. The urine toxicology screen is negative, and neither he nor his sister reports alcohol or drug use around any of these periods. Cognitive screening is normal across every domain tested, with nothing to suggest a neurological or other medical cause. Nothing outside him accounts for any of it.
Diagnosis
Schizoaffective disorder is settled with a calendar rather than a test result, which is why this case is built as a timeline. Criterion A asks for two or more of delusions, hallucinations, disorganised speech, disorganised or catatonic behaviour, or negative symptoms, each present for a significant amount of time during a 1-month period: he has the voice and the fixed belief about the broadcasts. Criterion D asks that none of it be attributable to substance use or a medical condition, which the negative urine toxicology screen and the normal cognitive screening cover. The two criteria that do the real work need a history, not an examination. Criterion C requires that symptoms meeting criteria for a major mood episode be present for most of the total duration of the active and residual phases of the illness — here, roughly four of five years. Criterion B requires hallucinations and delusions for 2 or more weeks in the absence of a major mood episode, manic or depressive, at some point in the lifetime of the illness — here, the seven weeks in the third year when his mood was level, he was back at work, and the voice carried on regardless. That isolated stretch is the hinge of the whole case. The manic episode makes this the bipolar type; the depressive type has major depressive episodes only. Lifetime prevalence is around 0.3%, about one-third as frequent as schizophrenia. If you landed somewhere else, you are in extremely ordinary company: this is among the most frequently misdiagnosed psychiatric disorders in clinical practice, and the category itself is contested — some researchers have proposed revising the criteria and others removing the diagnosis from DSM-5 altogether. The term first appeared as a subtype of schizophrenia in the first DSM and only later became its own diagnosis, despite a lack of evidence for unique differences in aetiology or pathophysiology.
The explanation and decisive case findings were checked against the source below.
Open the clinical referenceFor education and entertainment only. This fictional case is not medical advice and does not replace supervised clinical training, diagnosis, or treatment.
