Dandy Walker “syndrome” (DWS) was firstly defined by Dandy and Blackfan, and then described by Hart et al. [1] as a series of neurodevelopmental anomalies in the posterior fossa, including Dandy-Walker (DW) malformation, DW variant (cerebellar hypoplasia/aplasia of the cerebellar vermis and cystic dilatation of the fourth ventricle), mega-cisterna magna and posterior fossa arachnoid cyst. Mental symptoms have been associated with DWS in previous reports, but the spectrum of mental symptomatology widely varies between clinical cases, ranging from psychotic/schizophrenia-like to mood/cognitive symptoms [2].

Here we describe a case of psychosis and polydrug abuse in a 27-year-old man with DW variant a 4-year history of polydrug abuse, sporadic alcohol abuse, epilepsy and psychotic symptoms including delusions of reference/persecution, suspiciousness, associated with obsessive thoughts, mood lability and persistent anxiety.

He was recovered for a 28-day program of detoxification from drug addiction/stabilization of psychiatric symptoms. Family history of Bipolar Disorder, gambling disorder (father) and depression (mother). The mental status examination at baseline revealed slowness of thought, psychomotor retardation, aboulia/anhedonia/apathy/hypomimic facies/asthenia/social withdrawal/deflected mood/poor thought content/blunted affect/self-neglect/poor insight, cognitive impairment and oppositive and partially collaborative attitude and behaviour. Borderline intelligence activity was found on WAIS-R (IQ = 79). At the baseline, he was taking carbamazepine 400 mg BID (baseline serum level: 6.720 μg/ml), gabapentin (400 mg BID), paroxetine (20 mg/d), olanzapine (10 mg/d) and methadone (70 ml/d), with a poor response/control both on psychotic and seeking drug symptomatology.

References not available.

Further DWS clinical cases should be evaluated in order to better investigate the role of this variant to addictive and psychotic symptoms.

The authors have not supplied their declaration of competing interest.