1.4.2 Schizophrenia and Borderline Personality Disorder

The separation of manic depressive illness from schizophrenia was an important diagnostic task undertaken early on by Kraepelin (1896, 1919) who saw schizophrenia (“dementia praecox”) as a psychotic illness and a thought disorder, characterised by a steady downhill in cognition leading to chronic dementia, whereas manic depressive illness was seen as an episodic affective disorder with intermittent recovery. Although there is great heterogeneity in the symptom profiles of schizophrenia (or different schizophrenias), some of the primary symptoms of it such as delusions, hallucinations, disorganised behaviour (positive symptoms) and lack of insight can often appear in manic episodes to the extent that the two disorders may initially appear indistinguishable.