Map of Penwortham on schizophrenic adj. schizophreniform disorder a disorder whose essential features are identical to those of schizophrenia except that the total duration is between 1 and 6 months and social or occupational functioning need not be impaired. schizophrenogenic adj. denoting a factor or influence viewed as causing or contributing to the onset or development of schizophrenia. For example, schizophrenogenic parents are those whose harmful influences are presumed to cause schizophrenia in their offspring; this concept the subject of much debate in the 1940s especially is now considered an oversimplification. schizotypal personality disorder a personality disorder characterized by various oddities of thought, perception, speech, and behavior that are not severe enough to warrant a diagnosis of schizophrenia. Symptoms may include perceptual distortions, magical thinking, social isolation, vague speech without incoherence, and inadequate rapport with others due to aloofness or lack of feeling. Map of Penwortham 2016.