Some of the Führers physical ailments the uncontrollable trembling of his left arm and hand suggest, as noted earlier, a form of Parkinsons disease, but mentally Hitlers traits put him at least somewhere on the autism or Aspergers spectrum, possibly with extreme pathological demand avoidance (PDA) syndrome, which can develop in childhood. Sufferers typically exhibit obsessive behaviour, a lack of boundaries, avoid everyday work and social demands due to their own high anxiety levels, and feel they are not in control. They often possess great communication skills, but in appearing charming when feeling secure, they lack depth in their understanding of colleagues and intimates, and suffer excessive mood swings, often switching violently with a Jekyll and Hyde tendency, having real problems controlling their temper, which can take the form of prolonged tantrums and violent outbursts. Speer observed these increase in frequency as the war drew on; in one conference at which he presented unwelcome statistics, That alone made Hitler nervous and angry. Although he listened, I could see by his expression, by the lively fluttering of his hands, the way he chewed his fingernails, that he was growing increasingly tense . . . When I had finished . . . Hitler was no longer in control of himself. His face flushed deep red; his eyes turned lifeless and fixed. Then he roared at the top of his lungs . . . Abruptly, he terminated the conference, cutting off all further argument.