The incidence in Caucasians is reported as 1 in 1,339 live births, compared with 1 in 143 live births in Africans and African Americans. Ulnar polydactyly is also often part of a syndrome. In patients with African ancestry ulnar polydactyly mostly occurs isolated, whereas the presentation in Caucasians is often associated with a syndrome, though in a retrospective review, only 4 of 37 cases of ulnar polydactyly in Caucasians were syndromic. Radial or preaxial polydactyly
This is a less common situation, in which the affectation is on the side of the hand towards the thumb. Radial polydactyly refers to the presence of an extra digit (or extra digits) on the radial side of the hand. It is most frequent in Indian populations and it is the second most common congenital hand disorder. The incidence of radial polydactyly is reported as 1 in every 3,000 live births. The clinical features of radial polydactyly will depend upon the extent of duplication. Radial polydactyly varies from a barely visible radial skin tag to complete duplication. Thumb polydactyly varies from barely visible broadening of the distal phalanx to full duplication of the thumb including the first metacarpal. Radial polydactyly is frequently associated with several syndromes. Central polydactyly
This is a very rare situation, in which the extra digit is on the ring, middle or index finger. Of these fingers, the index finger is most often affected, whereas the ring finger is rarely affected. This type of polydactyly can be associated with syndactyly, cleft hand and several syndromes.
Psychasthenia was a psychological disorder characterized by phobias, obsessions, compulsions, or excessive anxiety. The term is no longer in psychiatric diagnostic use, although it still forms one of the ten clinical subscales of the popular self-report personality inventories MMPI and MMPI-2. Signs and symptoms
The MMPI subscale 7 describes psychasthenia as akin to obsessive-compulsive disorder, and as characterised by excessive doubts, compulsions, obsessions, and unreasonable fears. The psychasthenic has an inability to resist specific actions or thoughts, regardless of their maladaptive nature. In addition to obsessive-compulsive features, the scale taps abnormal fears, self-criticism, difficulties in concentration, and guilt feelings. The scale assesses long-term (trait) anxiety, although it is somewhat responsive to situational stress as well. The psychasthenic has insufficient control over their conscious thinking and memory, sometimes wandering aimlessly and/or forgetting what they were doing. Thoughts can be scattered and take significant effort to organize, often resulting in sentences that do not come out as intended, therefore making little sense to others. The constant mental effort and characteristic insomnia induces fatigue, which worsens the condition. Symptoms can possibly be greatly reduced with concentration exercises and therapy, depending on whether the condition is psychological or biological. History
The term "psychasthenia" is historically associated primarily with the work of Pierre Janet, who divided the neuroses into the psychasthenias and the hysterias, discarding the term "neurasthenia" since it implied a neurological theory where none existed.