Objective: The current study attempts to define the psychological features of patients with delayed sleep-phase syndrome (DSPS).
Method: We administered the Yatabe-Guilford test (Y-G test), Minnesota Multiphasic Personality Inventory (MMPI), Picture-Frustration study (P-F study) and Rorschach test to two groups, one of patients with DSPS (case group) and the other of people without psychiatric symptoms or insomnia (control group).
Results: Overall, the results of the tests indicate that patients with DSPS showed emotional features such as nervousness, depression and lack of control of emotional expression. Specific personality traits included introspection, defensiveness, aspiration for intellectual attainment with compulsivity, overly abstract thinking, unawareness of impulsivity to immediate gratification, perseverance and reduced cognitive ability. In addition, the patients with DSPS showed psychopathological features similar to those of neurosis, hypochondriasis, depression, conversion hysteria and psychopathic deviate.
Conclusions: There seems to exist a definite psychological profile for patients with DSPS. (1) an excessive defense mechanism that increases nervousness and develops neurosis; (2) a high level of intellectual aspiration with compulsivity that makes the patients feel self-defeated, powerless and disappointed; (3) a tendency to egocentric emotion, inhibition and perseverance. These characteristics may worsen social withdrawal, causing a loss of social cues in synchronizing their circadian rhythm. Thus, the phase shift becomes more difficult and a vicious circle is constituted.