Table 1.
Demographics for the healthy controls and individuals with schizotypal personality disorder (SPD).
| Characteristic | Healthy controls (n=38) |
SPD patients (n=33) |
||||||
|---|---|---|---|---|---|---|---|---|
| Mean | SD | Range | Mean | SD | Range | t value | p value | |
| Age (years) | 34.05 | 10.8 | 22–58 | 35.67 | 10.62 | 20–54 | Age: t(69)=−0.63 | 0.53 |
| Educationa | 5.0 | 2.82 | 1–9 | 4.36 | 2.09 | 1–8 | Education: t(69)=1.07 | 0.29 |
| Sex | n | % | n | % | Sex: | |||
| Male | 16 | 42% | 18 | 55% | t(69)=−1.04 | 0.30 | ||
| Female | 22 | 58% | 15 | 45% | ||||
| Handedness | n | % | n | % | Handedness: | |||
| Right | 34 | 89% | 28 | 85% | t(69)=−0.48 | 0.63 | ||
| Left | 3 | 8% | 4 | 12% | ||||
| Both | 1 | 3% | 1 | 3% | ||||
| Symptom severityb | – | – | 7.21 | 1.15 | 5–10.5 | |||
| Past MDDc | n | % | n | % | ||||
| – | – | 7 | 21% | |||||
| Psychoactive meds | n | % | n | % | ||||
| Never medicated | – | – | 27 | 82% | ||||
| Previously medicated | – | – | 6d | 18% | ||||
All study participants were interviewed by a psychologist using the Structured Clinical Interview for DSM-IV Axis I disorders (First et al., 1996) and the Structured Interview for DSM-IV Personality Disorders (SIDP-IV) (Pfohl et al., 1997) followed by a consensus meeting. Exclusion criteria included a history of schizophrenia, a psychotic disorder, bipolar (type I), or current (in the last 6 months) major depressive disorder (MDD). The SPD participants were free of psychoactive medication >2 weeks (majority were never medicated; see table for details). Healthy controls with an Axis-I or II psychiatric illness or an Axis-I diagnosis in a first-degree relative were excluded from the study. Exclusion criteria for all participants included the following: severe medical illness, neurological illness, head injury, past substance dependence, as well as substance abuse or dependence in the prior six months. All participants had a negative urine toxicology screen at the time of the study. All of the healthy controls and the majority of individuals with SPD (90%) were recruited through advertisement in local newspapers. The remaining three individuals with SPD were recruited through referrals from the outpatient-psychiatry clinic at Mount Sinai (these participants did not differ in symptom severity from the 30 recruited from the community and only one of the three had previously received psychoactive medication).
Education=highest degree earned: 1=no high school diploma; 2=GED; 3=high school diploma; 4=technical training; 5=some college, no degree; 6=associate degree; 7 = bachelor's degree; 8 = master’s degree; 9 = MD/PhD/JD/PharmD.
Symptom severity=sum of the severity ratings (see text for full description) for the DSM-IV SPD diagnostic criteria. As required for a DSM-IV diagnosis of SPD, individuals met at least five of the nine SPD criteria. To quantify the level of symptom severity for each patient, each of the DSM-IV criteria established during the SID-P interview was rated on a 4-point scale (0=absent, 0.5=somewhat present, 1.0=definitely present/prototypic, 2.0=severe, pervasive) and then summed using our previously published methods (e.g., Goldstein et al., 2009). Our intra-class correlation for the SID-P is 0.73 for the SPD diagnosis.
MDD=major depressive disorder; past MDD was defined as prior episode occurring >2 months from time of the MRI scan.
Of the 6 SPD patients who previously received psychoactive medications, 2 received an antipsychotic, 5 received an antidepressant, and 3 received a stimulant.