Table 1. Diagnostic classification in 37 twins participating in the CSF study.
| Diagnostic status | Twin subjects | Twins from concordant pair* | Twins from discordant pair | Twins from control pair | |
| MZ twins | DZ twins | ||||
| Schizophrenia | 4 | 3 | 5 | 2 | - |
| Schizoaffective disorder | 1 | 1 | 0 | 2 | - |
| Bipolar disorder type 1 | 4 | 1 | 1 | 4 | - |
| Bipolar disorder type 2 | 1 | 2 | 0 | 3 | - |
| Life-time depression | 6 | 3 | 0 | 5 | 4 |
| Not affected | 5 | 6 | 0 | 7 | 4 |
| Total | 21 | 16 | 6 | 23 | 8 |
*
Classified as concordant when both individuals in the pair were affected by schizophrenia, schizoaffective disorder or bipolar disorder.