Table 1.
Characteristics of Studies Included in Meta Analyses of 5-HTTLPR Genotype, Stressful Life Events, and Depression
| Source | Total No. of Participants (No. Women) | Age, Mean (Range), y | Genotype of Participants, %a |
Study Design | Siblings/Twins | Life Events Measure | Depression Measure | Findings | ||
|---|---|---|---|---|---|---|---|---|---|---|
| LL | LS | SS | ||||||||
| Caspi et al,10 2003 | 847 (407) | 26 | 31 | 51 | 17 | Prospective cohort | No | Study-specific | Major depression (DSM-IV) | Interaction between the number of stressful life events and the number of 5-HTTLPR S alleles on the risk of depression |
| Original data provided by investigators | ||||||||||
| Eley et al,18 2004 | 377 (220) | 16 (12-19) | 17 | 54 | 29 | Cross-sectional | 22% Sibling pairs | List of Threat-ening Eventsa | Mood Rating Scale | Replication in female sex only |
| Gillespie et al,19 2005 | 1091 (666) | 39 (19-78) | 30 | 48 | 22 | Cross-sectional | Twins | List of Threat-ening Eventsb | Major depression (DSM-IV) | Failed to replicate |
| Grabe et al,20 2005 | 976 (673) | 52 (20-79) | 37 | 47 | 16 | Cross-sectional | No | Study specific | Somatic and psycho-logical Distress scale | Replication in female sex only |
| Surtees et al,25 2006 | 4175 (1950) | 60 (41-80) | 33 | 49 | 18 | Cross-sectional | No | List of Threat-ening Eventsb | Major depression (DSM-IV) | Failed to replicate |
| Wilhelm et al,27 2006 | 127 (85) | 48 (44-52) | 30 | 49 | 21 | Prospective cohort | No | List of Threat-ening Eventsb | Major depression (DSM-IV) | Replication |
| Taylor et al,26 2006 | 118 (67) | 21 (18-29) | 25 | 48 | 27 | Cross-sectional | No | Study-specific | Beck Depression Inventory | Partial replication (SS genotype only) |
| Chorbov et al, (2007)17 | 247 (247) | 22 (13-23) | 36 | 48 | 16 | Prospective cohort | Twins | Study-specific | MajorDepression (DSM-IV) | Failed to replicate(opposite direction) |
| Middeldorp et al,29 2008 | 1154 (785) | 39 (26-65) | 33 | 49 | 19 | Prospective cohort | Twins | Study-specific | Anxiety-Depression Rating Scale | Failed to replicate |
| Chipman et al,16 2007 | 2095 (1089) | 23 (20-24) | 33 | 46 | 21 | Cross sectional | No | List of Threat-ening Eventsb | Depression rating scale | Failed to replicate |
| Cervilla et al,15 2007 | 737 (529) | 49 (13-75) | 26 | 50 | 24 | Cross-sectional | No | List of Threat-ening Eventsb | Major depression (ICD-10) | Replication |
| Data from published articles | ||||||||||
| Kim et al,30 2007 | 732 (425) | ≥65 | 13 | 34 | 53 | Prospective cohort | No | List of Threat-ening Eventsb | Clinical depression | Replication |
| Power et al,31 2008 | 1421 (831) | ≥65 | 24 | 47 | 29 | Prospective cohort | No | Study-specific | Major depression (MINI) | Failed to replicate |
| Laucht et al,32 2009 | 309 (167) | 19 | 34 | 51 | 15 | Cross-sectional | No | Study-specific | Major depression (DSM-IV) | Failed to replicate (opposite direction) |
Abbreviations: DSM-IV, Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition); ICD-10, International Statistical Classification of Diseases, 10th Revision (ICD-10); SCID, structured clinical interview for DSM-IV disorders.
a
Percentages may not sum to 100 due to rounding.