RICERCA ITALIANA     

Research program

Genetic and neural imaging aspects of antidepressant response

University Co-ordinator

Università degli Studi di BARI - SCIENZE NEUROLOGICHE E PSICHIATRICHE - BARI(BA)

Research Unit Leader

Alessandro BERTOLINO

Description

Phase 1:
In the first six months 40 healthy subjects will be recruited. Inclusion criteria for healthy subjects will be: age from 18 to 45 years, absence of psychiatric illness (Axis I and II, DSM-IV), absence of any organic brain damage, head trauma with loss of consciousness, neurological disease, mental retardation or any diagnosable disease, non-pregnancy or breast-feeding for females, HAM-D score <8.

Phase 2:
In the following 18 months, 24 patients with Major Depression will be recruited. Inclusion criteria will be: age from 18 to 45 years, absence of co-morbid DSM-IV psychiatric illness (Axis I and II), absence of any organic brain damage, head trauma with loss of consciousness, neurological disease, mental retardation or any diagnosable disease, non-pregnancy or breast-feeding for females. A minimum score of 18 at the Hamilton Depression Rating Scale will be necessary for inclusion in the study. Diagnosis of MDD will be established using the Structured Clinical Interview for DSM-IV (SCID) administered by two board certified psychiatrists. Patients will only be eligible if illness duration is no more than 24 months and they have been free from medication for a minimum of 2 weeks. Patients with suicidal ideation or behaviour will be excluded.
In this phase, data will also be collected from a group of 24 healthy subjects (recruited by word of mouth) matched for age, gender, socio economic level and ethnicity, IQ. Inclusion criteria will be the same as phase 1.

The protocol will be submitted to local IRB approval. Informed consent for all procedures will be obtained from all subjects prior to data collection.



Procedures

Phase 1:
Once subject's eligibility to participate is determined, testing and data collection appointment(s) will be scheduled for (a) data collection and tests administration, (b) Venipuncture and blood draw (Genetic analyses), (c) Functional Magnetic Resonance Imaging (brain).


a)Clinical/Diagnostic Interview and Medical Examination
Clinical and diagnostic interviews will last from 30 to 90 minutes, as needed. Depressive Symptoms will be assessed with the Hamilton Depression Rating Scale for Depression (HRSD-21). Further clinical assessment, including physical examination, will be performed to exclude any medical condition. A series of other demographic variables will also be collected, including: IQ, handedness, education, and parental socioeconomic level.

b)Venipuncture and blood draw (Genetic analyses).
Subjects will be asked to provide a blood sample. Three tubes of blood (about 30 ml) will be used for DNA extraction and creation of cell lines. Genomic DNA will be extracted from peripheral blood or immortalized lymphocytes according to standard procedures. PCR amplification will then be performed. SNPs genotyping will be performed using Restriction Fragment analysis Polymorphisms (RFLP)

c)Functional Magnetic Resonance Imaging
Neuropsychological Task: The fMRI paradigm will consist of two blocks of an emotion task interleaved with three blocks of a sensorimotor control task[43]. Each block will last 33 seconds (total duration 2 min 45 sec).During the emotion task, subjects will see a trio of unfamiliar faces and they will match one of two simultaneously presented images with an identical target image. Each emotion block will consist of six images, three for each gender and target affect (angry or afraid). These images are part of a standard set of pictures of facial affect.During the sensorimotor control, subjects will see a trio of simple geometric shapes (circles, vertical and horizontal ellipses) and they will select one of two shapes (bottom) identical to the target shape (top). Each control block will consist of six different images. Subject performance will be measured as accuracy (percent correct responses) and reaction time (msec).

Images acquisition and fMRI data processing:
fMRI data will be acquired using a GE Signa 3T scanner (gradient echo EPI sequence, TR/TE = 3000/30 msec, FOV = 24 cm, matrix = 64 x 64, flip angle = 90, voxel size = 3.75, 3.75, 5 mm, 24 axial contiguous slices, 5 mm thickness). All fMRI data will be analyzed within SPM99. First level analysis will be performed to obtain activation maps for each individual during the execution of the neuropsychological task. We will specifically apply t-statistics to evaluate the BOLD signal difference between the execution of the affective and the sensorimotor control task. We will further perform second level group analysis applying random effect models to determine task-specific regional activity in amygdala. ANOVA will be performed to look at the differential amygdala activity according to SERT genotype.

Phase 2:
The same procedures followed in Phase1 will be applied to healthy subjects that agree to participate to the study.
Once eligibility to participate has been determined for patients, testing and data collection appointment(s) will be scheduled for (a) clinical data collection, tests administration and pharmacological treatment planning, (b) Venipuncture and blood draw (Genetic analyses), (c) Functional Magnetic Resonance Imaging (brain).


a)Clinical and diagnostic interviews (SCID) will last from 30 to 90 minutes, as needed. Depressive symptoms will be assessed with the following rating scales: the Hamilton Depression Rating Scale for Depression (HRSD-21). The Medical Outcomes Survey Short Form-36 (SF-36) will be used for assessment of outcomes. Further clinical assessment, including physical examination, will be performed to exclude any medical condition. A series of other demographic variables will be also measured including: IQ (WAIS-R), pre-morbid IQ (Italian version of the WRAT), handedness (Edinburgh Handedness Survey), education, and parental socioeconomic level. Patients included into the study will be treated in monotherapy with sertraline (100-200 mg daily) and will be assessed with the (HRSD-21) at baseline and after 2 and 8 weeks of treatment. In case of no response (absence of 50% reduction at HDRS-21 scores after 6 weeks of treatment) the drug can be modified according to the routine of the unit. Low dosages of benzodiazepines will be allowed in the first 10 days of treatment (15-30 mg flurazepam or equivalents).

b)Venipuncture and blood draw (Genetic analyses): as Phase 1

c)Functional Magnetic Resonance Imaging:
All patients will be scanned twice: after 2 weeks and 8 weeks of treatment with Sertraline. Healthy subjects will be scanned once.

Neuropsychological Task: see Phase 1
Images acquisition and fMRI data processing: see Phase 1 for data acquisition and first level analysis.
Random effects model will be used for group analysis (t-test). Analysis of variance will be performed to evaluate both the differential amygdala activity in patients and healthy subjects (between group analysis) and the effect of treatment with sertraline (within group analysis).