Indian Journal of Psychological Medicine
  Home | About Us | Editorial Board | Search | Ahead of print | Current Issue | Archives | Instructions | Contact | Advertise | Submission | Login 
Users Online: 460 
Wide layoutNarrow layoutFull screen layoutHome Print this page Email this page Small font sizeDefault font sizeIncrease font size

Year : 2008  |  Volume : 30  |  Issue : 1  |  Page : 24-31 Table of Contents   

Study of effects of modafinil add-on therapy on excessive day time drowsiness and weight gain in patients on atypical antipsychotics

Professor of Psychiatry, S.V.R.R. Hospital, Tirupati, A.P., India

Correspondence Address:
T P Sudhakar
S.V.R.R. Hospital, Tirupati, A.P.
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0253-7176.43131

Rights and Permissions

How to cite this article:
Sudhakar T P, Rao G P, Prasuna P L, Vijay Sagar K J. Study of effects of modafinil add-on therapy on excessive day time drowsiness and weight gain in patients on atypical antipsychotics. Indian J Psychol Med 2008;30:24-31

How to cite this URL:
Sudhakar T P, Rao G P, Prasuna P L, Vijay Sagar K J. Study of effects of modafinil add-on therapy on excessive day time drowsiness and weight gain in patients on atypical antipsychotics. Indian J Psychol Med [serial online] 2008 [cited 2020 Mar 28];30:24-31. Available from:

   Introduction Top

Since the introduction of conventional anti­psychotics in the treatment of various psychotic disorders in late 1950's the quest for better molecules continued. The reasons for the betterment resulted in the introduction of second generation antipsychotics (SGA's) which are supposed to be more patient friendly with lesser extra pyramidal symptoms lesser chances of inducing tardive dyskinesia and better impact on affective, cognitive and negative symptoms of the schizophrenia. The initial enthusiasm about SGA's within 5 yrs had settled down towards skeptical optimism to control the unwanted and potentially endangering metabolic side effects.

Among the newer drugs except for Aripriprazole and to some extent Ziprasidone all other drugs produce significant weight gain and predispose the individual for hyperglycemia and hyperlipedemia. They also produce significant day time drowsiness which interferes with patients daily occupational activities.

The land mark study on antipsychotic efficacy, safety and tolerability namely CATIE study had clearly shown that 74% of the patients discontinued the treatment before 18months of trial. Intolerability was one of the major reason for the discontinuation, weight gain & metabolic effects with Olanzapine was established in phase II, part of the study. However, the trend for metabolic syndrome is also noticed with Clozapine, Risperidone, Olanzapine and to some extent with Quetiapine, Ziprasidone.

The other major side effect that discourages the patient to continue the treatment is daytime drowsiness. Though with dose titration this side effect can be minimized, most of the patients do not continue, because day time drowsiness interferes with their daytime work performance. So, to improve the compliance with atypical antipsychotics and to give the patients a better quality of life, it becomes imperative that we should find various strategies including pharmacotherapy and diet control.

Modafinil is a novel, non amphetamine psycho stimulant though it is not a typical sympathomimetic amine and has only weak affinity for dopamine uptake carrier site. It also acts on anterior hypothalamic nucleus and adjacent area. It is currently being promoted for excessive daytime sleepiness that occurs in Narcolepsy and also sleep apnoea. In 5% of cases it is known to produce anorexia and increase the alertness.

In this, study we are making an attempt to explore whether, a non amphetamine drug like modafinil for reducing daytime drowsiness, would be of any utility in preventing daytime drowsiness associated with atypical antipsychotics. As this drug also has got anorexia and weight loss as adverse events, it would be worth while to see, whether add on therapy of modafinil with atypical especially Olanzapine, Risperidone, Clozapine (widely prescribed atypicals in India) would in anyway influence the daytime sleepiness, weight gain, hyperglycemia & hyperlipidemia.

   Review of Literature Top

Atypical Anti Psychotics Versus Conventional Antipsychotics.

Conventional antipsychotic agents which have been the mainstay of treatment in Schizophrenia and other psychotic disorders for over forty years have a number of limitations. This had prompted a search for new agents with greater efficacy and fewer side effects. So the serotonin dopamine antagonists (SDA) (Janssen et al ,1988) came into the practice which is at present the mainstay of treatment in patients with schizophrenia and other psychoses.

But atypical antipsychotics are also not without side effects. Atypicality mainly refers to infrequent occurence of extrapyramidal syndromes in clinical setting. During recent years, it was found that akathisia is still common and tardive dyskinesia is also not uncommon with atypical drugs as earlier thought. Hence Second Generation Anti psychotics would be a better name that was suggested for this group of drugs.

Atypicals are not without other unwanted side effects. Most of the patients commonly gain weight to abnormal and unwanted proportions (Allison et al). They also experience excessive daytime drowsiness. The estimated prevalence of obesity in this population is three fold to that of the general population (Coodin S, 2001). An unhealthy diet and life style, environmental factors, negative syndrome, and direct effects of antipsychotic medication may predispose schizophrenics to weight gain .

Weight gain is distressing to most patients with schizophrenia who experience it and it may affect their response to treatment. Weight gain is also associated with treatment non compliance. It also leads to several serious medical conditions, development of metabolic syndrome( Alexander CM et al 2003) on long term usage, type II Diabetes Mellitus, Hypertension , Arthritis, Cerebro vascular diseases, Cardio vascular diseases , Pulmonary diseases, sleep apnoea and Cancer.

Most of the patients on atypical antipsychotic like Olanzapine, Risperidone, Clozapine etc., commonly experience excessive daytime sleepiness as a common adverse effect, which interferes with their day time work performance and affect their quality of life. This along with abnormal weight gain may be one of the factors responsible for non compliance.

Atypicals usage invariably produce clinically significant body weight gain over a period of time, leading to production of metabolic syndrome, increasing the risk for Diabetes Mellitus, Hypertension, and hyperlipi-demia.This would lead to increased susceptibility for Cerebrovascular and Cardiovascular accidents.


This review of literature assesses the various body weight gain liabilities associated with atypical antipsychotics, as well as the effects of body weight gain on quality of life. Most study reviews indicate that clozapine and olanzapine were associated with more body weight gain than the other atypicals.

Lambert MT et al compared one year incidence of new onset type II Diabetes Mellitus and changes in weight in patients with a variety of psychiatric diagnoses with atypicals is compared with typicals. It showed that in group who has received atypicals showed glucose intolerance and weight gain in comparisons to patients received typicals.

The two year follow-up study (McKee JR et al, 2005) came out with the conclusion that atypicals showed statistically significant increase in Body Mass Index (BMI), in addition to raising the levels of fasting Blood Glucose and lipids.

The Hallmark study CATIE conducted to look into the tolerability and adverse events associated with newer antipychotics (clinical antipsychotic treatment intervention effectiveness), also concluded both in Phase I and Phase II that the metabolic side effects of antipsychotics on patients with atypicals resulted in the development of metabolic syndrome among 40% in schizophrenia to that of 20% among the age matched normals(Newcomer JW, Medscape CME)


In this study, it was hypothesized that Modafinil, a centrally acting alpha 1 adrenergic drug which was approved by US Food and Drug Administration as a treatment for Narcolepsy, other conditions associated with Sleep apnea syndromes and sleep shift conditions shall help in minimizing the unwanted drowsiness. As the clinical experience and SPC of the drug also mentions Anorexia as one of the side effects, it was further hypothesized that it shall also control the weight gain associated with the atypical antipsychotic therapy. This loss of weight that may take place is considered as a direct result of lesser carbohydrate and fat intake by the subject.

Modafinil is a memory improving and mood brightening novel psycho stimulant. It enhances wakefulness and vigilance but its pharmacological profile is notably different from the amphetamines. Modafinil is less likely to cause Jitteriness, anxiety, excess locomotor activity or lead to rebound hypersomnoloscence than the traditional stimulants. Subjective experience of most of the patrients had been that it felt smoother and cleaner. The half life of modafinil is between 12-15 hrs. It is a safe effective and well tolerated agent.

Modafinil induces wakefulness in part by its action in the anterior hypothalamus. Its dopamine releasing action in the nucleus accumbens is weak and dose dependent.. Modafinil has central alpha 1 adrenergic against effects and inhibits the reuptake of noradrenaline by the noradrenergic terminals on sleep promoting neurons of ventrolateral preoptic nucleus (VLPO) more significant ability is to increase excitatory glutamatergic transmission. This reduces local GABAergic transmission.

Modafinil is clinically proved drug for treatment of narcolepsy , a neurological disorder marked by uncontrollable attacks of daytime sleepiness.

In Jan 2004 modafinil is approved by USFDA for the treatment of excessive sleepiness associated with obstructive sleep apnoea, and shiftwork sleep disorder, apart from its original application for narcolepsy. The most common adverse event reported in clinical studies were headache, most were transient and mild to moderate intensity.

Anectodal Evidences about Modafinils' Usefulness:

Massachusetts general hospital schizophrenia program freedom clinic, Boston reported a case on the impact of modafinil on weight in a clozapine treated patient. A patient on clozapine along with modafinil followed for three years. After one year patient experienced a weight loss of 40 lbs (280 lbs to 240 lbs) and a reduction in BMI of 5.08kg/m 2 and after three years this weight stabilize at 230 lbs (BMI = 29.59 kg/m 2 ).

A 30lb weight gain occurred following discontinuation of modafinil they concluded that modafinil treatment resulted in a significant weight loss possibly due to reducing clozapine associated fatigue.

Makela EH et al had reported in three cases the use of Modafinil was successful, in treating sedation induced by antipsychotic medication.

In this proposed study, based on this available information on Modafinil, an attempt was made to study the utility of Add on of Modafinil to patients with treatment emergent unwanted adverse events with Olanzapine, Risperidone and Clozapine. These drugs were chosen, because they are the commonly prescribed atypical drugs for their cost effectiveness in India.

   Materials and Methods Top

Type and Design of the Study;

Present study is a Randomized, Double blind, Placebo controlled study, which was conducted at two centers, i.e .one at department of Psychiatry, S.V Medical College, Tirupati and other was at Asha hospitals , Hyderabad.

All patients who fulfilled the inclusion and exclusion criteria were explained about the study in detail and a written informed consent was obtained. After obtaining the ICF, by using double blind placebo control technique the patients were randomly assigned to either placebo or Modafinil, by sponsor.

After randomization all baseline parameters like height, weight noted and BMI was calculated. CGI- S, BPRS, VAS, EDD scales given and scores noted.

The assessments were carried out again at week 3 and week 12.The doses of Olanzapine, Risperidone, Clozapine kept flexible according to the patient clinical condition .The dose of Modafinil was kept fixed at 200 mg.

All the adverse events those occurred during study period were promptly noted and required action was taken. Deviation from the treatment protocol was noted whenever there was a risk to the patient. Patient safety was kept in mind throughout the period of the study. Only those cases who have completed the 12 weeks study were taken up for statistical assessment .The reasons for the deviations and dropouts were evaluated separately.

The results were analyzed statistically and discussed. Limitations and strengths of study were also mentioned.

   Methodology Top


Primary Objective

  1. To evaluate the effect of add on Modafinil therapy on the weight gain and daytime drowsiness caused by atypical antipsychotics

Secondary objectives:

  1. To evaluate the tolerability of Modafinil
  2. To study whether Modafinil affects the efficacy of atypical antipsychotics

Study Sample

At baseline there were 72 patients, out of that only 63 completed the total study period. All the patients after fulfilling the inclusion and exclusion criteria were taken into the study. Written Informed consent was obtained after explaining the study procedure in detail. They were given the choice to voluntarily withdraw from the study without ascribing any reason. The institutional ethics committee had accorded approval for the study.

Inclusion Criteria;

  1. Any sex, Aged above 18 years.
  2. Patients who were on atypical antipsychotics for less than two weeks, irrespective of diagnosis.
  3. Those patients who could read and understand the ICF.

Exclusion Criteria

  1. History of consuming any anti obesity drugs or regimens.
  2. History of having taken atypical antipsychotics for more than three months in the last past five years.
  3. History of any coexisting metabolic illness including all endocrinal disorders.
  4. History of patients consuming corticosteroids, anabolic steroid and oral contraceptive pills.
  5. History of dual diagnosis on axis 1.on DSM IV
  6. Prolonged history of concomitant use of sedatives or tranquilizers.
  7. When the patient was kept on a was a mood stabilizer or an antidepressant.
  8. Patients who were highly uncooperative, destructive or suicidal.
  9. Patients who were stuporosed or required ECT.

   Scales used in the Study Top

A. EFFICACY ASSESSMENT SCALES: Mainly carried out to find out whether Modafinil interfered with the outcome of psychosis.

  1. Brief psychiatric rating scale
  2. Clinical Global Impression


  1. Visual Analog Scale (VAS)
  2. Excessive Daytime drowsiness scale (EDD)

Physical Assessments:

Weight measurement was done at baseline, week 3and at week 12 done by using same weighing machine to maintain the consistency. Abdominal girth is measured at level of umbilicus by using a flexible tape.

Statistical Methods

After unblinding the data was coded. Analysis of data was done by using SPSS 10.0 version. The placebo group and the Modafinil group characterstics were made out by using the descriptive statistics like frequencies, means, standard deviations . Non Parametric statistics like paired t test was used, for with in the group comparisons at baseline, at the end of the study and between the groups comparison.


The total number of patients, who had signed the written Informed Consent Form during the recruitment period and accepted to participate in the study from two centers in Tirupati and Hyderabad, amounted to seventy two. They were randomly assigned to either Modafinil or placebo as an addon for a period of twelve weeks. At the end of the study, it was found that only sixty three completed the study protocol and considered for the analysis. They were analyzed on socio demographical, disease related, Physical and Sleep parameters for the period of the study.

Patients completed the total study period - 63

Patients who did not completed the study-9

Out of nine patients who did not complete the protocol the reasons for non completion were ascertained as far as possible.[Table 1],[Table 2]

Headache and trouble falling asleep appeared to be two main reasons for these patients to withdraw early from the study in Modafinil group. Except for these two reasons, there was not much difference between placebo and Modafinil group.

The unblinding was done by the sponsor who had provided Modafinil, the Investigational Product and a similar looking placebo capsules. This was done after the last subject completed the study protocol after a written request from the investigating sites.

After unblinding it was found that among the sixty three subjects who completed the protocol Thirty one were allocated to Placebo and Thirty two to Modafinil.

All the analysis was carried out on these two groups to test the Hypothesis.

The following table shows the characteristics of age, sex, Diagnosis and Medication [antipsychotic used] in these two groups.[Table 3],[Table 4],[Table 5],[Table 6],[Table 7],[Table 8],[Table 9],[Table 10]

Comparisons were made between Modafinil and Placebo groups at baseline and also within the groups over 12 week period. The following conclusions were obtained:

In placebo group:

1. From baseline to week12 there was a gradual and significant raise in the weight ,BMI and ABG.

2. Sleep parameters like VAS1 [quality of sleep] showed significant improvement from baseline to week3 and to week 12.

3. VAS2 [daytime drowiness ] was increased over a period of time .that was from baseline to week 3 and also at week 12.

In Modafinil group:

whereas in modafinil group weight, BMI decreased ,when base line was compared with week3 and week 12.

4. Sleep parameters VAS 1[quality of sleep] was improved significantly.

5. VAS2 [daytime drowsiness] decreased significantly over a period of time.

6. Efficacy parameters like BPRS, CGI-S improved significantly in both the groups. It clearly shows that Modafinil did not exacerbate or worsen the existing psychotic features.

   Discussion Top

Impact of Modafinil on Resolution of Psychotic Features:

From the results it was obvious that Modafinil no way interfered with antipsychotic action of the drug. It was proved by the significant improvement of BPRS and CGI-S scores when compared from baseline to week 3 and also at end of the study that was at week 12.There was no significant difference between placebo and Modafinil in improving the psychotic features. It clearly proves that Modafinil did not have any potential to exacerbate the psychosis. So in conclusion Modafinil could be safely administered with atypical antipsychotics.

Common Adverse Events Noted in the Study Period:

During the total 12 weeks of study period only few adverse effects were noted which were only mild in intensity and resolved on their own over a period of time. Following were the adverse events noted:

  • Headache
  • Disturbed sleep
  • Mild gastro intestinal disturbances
  • Agitation
  • Decreased appetite
  • Exacerbation of psychosis

Only one case of exacerbation of psychosis was noted in the study, patient was on Modafinil, patient was taken out of the study because of psychosis and treated promptly. This one stray incident of exacerbation could possibly due to the disease natural course itself. This finding is unlike what was observed with anti obesity drugs.

Impact of Modafinil on Daytime Sedation

In the recent literature there was no study available which attempted to reduce the daytime drowsiness, produced by atypicals. There were only three case reports of using modafinil to reduce the sedation induced by antipsychotic medication, which showed that Modafinil could be possibly a drug advised to be added to atypical antipsychotics.

In this study, two scales to measure the drowsiness were used. A subjective scale having two components, one is to assess the sleep quality and other is the daytime drowsiness. Another was objective scale where examiner asks few structured questions would decide about the duration of the drowsiness and also intensity of the excessive daytime drowsiness.

In the study only on subjective scale there was improvement in the quality of sleep, and also improvement in the daytime drowsiness in Modafinil group.But same findings not found with the objective scale.

The improvement of quality of sleep could have been due to the fact that patients improved in their psychotic features as evidenced by BPRS scores. But Modafinil, definitely may significantly decrease in the daytime drowsiness. The same was not reflected when this finding was looked in objective manner using EDD scale. This particular finding requires further exploration, as the patient suffering from psychosis, when they responded to a structured questionnaire, might not have answered adequately. However in future studies the correlation between subjective and objective scales must be studied and the reasons ascertained.

The very fact that subjectively patients feel that their daytime drowsiness would have improved, clinically it indicates that it may improve the drug compliance.

Impact of Modafinil on Weight and Other Physical Parameters

Many studies and clinical evidence proves that treatment with atypicals causes significant weight gain over a period of time.

In the literature, there was a case report where a patient on clozapine was added with modafinil, and patient was followed up to three years. Patient experienced a weight loss of 40 lbs over a period of three years. When modafinil was discontinued for a period of six months, he again put on 30 lbs of weight. Reinstitution of modafinil for the period of six weeks resulted in ten lbs weight loss. The authors strongly recommended randomized clinical trials to evaluate the safety and efficacy of modafinil, for clozapine associated weight gain.

However till to date there were no other randomized clinical trials on modafinil for either clozapine or other antipsychotic associated weight gain. In the present study the patients who were put on 200mg of modafinil at both points of evaluation at 3weeks and 12 weeks showed a significant weight loss, compared to baseline.

The placebo group, did not show a similar weight loss, but when the groups were compared each other for weight loss in reference to the baseline the results were not that significant. These findings require further evaluation as it was possible that at baseline itself maximum weight gain already occurred in the placebo group. This particular aspect could not be verified from the existing data, as there was a possibility that placebo group used atypicals for longer periods than modafinil group. Patients when entering into the study were on different doses of atypicals. Dose of atypical antipsychotic was not considered during the study period as it was kept flexible.

When abdominal girth was calculated at the umbilicus level the placebo group showed statistically significant raise from baseline to week 3 and week 12. BMI also showed a similar trend. The same finding was not found in the modafinil group. This suggested that weight loss seen in modafinil group considered as clinically significant and relevant and not apparent. The other drugs where RCTs were conducted in reducing antipsychotic induced weight gain were extensive with Topiramate.

In this study no attempt was made to measure any cognitive changes with modafinil in comparison to placebo as the population constituted the multiple diagnoses and more than one antipsychotic, already some studies are in progress which are looking at modafinil as a cognitive enhancer in schizophrenia.

In conclusion the results of this study suggest that modafinil even at a dosage of 200 mg is efficacious adjuvant treatment in controlling atypical antipsychotic induced weight gain and some of the metabolic parameters. It was found to be well tolerated without major side effects. Further clinical research is necessary to prove the fact that modafinil is an effective add on therapy. A higher dose of Modafinil should also be explored in those who could tolerate it.

   Conclusion Top

Present study was a randomized, placebo controlled trail, using a double blind technique . Findings point out the Modafinil could be a potential candidate in selected group of patients to decrease some of the unwanted adverse events like weight gain, daytime drowsiness and metabolic syndrome produced by atypicals. However as the sample size was small and many atypicals were included, and the population studied was not homogeneous for the duration of drug therapy ,and as the study duration was 12 weeks, this study findings definitely requires future replication.

In the light of present findings a multi center randomized study using a good comparator like Topiramate, which had proven efficacy in decreasing weight and also using some robust objective clinical instrument to measure daytime drowsiness, have to be under taken, using a bigger sample.

Limitations of the Study

  • This was a convenient sample.
  • Consented people, at least few of them were more motivated and Modafinil might have motivated them to change their food habits and life style.
  • A large sample than this concentrating on one Atypical drug would have decisively answered the Hypothesis.
  • Crossover at the end of twelve weeks from placebo to Modafinil and vice versa for the next twelve weeks would have strongly established the role of Modafinil as an useful add on.
  • No active comparator was used as a third arm to make sure that changes with Modafinil were not apparent.
  • The dosage of Modafinil was fixed in the study. A flexible dosage ranges higher than 200mg might have further influenced the outcome of the study.
  • The improvement in psychosis, might have contributed as body image changes were not studied between the groups.
  • Drug attitude inventory could not be applied - Hence acceptability of Modafinil as an add-on could not be studied.

strengths of the Study

  1. It was a Double blind placebo controlled study -hence there were minimum chances for bias.
  2. Randomization was done centrally by an outside agency decreased chance for bias.
  3. Two centered study - Wider populations were covered.
  4. Covered two scales for drowsiness i.e. both subjective and objective scales
  5. In addition to physical parameters, biochemical parameters were also correlated.[9]

   References Top

1.Allison DB, Mentore JL, Heo M, et al(1999) Antipsychotic­induced weight gain: a comprehensive research synthesis. American Journal of Psychiatry;156: 1686-1696  Back to cited text no. 1    
2.Coodin S (2001). Body mass index in persons with schizophrenia. Canadian Journal of Psychiatry; 46;549-555.  Back to cited text no. 2    
3.Janssen P.A.J., Niemegeers C.J.E. and Awouters F. et al [1988]. Pharmacology of risperidone [R64-766] a new antipsychotic with serotonin and dopamine -D2 antagonistic properties. Journal of Pharmacology.  Back to cited text no. 3    
4.John W. Newcomer, MD Metabolic effects of Antisychotics; Results from the CATIE study.  Back to cited text no. 4    
5.John W. Newcomer, MD Metabolic effects of Antisychotics; Results from the CATIE study. Medscape CME  Back to cited text no. 5    
6.Lambert MT; Copeland LA; Sampson N;Duffy SA(2006) New onset type 2 DM associated with atypical antipsychotic medication, Progress of Neuropsychopharmacology and Biological Psychiatry. 30(5):919-23.  Back to cited text no. 6    
7.Makela EH, Miller K, Cutlip WD. Three case reports of modafinil use in treating sedation induced by antipsychotic medication. Clin Psychiatry 2003;64:485­  Back to cited text no. 7    
8.Massachusetts General Hospital Schizoprenia Programme, Freedom trail clinic,Boston, MA 02114, USA.(2005)Modafinil associated weight loss in clozapine-treated schizoaffective disorder patient.;Arr-Jun;17(2):95-97.  Back to cited text no. 8    
9.McKee JR, Bodfish JW, Mahorney SL, et al (2005) Metabolic effects associated with atypical antipsychotics. J Clin Psychiatry; 66(9):1161-8.  Back to cited text no. 9    


  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9], [Table 10]

This article has been cited by
1 Wake-Promoting Pharmacotherapy for Psychiatric Disorders
Bernardo Dell’Osso,Cristina Dobrea,Laura Cremaschi,Chiara Arici,A. Carlo Altamura
Current Psychiatry Reports. 2014; 16(12)
[Pubmed] | [DOI]
2 Pharmacological Strategies to Counteract Antipsychotic-Induced Weight Gain and Metabolic Adverse Effects in Schizophrenia: A Systematic Review and Meta-analysis
Y. Mizuno,T. Suzuki,A. Nakagawa,K. Yoshida,M. Mimura,W. W. Fleischhacker,H. Uchida
Schizophrenia Bulletin. 2014;
[Pubmed] | [DOI]
3 Effects of modafinil on weight, glucose and lipid metabolism in clozapine-treated patients with schizophrenia
David C. Henderson, Oliver Freudenreich, Christina P.C. Borba, Xingyue Wang, Paul M. Copeland, Eric Macklin, Xiaoduo Fan, Corinne Cather, Donald C. Goff
Schizophrenia Research. 2011;
[VIEW] | [DOI]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

  In this article
    Review of Literature
    Materials and Me...
    Scales used in t...
    Article Tables

 Article Access Statistics
    PDF Downloaded184    
    Comments [Add]    
    Cited by others 3    

Recommend this journal