Observational Study
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World J Psychiatry. Jul 19, 2022; 12(7): 944-957
Published online Jul 19, 2022. doi: 10.5498/wjp.v12.i7.944
Treatment outcome, cognitive function, and psychopathology in methamphetamine users compared to other substance users
Nina Behle, Felicia Kamp, Lisa Proebstl, Laura Hager, Marlies Riebschläger, Maik Schacht-Jablonowsky, Willem Hamdorf, Stefanie Neumann, Daniela Krause, Kirsi Manz, Andreas Guenter Franke, Gabriele Koller, Michael Soyka
Nina Behle, Felicia Kamp, Lisa Proebstl, Laura Hager, Daniela Krause, Department of Psychiatry and Psychotherapy, Ludwig Maximilians University, Munich 80336, Germany
Marlies Riebschläger, Maik Schacht-Jablonowsky, Willem Hamdorf, Stefanie Neumann, MEDIAN Clinic, Mecklenburg, Vitense 19217, Germany
Kirsi Manz, Institute for Medical Information Processing, Ludwig Maximilians University, Munich 81377, Germany
Andreas Guenter Franke, University of Applied Labour Studies of the Federal Employment Agency, Mannheim 68163, Germany
Gabriele Koller, Michael Soyka, Department of Psychiatry, Ludwig Maximilians University, Munich 80336, Germany
Author contributions: Koller G and Soyka M were responsible for the study concept and design; Behle N and Kamp F wrote the manuscript; Behle N, Kamp F, Proebstl L, Hager L, Riebschläger M, Schacht-Jablonowsky M, Hamdorf W, and Neumann S performed the research and data collection; Behle N, Kamp F and Manz K performed data analysis; Behle N, Kamp F, and Krause D interpreted the analyses outcomes; Koller G, Soyka M, Franke AG, and Krause D reviewed and edited the manuscript; All authors critically reviewed content and approved final version for publication.
Supported by the German Federal Ministry of Health (partially).
Institutional review board statement: Institutional review board statement: The study was reviewed and approved by ethic committee of LMU Munich, Project No. 422-16.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: All authors declare no conflict of interests for this article.
Data sharing statement: Data are available from the corresponding author at gabi.koller@med.uni-muenchen.de. Consent for data sharing was not obtained but the presented data are anonymized and risk of identification is low.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Gabriele Koller, MD, Attending Doctor, Department of Psychiatry, Ludwig Maximilians University, Nußbaumstraße 7, Munich 80336, Germany. gabi.koller@med.uni-muenchen.de
Received: December 22, 2021
Peer-review started: December 22, 2021
First decision: March 13, 2022
Revised: March 28, 2022
Accepted: June 16, 2022
Article in press: June 16, 2022
Published online: July 19, 2022
Processing time: 208 Days and 11 Hours
Abstract
BACKGROUND

The rising number of people using methamphetamine leads to an increasing need for treatment options for this patient group. Evidence-based research on the efficacy of treatment programs for methamphetamine users is limited. Due to specific characteristics of methamphetamine users, the question arises whether established treatment methods for individuals using other substances can be effective for the treatment of methamphetamine dependence as well. We hypothesize that there are significant differences between the two groups that may affect the effectiveness of treatment and worsen the prognosis of treatment outcomes for methamphetamine users compared to consumers of other substances.

AIM

To investigate potential differences in cognitive functioning and psychopathology between methamphetamine users and other substance users and possible correlations with treatment outcomes.

METHODS

A total of 110 subjects were recruited for an observational, longitudinal study from a German inpatient addiction treatment center: 55 patients with methamphetamine dependence and 55 patients with dependence of other substances (“OS group”). Both groups were examined at beginning (baseline) and end of treatment (after 6 mo) with regard to treatment retention, craving, cognitive functioning, psychosocial resources, personality traits, depression, and other psychiatric symptoms. Instruments used were Raven’s IQ test, Mannheimer craving scale, cognitrone cognitive test battery, NEO personality factors inventory, Hamilton depression scale, Becks depression inventory, and a symptom checklist. The statistical methods used were χ2-test, t-test and multiple mixed ANOVAs.

RESULTS

A total drop-out rate of 40% (methamphetamine-group: 36.4%; OS-group: 43.6%) was observed without significant differences between groups. At baseline, methamphetamine-group subjects significantly differed from OS-group individuals in terms of a lower intelligence quotient, fewer years of education, slower working speed, and decreased working accuracy, as well as less cannabinoid and cocaine use. Methamphetamine-group subjects further showed a significantly lower score of conscientiousness, depressive, and psychiatric symptoms than subjects from the OS-group. In both groups, a reduction of craving and depressive symptoms and an improvement of working speed and working accuracy was noted after treatment.

CONCLUSION

There are differences between methamphetamine users and users of other drugs, but not with regard to the effectiveness of treatment in this inpatient setting. There are differences in cognitive function and psychopathology between methamphetamine and other drugs users. The existing treatment options seem to be an effective approach in treating methamphetamine dependence.

Keywords: Treatment outcome; Cognitive function; Psychopathology; Methamphetamine; Substance use; Comparison

Core Tip: There are differences between methamphetamine users and users of other drugs, but not with regard to the effectiveness of treatment in this inpatient setting. The existing treatment options seem to be an effective approach in treating methamphetamine dependence.