Table 3.

The types of animal model in the comorbidity of depression and addiction.

Disorder	Model	Characteristic	Reference
Addiction	Self-administration (SA)	The animals were trained to obtain an intravenous fluid injection by performing operant response, for example pressing a lever or the inserting its snout into a hole.	Li et al. (2018)
Addiction	Intracranial self-stimulation (ICSS)	This procedure is based on the observation that rats will press a lever to pass a small current through electrodes located in various brain areas.	Melis et al. (2005)
Addiction	conditioned place preference (CPP)	A Pavlovian conditioning procedure inwhich the animal learns to prefer an environment that is paired with drug effects.	Siahposht-Khachaki et al. (2016)
Depression	Chronic social defeat stress (CSDS) model	CSDS simulates the pathogenesis of depression at a social level. With a frequently performed stimulation, model rodents manifest a stress response to produce long-term behavioral and psychosocial change.	Koo et al. (2019)
Depression	Olfactory bulbectomy (OBX) model	The bilateral ablation of the olfactory bulbs was performed, it is a well-established model of depression with high face, construct, and predictive validity which closely mimics neurochemical, neuroanatomical, behavioral and endocrine changes seen in patients with major depression.	Babinska et al. (2016)
Depression	p11 KO model	p11 loss within neurons of the NAc induces depression-like behaviors.	Alexander et al. (2010)
Depression	The KOR agonies induce depression-like behavior	SalvA increased ICSS thresholds and significantly lowered breakpoint on the progressive ratio schedule, indicating a decrease in motivation.	Ebner et al. (2010)
Depression	Chronic restraint stress	Animals are placed in restraint tubes for several hours daily, repeated over several days.	Thompson et al. (2015)
Comorbidity	The KOR agonist +CPP	Stress-induced activation of KOR by endogenous dynorphin opioids may enhance the rewarding valence of drugs of abuse by potentiating the evoked dopamine response.	Ehrich et al. (2014)
Comorbidity	Chronic mild restraint (CMR)+morphine-CPP	Rats undergoing CMR, which were evaluated for novelty-seeking, forced open-space swimming, and locomotor activity to validate CMR as a depression- like model Rats undergoing CMR were trained for morphine-induced CPP.	Gao et al. (2012)
Comorbidity	OBX model + intravenous self-administration	A rat model of depression and addiction dual disorder where olfactory bulbectomized animals was developed and it showed a significantly higher vulnerability in methamphetamine intravenous self-administration (IVSA) paradigm.	Babinska et al. (2016)
Comorbidity	CSDS + SA	The activational effect of ostensibly aversive events such as social stress on the acquisition of cocaine self-administration, an intensely reinforcing event, prompts a closer scrutiny of the behavioral features that may inform on the reinforcing efficacy of the drug.	Miczek and Mutschler (1996)
Comorbidity	CSDS+CPP	SDS has also been shown to enhance the sensitivity to cocaine CPP.	Ribeiro Do Couto et al. (2009)
Comorbidity	GSK3β knockdown	Knocked down GSK3β expression with a novel adeno-associated viral vector (AAV2) and assessed changes in anxiety- and depression-like behavior and cocaine self-administration in GSK3β knockdown rats.	Crofton et al. (2017)
Comorbidity	P11 KO +SA	It may be a comorbid model, but experiments are needed to prove whether it can be a comorbid model.	Warner-Schmidt et al. (2012)
Comorbidity	CHT+/– mice+SA	It may be a comorbid model, but experiments are needed to prove whether it can be a comorbid model.	Dong et al. (2013)