Depression and anxiety disorders are highly prevalent, affecting individuals, their families and the individual’s role in society (Birgitta et al., 2018). Depression is a disabling and costly condition associated with a significant reduction in quality of life, medical comorbidities and mortality (Demyttenaere et al., 2004; Whiteford et al., 2013; Cuijpers et al., 2014). Anxiety is associated with lower quality of life and negative effects on psychosocial functioning (Cramer et al., 2005). Medication is the most commonly used effective way to relieve symptoms of depression and anxiety. However, nonadherence are crucial shortcomings in using antidepressant to treat depression and anxiety (van Geffen et al., 2007; Nielsen et al., 2019).

In recent years, many studies have shown that art therapy plays a significant role in alleviating depression symptoms and anxiety. Gussak (2007) performed an observational survey about populations in prison of northern Florida and identified that art therapy significantly reduces depressive symptoms. Similarly, a randomized, controlled, and single-blind study about art therapy for depression with the elderly showed that painting as an adjuvant treatment for depression can reduce depressive and anxiety symptoms (Ciasca et al., 2018). In addition, art therapy is also widely used among students, and several studies (Runde, 2008; Zhenhai and Yunhua, 2011) have shown that art therapy also significantly reduces depressive symptoms in students. For example, Wang et al. (2011) conducted group painting therapy on 30 patients with depression for 3 months, and found that painting therapy could promote their social function recovery, improve their social adaptability and quality of life. Another randomized clinical trial also showed that it could decrease mean anxiety scores in the 3–12 year painting group (Forouzandeh et al., 2020).

Studies have shown that distress, including anxiety and depression, is related to poorer health-related quality of life and satisfaction to medical services (Hamer et al., 2009). Painting can be employed to express patients’ anxiety and fear, vent negative emotions by applying projection, thereby significantly improve the mood and reduce symptoms of depression and anxiety of cancer patients. A number of studies (Bar-Sela et al., 2007; Thyme et al., 2009; Lin et al., 2012; Abdulah and Abdulla, 2018) showed that art therapy for cancer patients could enhance the vitality of patients and participation in social activities, significantly reduce depression, anxiety, and reduce stressful feelings. Importantly, even in the follow-up period, art therapy still has a lasting effect on cancer patients (Thyme et al., 2009). Interestingly, art therapy based on famous painting appreciation could also significantly reduce anxiety and depression associated with cancer (Lee et al., 2017). Among cancer patients treated in outpatient health care, art therapy also plays an important role in alleviating their physical symptoms and mental health (Götze et al., 2009). Therefore, art therapy as an auxiliary treatment of cancer is of great value in improving quality of life.

Overall, art painting therapy permits patients to express themselves in a manner acceptable to the inside and outside culture, thereby diminishing depressed and anxiety symptoms.

Dementia, a progressive clinical syndrome, is characterized by widespread cognitive impairment in memory, thinking, behavior, emotion and performance, leading to worse daily living (Deshmukh et al., 2018). According to the Alzheimer’s Disease International 2015, there is 46.8 million people suffered from dementia, and numbers almost doubling every 20 years, rising to 131.5 million by 2050. Although art therapy has been used as an alternative treatment for the dementia for long time, the positive effects of painting therapy on cognitive function remain largely unknown. One intervention assigned older adults patients with dementia to a group-based art therapy (including painting) observed significant improvements in the clock drawing test (Pike, 2013), whereas two other randomized controlled trials (Hattori et al., 2011; Rusted et al., 2016) on patients with dementia have failed to obtain significant cognitive improvement in the painting group. Moreover, a cochrane systematic review (Deshmukh et al., 2018) included two clinical studies of art therapy for dementia revealed that there is no sufficient evidence about the efficacy of art therapy for dementia. This may be because patients with severely cognitive impairment, who was unable to accurately remember or assess their own behavior or mental state, might lose the ability to enjoy the benefits of art therapy.

In summary, we should intervene earlier in patients with mild cognitive impairment, an intermediate stage between normal aging and dementia, in order to prevent further transformation into dementia. To date, mild cognitive impairment is drawing much attention to the importance of painting intervening at this stage in order to alter the course of subsequent cognitive decline as soon as possible (Petersen et al., 2014). Recently, a randomized controlled trial (Yu et al., 2021) showed significant relationship between improvement immediate memory/working memory span and increased cortical thickness in right middle frontal gyrus in the painting art group. With the long-term cognitive stimulation and engagement from multiple sessions of painting therapy, it is likely that painting therapy could lead to enhanced cognitive functioning for these patients.

Alzheimer’s disease (AD) is a sub-type of dementia, which is usually associated with chronic pain. Previous studies suggested that art therapy could be used as a complementary treatment to relief pain for these patients since medication might induce severely side effects. In a multicenter randomized controlled trial, 28 mild AD patients showed significant pain reduction, reduced anxiety, improved quality of life, improved digit span, and inhibitory processes, as well as reduced depression symptoms after 12-week painting (Pongan et al., 2017; Alvarenga et al., 2018). Further study also suggested that individual therapy rather than group therapy could be more optimal since neuroticism can decrease efficacy of painting intervention on pain in patients with mild AD. In addition to release chronic pain, art therapy has been reported to show positive effects on cognitive and psychological symptoms in patients with mild AD. For example, a controlled study revealed significant improvement in the apathy scale and quality of life after 12 weeks of painting treatment mainly including color abstract patterns with pastel crayons or water-based paint (Hattori et al., 2011). Another study also revealed that AD patients showed improvement in facial expression, discourse content and mood after 3-weeks painting intervention (Narme et al., 2012).

Schizophrenia is a complex functional psychotic mental illness that affects about 1% of the population at some point in their life (Kolliakou et al., 2011). Not only do sufferers experience “positive” symptoms such as hallucinations, delusions, but also experience negative symptoms such as varying degrees of anhedonia and asociality, impaired working memory and attention, poverty of speech, and lack of motivation (Andreasen and Olsen, 1982). Many patients with schizophrenia remain symptomatic despite pharmacotherapy, and even attempts to suicide with a rate of 10 to 50% (De Sousa et al., 2020). For these patients, art therapy is highly recommended to process emotional, cognitive and psychotic experiences to release symptoms. Indeed, many forms of art therapy have been successfully used in schizophrenia, whether and how painting may interfere with psychopathology to release symptoms remains largely unknown.

A recent review including 20 studies overall was performed to summary findings, however, concluded that it is not clear whether art therapy leads to clinical improvement in schizophrenia with low (Ruiz et al., 2017). Anyway, many randomized clinical trials reported positive outcomes. For example, Richardson et al. (2007) conducted painting therapy for six months in patients with chronic schizophrenia and found that art therapy had a positive effect on negative symptoms. Teglbjaerg (2011) examined experience of each patient using interviews and written evaluations before and after painting therapy and at a 1-year follow-up and found that group painting therapy in patients with schizophrenia could not only reduce psychotic symptoms, but also boost self-esteem and improve social function.

What’s more, the characteristics of the painting can also be used to judge the health condition in patients with schizophrenia. For example, Hongxia et al. (2013) explored the correlation between psychological health condition and characteristics of House-Tree-Person tests for patients with schizophrenia, and showed that the detail characteristic of the test results can be used to judge the patient’s anxiety, depression, and obsessive-compulsive symptoms.

Most importantly, several other studies showed that drug plus painting therapy significantly enhanced patient compliance and self-cognition than drug therapy alone in patients with schizophrenia (Hongyan and JinJie, 2010; Min, 2010).

Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental syndrome with no unified pathological or neurobiological etiology, which is characterized by difficulties in social interaction, communication problems, and a tendency to engage in repetitive behaviors (Geschwind and Levitt, 2007).

Art therapy is a form of expression that opens the door to communication without verbal interaction. It provides therapists with the opportunity to interact one-on-one with individuals with autism, and make broad connections in a more comfortable and effective way (Babaei et al., 2020). Emery (2004) did a case study about a 6-year-old boy diagnosed with autism and found that art therapy is of great value to the development, growth and communication skills of the boy. Recently, one study (Jalambadani, 2020) using 40 children with ASD participating in painting therapy showed that painting therapy had a significant improvement in the social interactions, adaptive behaviors and emotions. Therefore, encouraging children with ASD to express their experience by using nonverbal expressions is crucial to their development. Evans and Dubowski (2001) believed that creating images on paper could help children express their internal images, thereby enhance their imagination and abstract thinking. Painting can also help autistic children express and vent negative emotions and thereby bring positive emotional experience and promote their self-consciousness (Martin, 2009). According to two studies (Wen and Zhaoming, 2009; Jianhua and Xiaolu, 2013) in China, Art therapy could also improve the language and communication skills, cognitive and behavioral performance of children with ASD.

Moreover, art therapy could be used to investigate the relationship between cognitive processes and imagination in children with ASD. One study (Wen and Zhaoming, 2009; Jianhua and Xiaolu, 2013) suggested that children with ASD apply a unique cognitive strategy in imaginative drawing. Another study (Low et al., 2009) examined the cognitive underpinnings of spontaneous imagination in children with ASD and showed that ASD group lacks imagination, generative ability, planning ability and good consistency in their drawings. In addition, several studies (Leevers and Harris, 1998; Craig and Baron-Cohen, 1999; Craig et al., 2001) have been performed to investigate imagination and creativity of autism via drawing tasks, and showed impairments of autism in imagination and creativity via drawing tasks.

In a word, art therapy plays a significant role in children with ASD, not only as a method of treatment, but also in understanding and investigating patients’ problems.

In addition to the above mentioned diseases, art therapy has also been adopted in other applications. Dysarthia is a common sequela of cerebral palsy (CP), which directly affects children’s language intelligibility and psycho-social adjustment. Speech therapy does not always help CP children to speak more intelligibly. Interestingly, the art therapy can significantly improve the language intelligibility and their social skills for children with CP (Wilk et al., 2010).

In brief, these studies suggest that art therapy is meaningful and accepted by both patients and therapists. Most often, art therapy could strengthen patient’s emotional expression, self-esteem, and self-awareness. However, our findings are based on relatively small samples and few good-quality qualitative studies, and require cautious interpretation.